MEMOIRS
California Academy of Sciences
Volume III
MEMOIRS
OF THE
California Academy of Sciences
Volume III
THE PALEONTOLOGY AND STRATIGRAPHY OF THE
MARINE PLIOCENE AND PLEISTOCENE
OF SAN PEDRO, CALIFORNIA
By RALPH ARNOLD
Issued June 27, 1903
SAN FRANCISCO
Published uy the Acade:\iv
1903
'T
^^ 7 /
THE PALEONTOLOGY AND STRATIGRAPHY OF THE MARINE PLIOCENE AND PLEISTOCENE OF SAN PEDRO,
CALIFORNIA.
BY RALPH ARNOLD.
CONTENTS. Plates I-XXXVII.
Page
Introduction and Acknowledgments 9
Pabt I. Genekax Discussion.
CHAPTER I. TOPOGRAPHY AND GEOLOGY OF SAN PEDRO 11
1 . Topography 11
2. General Geology 12
3. Pliocene 14
Deadman Island 14
Timings Point 17
4. Pleistocene 17
The San Pedro Series 17
Lower San Pedro Series 18
Upper San Pedro Series 23
Raised Beach Formation 33
5. Post-Pleistocene Deposits 33
6. Alphabetical List showing the DisTRiBnTiON of Specie-s in the vicinity of San Pedro... 34
CHAPTER ir. THE UPPER PLIOCENE AND PLEISTOCENE FORMATIONS OF OTHER LOCALITIES
ON THE PACIFIC COAST 48
PoGET Sound South to Pismo, San Luis Obispo County 48
Santa Barbara and Vicinity South to San Joan Capistrano 50
Ventura 53
Port Los Angeles 56
San Clemenle Island 56
Newport 56
San Juan Capistrano 57
San Diego and Vicinity .'. 57
Pacific Beach — Pliocene 57
Pacific Beach — Pleistocene .' 58
San Dier/o Mesa — Pliocene 59
Twenty-sixth Street — Pleistocene 59
Spanish Biijht —Pleistocene 59
CHAPTER IIL FAUNAE RELATIONS 65
1. Pliocene 65
2. -Pleistocene 66
The Loicer San Pedro Series 66
The Upper San Pedro Series 66
3. Relation of the Late Pliocene, Pleistocene, and Living Faunas of California to the
Fauna of Japan 6¥
(7)
8 CALIFORNIA ACADEMY OF SCIENCES.
Pabt II. The I'liocknk and Pleistocene Fauna of San Pedro and Vicinity.
Synopsis 71
De.scrii'tion of Species 80
Pabt III. Bibliography.
Explanation of Plates 364
Index 405
INTRODUCTION AND ACKNOWLEDGMENTS.
Errata
Page 107, last line, after (Cooper) insert San Pedro; Santa Barbara (Arnold).
Page 112, 17th line, for " Jlucicolus" re&d fucicolus.
Page 142, last line, after Cytherea insert radiata Sby.
Page 144, 4th line from bottom, after Carpenter insert var.
Page 145, 4th line, for "C diaphana" read C. subdiaphana.
Page, 166, i2th line from bottom, after Sowerby insert var.
Page 185, top line u{ foot-note, lor " Dr. W. N. Dall " read Dr. W. H. Dall.
Page 233, nth line from bottom, for ",!/. woodwardi" read N. wood'cvardi, and for " gibbsW" read gibbesii.
Page 243, 5th line, for " feniuspe7ia'' read tenuispina.
Page 253, 7th line, for " stuarti Smith var." read orpheus var.
Page 307, 17th and 19th lines, for '' Calyptrea" read Calyptrcea.
Page 339, 3rd line, for " Fissuridiz" read Fissuridea.
Besides the collection of Delos Arnold, the writer has had access to tlie collections or material belonging to the following institutions or individuals:
1. Leland Stanford Junior University: Geological Department collections.
2. University of California: Geological Department collections, State Geo- logical Survey collections, and State Mining Bureau collections.
3. California Academy of Sciences: Paleontological and Conchological collections.
4. The private collection of Mrs. M. Burton Williamson, Los Angeles?, California.
5. The private collection of Mrs. T. S. Oldroyd, Los Angeles, California. (). The private collection of Mr. Henry Hemphill, San Diego, California.
C 2 I ( 9 J September 22, 1902.
8 CALIFORNIA ACADEMY OF SCIENCES.
Paet II. The Pliocenk and Pi^eistocene Fauna of San Pedro amj Vicinity.
Synopsis '1
Description of Species 86
Pakt III. Bibliography.
INTRODUCTION AND ACKNOWLEDGMENTS.
The field work upon which this paper is based began in the winter of 1886, when the writer first visited the fossil-bearing beds of San Pedro. Since that time several visits have been made each year to the beds in that vicinity, generally after heavy rains, when landslides and the breaking off of the banks have given new exposures. The specimens obtained during these excursions are in the collection of the writer's father, Delos Arnold of Pasadena, California, and have furnished most of the material on which the present paper is based. It was first intended to compile a list, with synonymy, of the fossils of San Pedro and vicinity, but the scope of the paper has been enlarged until the present work is the result.
One of the obstacles met with in the preparation of this work has been the lack of systematic information in regard to the fauna and stratigraphy of the Pleisto- cene of the Pacific Coast. Dall, Cooper, Gabb, Ashley and Merriam have published notes on the faunal aspects of the marine Pleistocene of the coast of California; while Whitney, Lawson, Fairbanks and Ashley have contributed to our knowledge of the geology and stratigraphy of the Pleistocene. The inadequacy of these observations has led the writer to visit as many localities as possible in the endeavor to obtain information that would add to the knowledge of the Pliocene and Pleistocene of California. Enough evidence was obtained at the different points along the coast to warrant the statement that we have in the California deposits the greatest develop- ment of the marine Pleistocene in the world. Future investigations are necessary in order to give more accurately the thickness of the sediments deposited and the amount of orogenic movement which has taken place since the beginning of the Pleistocene epoch. The future study of the Pleistocene fauna will no doubt add greatly to our knowledge of the relations existing between the Tertiary and living faunas.
Besides the collection of Delos Arnold, the writer has had access to the collections or material belonging to the following institutions or individuals:
1. Leland Stanford Junior University: Geological Department collections.
2. University of California: Geological Department collections. State Geo- logical Survey collections, and State Mining Bureau collections.
3. California Academy of Sciences: Paleontological and Conchological collections.
4. The private collection of Mrs. M. Burton Williamson, Los Angeles, California.
5. The private collection of Mrs. T. S. Oldroyd, Los Angeles, California.
6. The private collection of Mr. Henry Hemphill, San Diego, California.
(21 [ 9 ] September 22, 1S02.
10 CALIFORNIA ACADEMY OF HCIENCES.
Dr. James Perrin Smith, Professor of Paleontology in Leland Stanford Junior Universit}', has had general supervision of this paper during its preparation. He has accompanied the writer on journeys that covered much of the territory under dis- cussion, and has offered many valuable suggestions regarding the faunal relations and stratigraphy of the San Pedro formations.
The writer is indebted to Dr. John C. Branner, Professor of Geology in Leland Stanford Junior University, for valuable suggestions in regard to the field work and compilation of this paper.
Dr. William Healey Dall, of the United States National Museum, has identified numerous specimens sent to him, acknowledgment for which is given with each species. Dr. Dall has also prepared the diagnoses of the family Pyrami- dellidse, and has furnished drawings of the species of that family, and for the corals; and in many otli.er ways has extended courtesies during the preparation of this work.
Dr. John C. Merriam, of the University of California, has given free access to all of the collections under his charge; has extended many other courtesies; and has offered suggestions which have added to the value of the paper.
The writer is indebted to his father, Delos Arnold, for the use of his collec- tion; for notes and suggestions on the stratigraphy of the San Pedro deposits; for assistance in the prej^aration of the drawings; and, most of all, for the interest mani- fested by him in procuring the material upon which much of this paper is based. The field work and collecting has been done as much by him as by the writer. For the past fifteen years he has made numerous visits each year to the San Pedro beds, and to his untiring efforts is due the discovery of such a large number of species in them. He has also visited and made systematic collections from the deposits of Santa Barbara, Ventura, San Diego and other localities along the southern California coast.
Acknowledgment is also due to Mr. T. Wayland Vaughan, Dr. R. E. C. Stearns, Mr. Henry Hemphill, Dr. A. A. Wright, Mr. J. Howard Wilson, and others.
The illustrations are from drawings by Dr. J. C. McConnell, Misses Winnifred M. Paine and Fanny H. Mitchell, Messrs. H. R. Johnson, R. E. Renaud and R. Arnold.
Where the types of new species belonged to Delos Arnold, these types have been deposited in the United States National Museum at Washington, and, where possible, duplicates will be dej^osited in the paleontological collections of the California Academy of Sciences, and of Leland Stanford Junior University.
Pakt I. General Discussiox.
Chapter I.
TOPOGRAPHY AND GEOLOGY OF SAN PEDRO
1. Topography.
The most prominent topographic feature about San Pedro is San Pedro Hill, an abruptly projecting headland of the coast, rising to a height of 1,482 feet. Along its southern base is a sea clifi varying in height from one hundred to three hundred feet, while to the east the cliff rarely exceeds fifty feet in height. The hill is ter- raced to within two hundred and forty feet of its summit, and the observations here recorded began on the lowest, or fifty-foot terrace, at the eastern limit of the hill. (See map, Plate XXIII.)
This terrace extends from a point about one-half mile east of the Point Fer- min lighthouse to a bluft' about a half mile north of the business center of the town of San Pedro. The sea cliff bounding this terrace runs due north for nearly a mile and a half from Point Fermi n, then bends abruptly at old San Pedro, popularly known as " Crawfish George's," and runs northeastward for half a mile to Timm's Point. From this point the bluf! runs due north for over a mile, broken only by a little valley in which the business portion of San Pedro is located. At the north end of this bluff the escarpment bends sharjily toward the northwest, and is broken along the north- ern front by several valleys that run down from San Pedro Hill.
Half a mile southeast of Timm's Point is Deadman Island, a small fragment of the San Pedro terrace, which has withstood the eroding agents that have cut it off from the mainland, but which is now being worn away rapidly by the waves. It is a triangular bit of land about fifty feet high, with an area on top of about three hundred square yards. Deadman Island is joined by a breakwater to Rattlesnake Island, or Terminal Island, as it is now called, a narrow barrier beach, which begins at a point directly opposite San Pedro and runs to Old River — the former mouth of the Los Angeles River — about four miles distant.
About a mile east from Old River a ten-foot bank forms the eastern limit of the marsh lands and the western edge of a plain that rises toward the east for about three and a quarter miles, where it is terminated by a bluff. The bluff, which forms the coast-line of this plain, gradually rises in height from ten feet at its western ex- tremity to over fifty feet at about its middle. The eastern half is of a nearly uniform height of fifty feet.
The town of Long Beach is situated on the plain that slopes gradually back
[11]
12 CALIFORNIA ACADEMY OF SCIENCES.
from this bluff. Two and a half miles north of Long Beach is Los Cerritos, or Signal Hill, as it is commonly called, the most prominent point in a series of low hills extending to Dominguez Hill, six miles to the northwest. Los Cerritos is three hundred and sixty-four feet high. Its northern side is smooth and slopes gently into the great Los Angeles plain. Its southern slope is much steeper, and is cut by many deep, narrow ravines, which offer a fine opportunity for studying the geology of the hill.
2. General Geology.
The oldest formation exposed in the immediate vicinity of San Pedro is the Miocene, or Monterey series. The shales of this formation are exposed along the sea cliff on the eastern end of San Pedro Hill, and also at Deadman Island. After the deposition of the Miocene the shale beds were raised and contorted and subjected to erosion. During the Pliocene period a submergence took place and a deposit of fine, yellow, clayey sand of unknown thickness was laid down on the surface of the eroded Miocene shales.
A post-Pliocene uplift laid bare the sandstones, which were worn away com- pletely from some parts of the eastern base of San Pedro Hill. Timra's Point and Deadman Island are the only places at which they are now exposed.
Again there was a change of conditions. The eroded surface of the Pliocene became sea bottom, and deposits of fine, gray, silicious sand, extremely fossiliferous in places, were laid down unconformably on it. This particular horizon is repre- sented by the gray sand deposit of Deadman Island, by the gray, sandy strata exposed along the bluff southeast of San Pedro and in the lower part of the continua- tion of this bluff just north of the San Pedro valley. The lower series of sandstones and conglomerates of Los Cerritos may be contemporaneous with these last men- tioned beds. On account of its fauna and its unconformable position on the Pliocene this horizon is thought to be of Pleistocene age. It is called in this paper the lower San Pedro series. The maximum thickness of this particular horizon, so far seen, does not exceed fifty feet.
After the lower San Pedro there was a period of shallow water, lagoon and dune conditions prevalent along this part of the coast, during which the conglomerates of Deadman Island, San Pedro and Los Cerritos were laid down, and the sandy forma- tions in the bluffs one-half mile north of San Pedro and along the Long Beach water front were dejiosited. This period was one of rapidly changing conditions, as is shown by sand-dune deposits and by the nearly horizontal aqueous deposits of both tine sand and gravels in alternating beds. These beds dip gently away from the centers of uplift, and many of the strata are very fossiliferous. This series of strata is called the upper San Pedro series. The maximum thickness of the strata of this horizon is over fifty feet, as is shown by the exposure in the sea-cliff southeast of Long Beach.
Overlying all these deposits is the alluvial soil, varying in depth from two to ten feet, mostly adobe, and filled in some places, notably along the San Pedro bluffs and Deadman Island, with the shells of edible mollusks. These refuse heaps, or ancient kitchen-middens, are abundant on this part of the coast.
ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDRO .
13
Correlation Table of the Marine Pliocene and Pleistocene of California.
(Dotted lines indicate conformable strata; full lines, nonconformable.)
|
*id |
|
|
15 |
(S |
|
o a |
o |
|
a |
a 0 |
|
a |
|
|
oo |
|
|
o |
|
i-d 2
Pliocene
Pleistocene
Merced Series
Sau Diego Formatiou Lower . Upper
Lower
San Pedro Series
Upper
San Diego well 150'
Euss
School
50'
Pacific Beach
(lower horizon)
180'+
Pac. Beach
(Upper
horizou)
20'±
Fool of 26th St. 20'
Spanish Bight 20'
Dead man
Island
45'
BIO
Deadman
Island
12'
Timm's Point 50'
San Pedro
Bluffs
50'
Los Cerritos 50'+
Pacific Beach 15'
Deadman Island 10'
Lumber yard 20'
Crawfish George's 3'
Los Cerritos 20'
Long Beach 50'
Dead.
}uau Is.
4'
Epoch
1^ o so
>
O "
o
o
*Ti
+
Old irrigating ditch
(?)
Old irrigating ditch 1000'+
Barlow's Ranch 100'+
g B
■= a
O CD
2
■Ro c
Packard's
Hill
200'+
Bluff at
bath house
30'
Bluff i mile west of
bath house
25'
Bluff 2 miles east of
wharf
30'
>
m > a
3 W
o >
z w
. a
>
to
>
»ti
oo gg. + P +§
td
Lake Merced to Mussel Rock
below "upper gastropod bed."
5000'+
"Upper gas
tropod bed" to
uucouform-
ity. 150'+
"Terrace formation."
Soft sediments above
uucouformitv.
200'+
San Juan CaiJistrauo
Newpoi't, Orange County.
Port Los
Angeles, fos-
siliferous bed
50'+
Bell Station,
Los Angeles County
1320'
Port Los Angeles,
upper soft strata
150'+
W
San Pablo Bay, oyster beds
c >.
!^
CDS
3 ^
o to
o
X
t-l
o
14 califoenia academy of sciences.
3. Pliocene.
Deadman Island. — Overlying the Miocene shale of Deadnian Island (see diagram B, PI. XXII) is a deposit of brown, clayey sandstone, varying in thick- ness from twenty to forty-five feet. The distinct .strata of this formation will be described in detail. The surface of jointed shale on which the sandstone rests is worn and uneven, but the contact conforms nearly to the dip of the shale, which is between 20° and 30" northea.st. Other evidence beside the worn condition of the shales at the contact goes to show that the erosion took place while the shales formed the sea bottom near the shore. Worm borings are common, and in one place a pholas hole was found in the shale. The contact stratum, which is only about a foot thick, is composed almost wholly of beach-worn pebbles of the Miocene shale, all containing to some extent holes of worms and mollusks. It contains also many well preserved shells and shell fragments. All of the fossils common in this layer are found in the sandstone just above it, so its fauna will be taken up with that of the overlying sandstone in a later part of this paper.
This bottom Pliocene layer dips northeast at an angle of about 25°. Towards the top of the formation the bedding planes become more nearly horizontal, those at the top having a dip of only 8° or 10°. This could be accounted for in one of two ways — either the lowest layer was deposited horizontally and then during the deposi- tion of the subsequent layers there was a gradual uplift toward the southwest, or else the lowest layer was deposited on a sloping bottom, and the general tendency of sediments to settle in the lower portions of their basins and to form horizontal beds gradually overcame the dip.
About eight feet of fine, brownish yellow, clayey sand rests on the pebbly low- est Pliocene stratum. In some of the places exposed to the action of the sea-water this second Pliocene stratum consists of bluish gray clay, and in some places is filled with well preserved fossils. In the southwest corner of the island the second layer is a hard, fine, brown sandstone containing only a few fossils.
Overlying the second stratum is a fine, dark brown sandstone about four feet thick. The most fossiliferous places are hard, but porous. The fossils in these hard places are well preserved, while those in the softer parts of the layer, which is lighter colored, are poorly preserved and fragile. Pieces of the hard portions of the Plio- cene stratum have broken off and have fallen amono; the frascments of shale along the beach. This has caused some people to report the fossils found in this Pliocene bed as occurring in the Miocene shale. On account of the great abundance of lliijasira fOryptodonJ bisecta in this stratum it has been given the local name of "Cryptodon bed." Lucina acutilineata is also very common in the Cryptodon stratum.
Above this very fossiliferous stratum is a bed of brown sandstone from twenty- five to thirty-five feet in thickness, only slightly laminated, and varying somewhat in structure and appearance in different parts of the layer. The lower part is uni- formly soft, while toward the top the color is lighter and the rock much harder. Only a few fossils, such as Lucina acutilineata and Pecten caurinus, have been found in the upper brown sandstone stratum. The total thickness of the Pliocene beds at Deadman Island is about forty-five feet.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
15
List of Species Found in the Pliocene of Deadman Island.
(P indicates species living at San Pedro ; N indicates species found living only noi-th of San Pedro; E indicates extinct species or those not known as living.)
Callhia siihdiaphana, I* Ghama pclliicida, P Corhula tiUcola^ P CumiiKi'm californica, I Kellia lapcrousii, P Leda taphria, P Lucina actitilineala, V Lucina californicu, P Ljjonsia caUfornka, P Macoma inquinala, P
Acmaa insessa, P Amphissa corriu/ata, P Bc'la fidicula, N Bittium anperum, P Calliostoma ranaliculaium, P Calliosloma tricolor, P Cerithidea californica, P Chlorostoma hruniieiim, P Chlorosloma moniereyi, P Chrysodomus sp. indet., N Chrysodomus reclirostris, N Chrysodomus tabulalus, P. Clathurelta conracliana, E Ooliimbella gausapata, P Coliimbella var. carincUa, P Conus cali/ornicus, P Cryplochilon stelleri, N DriUia merriami, E Drillia torosa, P
PELECYPODA. Mylilimeria nuitalli, P Nuciila caslrcnsis, P Panomya ampla, N Panopea generosa, P Pecten caurinus, N Pecten hastatus, P Pcelen hericeus, N Pecten jordani, E Pecten slcarnsii, E
GASTROPODA.
Fusus barharensis, E Hipponyx antiqualus, P Littorina planaxis, P Mangilia sculplurata, P Na^sa californiuna, P Nassa fossa la, P Nassa mendica, P Nassa var. cooperi, P Nasscc perpiiiguis, P Natica clausa, N Neverita recluziana, P Ocinebra interfossa, P Olivella biplicala, P Olioella intorta, P Olivella pedroana, P Pleurotoma bartschi, E Pleurotoma dalli, E Pleurotoma perversa, P Pleurotoma nnaudi, E
P/iolndidea penita, P Protorardia c.entifilosa, P Solett sicarius, P Thracia trapczoides, E Thyasira bisecta, N Thyasira gouldii, P Venericardia barbarensis, P Venericardia venlricosa, N FejiMS similtima, P
Pleurotoma smithi, E Prime oregonensis, P Puncturella cucullata, N Puncturtlla galeata, N Scala indianorum, P Solariella cidaris, P Solariella peramabilis, P Taranus strong!, E Terehra simplex, P Thalotia caffea, P Tornatina eximia, P Trophon gracilis, P Tropihon scalariformis, N Trophon stuarti, N Trophon var. precursor, ] Trophon tenuisculpta, E Turritclla cooperi, P Turritella jewetti, E
Bryozoan remains,
BRACHIOPODA.
Laqucus jeffreysi, N
Tercbratalia smithi.
Resume.
Total number of species 87
Pelecypoda, species 28
Gastropoda, species 56
Brachiopoda, species 2
Biyozoa, species ?
Species now living at San Pedro 55
Percentage of the whole fauna 63.1
Species living only north of San Pedro 16
Percentage of the whole fauna 18.5
Species living only south of San Pedro 0
Percentage of the whole fauna 0
Species extinct or not known as living 15
Percentage of the whole fauna 17.3
Species of questionable habitat 1
Percentage of the whole fauna 1.2
16 (JALIFOKNIA ACADEMY OF SCIENCES.
The fauna of the San Pedro Pliocene is a decidedly northern or boreal one in the sense that many of the species found in the San Pedro Pliocene are living now only in the colder waters far to the north of San Pedro. The large percentage of the living species found now living only north of San Pedro shows this; and in addition, the species in this fauna still living at San Pedro are neai'ly all of a northern or boreal type. No characteristic southern species are found in this fauna.
The evidence shows that the climate in the vicinity of San Pedro during that part of the Pliocene epoch in which these beds were deposited was probably different from the present one. A boreal fauna deposited in comparatively shallow water near the shore implies a boreal climate, at least in proximity to the coast; the fauna contains so many shallow water species, and the lithologic evidence showing that the deposits containing the fauna were laid down near the shore is so strong, that it cannot be regarded as a deep-water temperate fauna. The evidence, then, shows that during upper Pliocene times the climate of this part of Southern California was colder than at present; and if this was true of southern California, it seems reasonable to infer that the colder climate affected the whole coast from San Pedro northward.
There are several reasons for calling the lower sandstone strata of Deadman Island Pliocene. In the first place, 17.3 per cent, of the fauna of these strata are extinct at the present time. This is conclusive evidence that the beds are not Pleistocene, but are of an earlier epoch. They are overlain unconforraably by strata of Pleistocene age, which implies that there was a period of denudation between the epoch of the deposition of the lower beds and the Pleistocene. Besides, these strata rest unconformably upon the Miocene shales. That the Deadman Island Pliocene beds are of upper Pliocene origin is shown by the fact that their fauna gradually grades into the living fauna of San Pedro through that of the overlying Pleistocene beds. The gap between the faunas of the Deadman Island Pliocene and the overlying Pleistocene beds, though distinct, is not wide.
In his correlation paper on the Neocene, Dr. Dall says:' "It appears that on Deadman Island near Point Fermin at least three distinguishable strata appear, the uppermost of which is certainly Pleistocene, while the others are Neocene and the middle layer probably Pliocene." The middle layer referred to is the brown sand- stone which rests on the Miocene shales.
The Deadman Island Pliocene beds are lithologically and faunally similar to the Pliocene beds at San Diego, and have been correlated with them by Dr. Dall.^ In the same table he places the San Diego beds below the Merced series. This does not accord with the evidence offered by the San Pedro Pliocene strata. The San Pedro beds are very near the top of the Pliocene, and have a northern fauna; the relative position of the Merced series is uncertain, and it has a fauna containing such southern forms as Area and Dosinia, with an echinoderm, Scntella interlineata, which has never been found in either the San Diego or San Pedro formations, or in any formation overlying the Merced series. The Merced series has been subject to
> Correlation Papers, Neocene. By W. H. Dall and G. D. HarriB. Bull. U. 8. Geol. Sur., No. 81, 1892, p. 216. -' North Aujerican Tertiary Horizons. By W. H. Dall. 18tb Ann. Eep. U. 8. Geol. Sur., Part II, 1898, p. 336.
ARNOLD— THE PALEONTOLOGY AND STRATlGEAPHY OF SAN PEDRO. 17
much more contortion than either the Deadman Island or San Diego Pliocene. The Pliocene age of the Merced series is unquestioned, and it has too great a vertical development to allow of its coming between the Pleistocene and the Dead- man Island formation, which is at or near the top of the Pliocene. In the light of this evidence, it is the writer's opinion that the Deadman Island and San Diego Pliocene are above the greater irAvt of the Merced series.
2'imm's Puint. — The Pliocene is also exposed at Timm's Point (see diagram D, pi. XXII), where it is similar in every respect to the Deadman Island Plio- cene, except that the layers are not so distinctly separated as at Deadman Island, and, as a whole, the rocks are not so hard as at the latter place. The Miocene shales at Timm's Point dip northeast at an angle of about 25°; and resting on them in the same relative position as at Deadman Island, is the Pliocene sandstone. The Pliocene is also visible in the railroad cut in the bluflf in the southeastern part of San Pedro, where there is a stratum containing numerous specimens of Thracia trapezoidea. The beds along this cut dip gently in a northerly direction, and are ovei'lain in the cut and to the north of it by the lighter colored Pleistocene sands.
The following species were found in the Pliocene deposits at Timm's Point and in the northward continuation of the same strata in the railroad cut and grade:
List of Species Found in the Pliocene at Timm's Point.
pelecypoda.
Callista subdiaphana Pecteii jordani Thracia trapezoides
Leda taphria Protocardia cenlifilosa Thyasira gouldii
Lucina acutilineala Solen sicarius Venericardia hurbarensis
Nucula castrensis I'hyasira bisecla Venericardia ventricosa
Pectcn caurinus
GASTROPODA.
Biltium asperum DriUia torosa Natica clausa
Chrysodomus tabulatus Fusus barbarensis Olivella biplicata
Columbella rjausapata Nassa mendica Terebra simplex
Columbella var. carinala N^assa cooperi Trophon sluarli
Conus californicus Nassa perpinguis Turriiella cooperi
This fauna contains a total of twenty-eight species, of which thirteen are pelecypods and fifteen are gastropods. The fauna, so far as known, is small, not because the beds at that place are barren of fossils, but because little collecting has been done there. The beds are nearly covered with detritus, so that fossils are not easily obtained.
An outcrop of rather hard, fine grained sandstone on the coast about three and one-half miles east of Long Beach has some of the lithologic characters of the Deadman Island Pliocene beds. Although a few fragments of shells were seen in it, no recognizable fossils were obtained from this outcrop, and no definite correlation will therefore be attempted. It may be only a local hardening of the upper San Pedro strata.
4. Pleistocene.
llie Snn Pedro Series. — From the evidence brought forward in this paper it appears probable that most of the Pleistocene, as developed on the coast of California,
( 31 September 23, l'J02.
18
CALIFORNIA ACADEMY OF SCIENCES.
is represented by the strata of San Pedro and Deadman Island. The writer, there- fore, proposes the name San Pedro Series for the series of Pleistocene strata at San Pedro, including the lower and upper formations, as described in the present paper. Lower San Pedro Series. — A stratum of gray sandstone rests unconformably on the brown Pliocene sandstone of Deadman Island. (See diagram B, PI. XXII.) In some places the sand is soft; in others it has been cemented until it is very hard. The soft parts are not fossiliferous, as a rule, while the hard parts are made up in some places almost wholly of beautifully preserved fossils. One locality in particular on the west side of the island, near the north end, is filled with finely preserved specimens. Parts of this bed are very hard, making it almost impossible to get the shells out, while other parts are so soft that the shells can be removed from the matrix with the fingers. This stratum varies in thickness from four to ten feet on the west side to nearly twenty feet on the east side of the island. There seems to be little indication of bedding planes in this stratum. The general dip is to the north. On account of its lying unconformably on the Pliocene, being of different lithological composition, and containing a fauna of which a great number of species have never been found in the Pliocene, this horizon is designated in the present paper as the lower San Pedro series, or the lower part of the Pleistocene. The following species have been obtained from the lower San Pedro gray sand stratum of Deadman Island:
List of the Fossils of the Lower San Pedro Beds (Lower Pleistocene) of
Deadman Island.
(P indicates species living at San Pedro; N indicates species living only north of San Pedro; S indi- cates species living only south of San Pedro; E indicates extinct species or those not known as living.)
Anffulus buttoni, P Anomia lampe, P Bornia relifcra, N Callisla var. pedroana, E Cardium cordis, N Cardi'im procerum, S Chama pellucida, P Clidiophora punclala, P C'ooperella subdiaphana, V C'orbula luteola, P Cryjjlomya californica, P Ciiminyia californica, P Diplodonta orbclla, P Donax californica, P Donax Ufvigata, P Kellia laperousii, P KMia siiborbicularis, P Kennc.rlia bicarinata, N Kennirliajilosa, N Laivicardium subslriatum, ] Lazaria suhipiadrata, P Ledafonsa, N Leda hamata, P Leda var. prcecnrxor, N Leda taphria, P
PELECYPODA.
Lima dehiscens, P Lucina aculilincala, P Lucina californica, P Lucina nutlalli, P l^yonsia californica, P Macoma calcarea, N Macoma inquinata, P Macoma nasuta, P Macoma secla, P Macoma yoldiformis, ] Mactra falcata, P Metis alia, P Modiola fornicata, N Modiola recta, P Moerella salmonea, N Mi/tilus edulis, P Mi/lilimeria nutlalli, Ir Neiera pectinata, P Nucida caatrensis, P Nucula suprastriata, I Oslrea lurida, P Panopca generosa, P Pecten caurinus, N Peclen haslatus, P Pecten hcriceus, N
Pecten var. strategus, N Pecten jordani, E Pecten latiauritus, P Pecten var. monotimeris, I Petricola carditoides, P Petricola denticulata, S Protocardia centifilosa, P Psephis salmonea, N Pscphis tanlilla, N Racta midulata, P Saxidomus aratns, P Semele var. montereiji, N Septifer hifurcatus, P Siliqua lucida, P Solen rosaccus, P Solen sicarius, P Tapes siaminea, P Tellina bodegensis, P Tivela crassatelloides, P Venericardia barbarensis, Venericardia vcntricosa, J> Ve7ms simillima, P Verticordia novemcoslata, Yoldia scissrtrala, P
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
19
Acmoia insessa, P Acmcea pella, P Acmaa spectrum, P Acti^on punctocrelata, P Admeti' gracilior, E Amphissa corrugata, P Amphissa venlricosa, E Amphissa versicolor, P Bela_/!dicitla, N Bela sanctae-monicce, E Biltium asperum, P Bittium caU/ortiician, E Biltium filosum, N Bittium quadrijilatum, P Bittium rugatum, P Ccecum californicum, P Ccecum crehricinctum, P Ccecum m.agnum, ? Calliostoma canaliculatum, P Calliostoma costatum, P Cerithidea californica, P Chlorostoma funebrale , P Chlorostoma var. subapertum P Chlorostoma montereyi, P Chlorostoma var. ligulatum, P Chrysodomus rcctirostris, N Chrysodornus tahulatus, P Clathurella conradiana, E Clipidella bimaculata, N Clipidella callomarginata, P Columbella cali/ortiiana, P Columbella chrysalloidea, P Columbella gausapata, P Columbella var. carinata, P Columbella oldroydi, E Columbella tuberosa, P Conus cali/ornicus, P Crepidula aculeata, P Crepidula adunca, P Crepidula dorsata, P Crepidula navicelloides, P Crepidula onyx, S Crepidula rugosa, P Cryptochiton stelleri, N Cylichna alba, P Cythara branwri, E Diastoma, sp. indet., ? Drillia cancellata, N Drillia hemphilli, S Drillia inermis, P Drillia m.crriami, E Drillia montereyensis, N Drillia var. penicillata, P Drillia torosa, P Eulima falcata, S
Cadulus nitentior, ?
GASTROPODA.
Eulima hantata, S Eulima micatis, P Eupleura muriciformis, S Fissuridea aspera, P Fissuridea murina, P Fissurella volcano, P Fusus barbarensis, E Fusus luteopicius, P Fusus robustus, P Fiisus riigosus, P Galerus mammillaris, P Hipponyx antiqualus, P Hipponyx cranioides, N Hipponyx lumens, P Isapis fenestrata, P Ivara terricula, ? Lacuna compacta, N Lacuna porrecla, N Lacuna solidula, P Lamellaria stearnsii, P Leptothyra bactila, P Leptolhyra carpenter), P Leptothyra paucicostata, N Littorina planaxis, P Littorina scutulata, P Mangilia angulata, N Mangilia var. pedroana, E Mangilia interlirala, P Mangilia oldroydi, E Mangilia painei, E Margarita var. nodosus, P Margarita var. pedroana, P Marginella jewetti, P Melampus olivaccus, P Mitramorpha Jilosa, P Mitramorpha intermedia, E Monoceros engonatum, P Murex festivus, P Nassa californiana, P Nassafossata, P iVassa mendica, P Nassa var. cooperi, P Nassa perpinguis, P Nassa tegula, P Natica clausa, N Neverita recluziana, P Ocinebra barbarensis, P Ocinebra interfossa, P Ocinebra var. aspera, N Ocinebra var. cerritensis, E Ocinebra var. munda, N Ocinebra perita, P Ocinebra ponlsoni, P Odoslomia gouldii, P Odostomia var. avellana, N
SCAPHOPODA. Dentalium hexagonum, P Dentalium indianorum, N
Olivella biplicata, P Olivella intorla, P Olivella pedroana, P Phasianella compta, P Pleurotoma barlschi, E Pleurotoma dalli, E Pleurotoma hoovtri, E Pleurotoma pedroana, E Pleurotoma perversa, P Pleurotoma renaudi, E Pleurotoma smithi, E Priene oregonensis, P Puncturella cucullcita, N Puncturclla galeata, N Scala hindsii, P Scala indianorum, P Scala tincta, P .9ei7a assimilata, P Serpulorbis squatnigerus, P Styliferina tenuisculpta, ? Taranis strongi, E Terebra simplex, P Thalotia caffea, P Tornatina cerealis, P Tornatina culcitella, P Triforis adversa, N Tropihon cerritensis, E Trophon gracilis, P Trophon multicostatus, N Trophon pedroana, E Trophon scalari/ormis, N Trophon stuarti, N Trophon var. prcecursor, E Trophon triangulatus, P Turbonilla adleri, E Turbonilla arnoldi, E Turbonilla aurantia, P Turbonilla crebrijilata, P Turbonilla gibbosa, P Turbonilla laminata, P Turbonilla lowei, E Turbonilla muricata, P Turbonilla pentalopha, P Turbonilla similis, P Turbonilla subcuspidata, S 7\irbonilla tmuicula, P Turbonilla torquala, N Turbonilla var. stylina, N Turbonilla tridenta, N Tnrritella cooperi, P Turritella jewetti, E Vermicularia, sp. indet., ? Vitrinella ivilliamsoni, P Volvarina varia, P Volvula cylindrica, P
Dentalium pseudohrxagonum.
20 CALIFORNIA ACADEMY OF SCIENCES.
ECHINOIDEA. Echhiararhniux excentricus, P Strongylocenirotusfraiici/icannx,!' Stronrn/hcenlroluspurpiiratug, P
CKUSTACEA. Cancer breweri, E
Besum^.
Total number of species 247
Pelecj'poda, species 74
Gastropoda, species 165
Scaphopoda, species 4
Echinoidea, species 3
Crustacea, species 1
Species living at San Pedro 158
Percentage of fauna 64
Species living only north of San Pedro 43
Percentage of fauna 17.4
Specimens living only south of San Pedro 8
Percentage of faima 3.2
Species extinct 31
Percentage of fauna 12.5
Species of questionable habitat 7
Percentage of fauna 3
This is also a cold water fauna. Not only is there a large percentage of species which are found living only north of San Pedro at the present time, but of those species in the fauna which are now living at San Pedro, a great manv are northern forms. A few distinctly southern forms are found in the fauna, however, which shows that the cold climatic conditions prevalent along this part of the coast during the upper Pliocene times were beginning to give place to more temperate con- ditions in the eai'ly part of the Pleistocene. The fauna of the lower San Pedro series is a transitional one between the boreal fauna of the Pliocene and the warm water fauna of the upper San Pedro series. The climatic conditions were therefore chang- ing during lower Pleistocene times; and the climate at the end of the period of de- position of the lower San Pedro deposits was much warmer than that at the end of the period of deposition of the Pliocene. The period of denudation between the Pliocene and Pleistocene epochs was one during which the conditions were also changing.
The lower San Pedro deposits are thought by the writer to be.of Pleistocene origin, for several reasons. First, we have a fauna with a low percentage of extinct species. (The high percentage of the list given above is due to the large number of new species and varieties, many of whicli are close to living forms and are probably living, but which have not been reported.) The large number of species found in this fauna which have never been found in beds of known Pliocene origin, and the lack of several of the typical Pliocene species from its fauna, offer two of the strongest arguments in favor of the Pleistocene age of the lower San Pedro series. The state of preservation of the fossils is also an item in favor of their comparatively recent de- position. It is worthy of note that in several cases the original coloration of the shells of lower San Pedro fossils is still preserved. The sands, too, of this formation are always much less oxidized than those of the underlying Pliocene. An unconformity between this formation and the Pliocene also suggests a lapse of time between the two.
AKNOLD— THE PALEONTOLOGY AND STEATIGEAPHY OF SAN PEDKO.
21
Dr. Lawson in discussing the movements that have taken place during late Tertiary and Pleistocene times in the vicinity of San Pedro, says :' "It follows that, while there is a very profound physical break between the Miocene and Pliocene, the marine Pliocene and Pleistocene formations are intimately associated, with no epoch of subaerial denudation between them." The observations of the writer also show this to be true, although in some places there is evidence of local denudation between the Pliocene and Pleistocene. At Deadraan Island, in particular, there is evidence of a period of denudation between the two.
Beds of a fine gray sand, with gentle north dip, rest upon the Pliocene ex- posed along the railroad grade leading up to the cut in the bluff in the southeastern portion of San Pedro. (See diagram D, PI. XXII.) The exact relation between these gray sands and the underlying Pliocene is uncertain, as detritus covers the con- tact along the face of the bluff. But the gray sand beds seem to rest almost conform- ably on the yellow Pliocene deposits, both having a low dip toward the north. One of the layers of gray sand near the top of the bluff north of the railroad grade con- tains a fauna similar to that of the lower San Pedro stratum of Deadman Island. This stratum is exposed in the bluff to the north of the San Pedro valley, and also in two small cuts in the bluff west of the business portion of the town. These gray sand strata were continuous at one time, the San Pedro valley, which cuts them, having been formed by recent erosion.
In the bluff to the north of the valley the fossiliferous lower San Pedro stratum is about forty feet above tide level and dips northward, disappearing under detritus at the mouth of a small ravine about three hundred yards from the southern end of the bluff, but aj^pearing again north of the ravine at the base of the bluff. Under- lying this lower San Pedro bed are gray sandy strata which correspond to the lower part of this same formation soutii of the valley, and which are unfossiliferous, except in a few places. The following fossils have been found in the lower San Pedro beds in the San Pedro bluffs.
List of Fossils of the Lower San Pedro Beds at the San Pedro Bluffs.
Angulus buttoni Anomia lampe Cardium corbis Corbula luteola Cryptomya calij'oi-nka Cumingia caUfornica Donax caUfornica Donax Icevigala Hinnites giganteus Kellia laperousii Kellia suborbicularls Lievicardium substriatum Lazaria subquadrata
PELECYPODA.
Leda var. prcecursor Leda laphria Lucina acutiUneata Lucina caUfornica Lucina nutlaUi Lyonsia caUfornica Macoma nasuia Macoma secta Macoma yoldiformis Maclra falcata MyliUmcria nuttalli N^ucula castrensis
Nucula suprastriata Oslrea lurida Pecten latiauritus Peclen \av. monotimerv Psephis salmonea Psi'phis iantilla Scmele decina Siliqua lucida Solen rosaceus Solen sicarius Tapes staminea TelUna bodegensis
1 Poat-Pliocene Diastrophism of the Coast of Southern California. By A. C. Lawson. Bull. Dept. Geol., Univ. of California Vol. 1, 1893, p. 128.
22
CALIFOENIA ACADEMY OF SCIENCES.
Acmtfa insessa AcUton piinctocielata Bittium Jilosum Biitium quadrijilatum BiUiwm rugatiim Oacum ralifornirum (.'cecum crehricinclum Cacum magnum. Calliostoma canaliculalum Calliostoma costatum Caltiostonia tricolor Cerilhidra californka Chlorostoma futiebrale Chlorostoma var. suhapertum Chlorostoma var. ligulatum ChryKodomus labulalus (-'lalhurella conradiana Clipidella himaculata Clipidella callomarginata Columbella californiana Columbella chrysalloidea Columbella gausapata Columbella var. rarlnaia Columbella tiiberosa Conus cali/ornicus Crepidula aculeata Crepidula adunca Crepidula navicelloides Crepidula onyx Crucibulum spinosum Drillia hemphilll Drillia var. penicillata Drillia torosa
GASTROPODA.
Eulima micans Fissuridea aspera Fissurella volcano Galerus mammillaris Hipponyx cranioides Hipponyx iumciis Isapis fenestrata Lacuna porrecla Leptothyra carpenteri Liltorina planaxis Liitorina scutulata Mangilia angulata Margarita var. knechti Margarita var. nodosus Margarita var. pedroana Marginella jewctti Melampus olivaceus Mitra maura Monoccros engonatum Nassa fossata Nassa m,endica Nassa var. cooperi Nassa perpinguis Nassa tegula Neveriia recluziana Ocinebra barbarensis Ocintbra inter/ossa Ocinebra var. aspera Ocinebra var. cerritensis Ocinebra poulsoni Odostomia gouldii Odostomia tenuis Olivclla biplicata
Olivetla intorta Olivella pedroana Pachypoma inaijuale Paludestrina curta Paludestrina stolcesi Phasianella compta Physa heteroslropha Planorhis tiimidus Planorbis vermicularis Pleuroloma perversa Scala crebricostata Scala hindsii Scala indianorum Scala tincta
Srrpulorbis sijuamigerus Taranis slrongi Tercbra simplex Tornatina cerealis Tornatina culcitella Trophon pedroana TurboniUa aurantia Turbonilla crebrifilala TurboniUa laminata Turbonilla lowei Turbonilla muricata Turbonilla similis Turbonilla stearnsii Turbonilla subcuspidata Turbonilla lenuicula Turbonilla var. stylina Turbonilla tridenta Turrilella cooperi Volvarina varia
SCAPHOPODA. Dinlalinm hexagonum Dentalium indianorum
CRUSTACEA. Balanus concavus
ECHINOIDEA.
Echinarachnius excentricus
This fauna comprises one hundred and forty species, of which thirty-seven are pelecypods, ninety-nine are gastropods, two are scaphopods, one is a crustacean, and one an echinoderm. The fauna of the lower beds of the San Pedro bhiflfs approaches a little nearer that of the upper San Pedro series than does the fauna of the same formation on Dead man Island. This may mean that part of the lower San Pedro beds was removed from the Deadman Island deposit before the deposition of the upper Pleistocene strata.
The following species occur in the lower San Pedro deposits of the San Pedro bluflfs which have not been reported from the same horizon of Deadman Island:
AKNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDKO.
23
List of Fossils fkom the Lower San Pedro Beds of the San Pedro Bluffs not
FOUND at DeADMAN IsLAND.
(P indicates species living at San Pedro ; N indicates species living only north of Sau Pedro ; S indicates species living only south of Sau Pedro ; E indicates extinct species, or species not known as living.
Calliostoma tricolor, P Crucibulum spinosum, I Margarita var. knechti, Odostomia tenuis, P
PELECYPODA. Hinniles giijanleus, P
GASTROPODA. Pachypoma inaquale, P Paludi strina citrta, E Paludestrina stokesi, E Physa heterostropha, P
Semele dccisa, P
Planorbis tumidus, S Planorbis vermicularis, Scala crebricostata, P Turbonilla stearnsii, S
Upper San Pedro Series. — Kesting on tlie gray sandstone of the lower San Pedro series at Deadraan Island is a stratum of fossiliferous gravel hardened by calca- reous cement. (See Diagram B, PI. XXII.) This stratum, which extends over the whole island at about six feet below the surface, is from two to three feet in thickness. The matrix varies from fine sand to water-worn pebbles of Miocene shale, many of which are full of pholas holes still containing the shell. The fossils are well pre- served, and, in all but a few localities of exceptional hardness, may be removed from the matrix witli the fingers. This stratum lies nearly horizontal. Water-worn boulders of the gray lower San Pedro sandstone occur in the upper San Pedro conglomerate at Deadman Island. This evidence indicates an unconformity between the lower and upper San Pedro series. Similar evidence is noticeable in the bluff north of the San Pedro vallev.
List of Fossils from the Upper San Pedro Gravel Stratum, Deadman Island.
Angulus buttoni Cardium corbis Chama pellucida Cryplomya californica Cumingia californica Donax Icevigata Glycymeris barbarensis Glycymeris septnitrionalis Hinnites giganteus LcEvicardium substrialtini Leda taphria Lucina acutilineata Lucina californica Lucina nuttalli Lyonsia californica Macoma inquinata
AcmcBa inscsna Acmoia spectrum Amphissa versicolor Bitlium quadrif latum Bittium rugatum Bulla punctulata
PELECYPODA.
Macoma nasuta Macoma secta Mactra catilliformis Mactra falcata Metis alia Modiola recta Mytilus cdulis Panopea gcnerosa Pecten latiauritus Pecten var. monotlmeris Pecten subnodosus Pecten ventricosus Periploma argentaria Petricola carditoides Pholadidea penita Plalyodon cancellalus
GASTROPODA.
Calliostoma canaliculatum Cerithidca californica Chlorostoma brunneum Chlorostoma funebrale Chlorostoma var. subaperlnm Chlorostoma gallina
Pododesmus macroschisma Psephis tantilla Pu2)ellaria lamellifera Saxidomus aratus Semele decisa Solen rosaceus Solen sicarius Tagelus californianus Tapes staminea Tapes tcnerrima Tellina bodegensis Tivela crassatelloides Tre.sus nuttalli Venus simillima Venus succincta Zirphma gabbi
Chlorostoma montereyi Chlorostoma var. ligulalum Columbclla ga usapata Columbella var. carinata Columhella tuberosa Conus californicus
24
CALIFORNIA ACADEMY OF SCIENCES.
Crepidula adunca Crepidula grandis Crepidula navicelloidtx Crepidula onyx Crepidula riujosa Crucibulum spinosum Cypreea spadicea Drillia var. penicillala Driliia iorosa Eupleura muriciformis Fissuridea aspera Fissuridea incequalis Fissuridea niurina Fissurella volcano Fusus barbarensis Fhtsus lutcopiclus Fusus robustus Haliolis fulrje.ns Hipponyx cranioides Hiyiponyx lumens Isapis fencstrata Lacuna porrecla
Ocinebra poulsoni Olivella biplicala Olivclla intorta Olivella pedroana Pisania fortis Pleurotoma carpenteriana Pleurotoma perversa Priene oregonensis Purpura crispata Ranella californica Hcala crebricostata Scala hindsii Scala indianorum Scala lincla
Serpulorbis squamigerus Spiroglyphus liluella Terebra simplex Tornalina culcitclla Turrilella cooperi Turrilella jeivetli Volvnrinn varin
Litlorina scutulata Margarita var. pedroana Marginella jewelti Melampus oiivaceus Mitra maura Monoceros engonaium Murex feslivus Murex trialatus Nassa californiana Nassa fossata Nassa mendica Nassa var. cooperi Nassa perpinguis Nassa tegula Natica leimsii Neverila recluziana Norrisia norrisii Ocinebra interfossa Ocinebra Iceepi Ocinebra var. aspera Ocinebra perita
CEUSTACEA. Balanus concavus
ECHINOIDEA.
Echinarachnius exeentricus
SCAPHOPODA.
Dentaliuin semipolituin. Denialium hexagonum
This fauna comprises one hundred and thirty-four species, of which forty- eight are pelecypods, eighty-two are gastropods, two are scaphopods, one is a crusta- cean, and one is an echinoderm. This fauna is not as large as that of the upper San Pedro series at the north end of the San Pedro bhiff, so the discussion of the faana will follow the list of species obtained from the latter locality.
There is a railroad cut a few feet in depth near the southwestern limit of the San Pedro terrace. (See I), diagram U, PI. XXIII.) On both sides of this cut there is exposed a bed of gravel consisting of sand, numerous well preserved fossils, and water-worn pebbles of Miocene shale, many of which are full of pholas holes. The bed is from two to three feet thick, and rests unconformably on the upturned edges of the Miocene shale, which at this point dips northeast at an angle of about 15°. The gravel stratum dips gently toward the south, and is overlain by soil, which varies from three to five feet in thickiiess, growing thicker toward the south. This layer is also exposed at the top of the sea-cliff near D, and at many places along the top of the cliff from D to Timm's Point. This formation is exceptionally well de- veloped on the sides of the ravine which cuts the bluff at Crawfish George's, showing a thickness of three feet, very fossiliferous, and, in some places, hardened by calcare- ous cement. The deposit at Crawfish George's is mentioned by Ashley,^ who refers it to the Pliocene.
1 Neoceue of the Santa Oniz Mountains. By Geo. H. Ashley. Proc. Cal, Acad. Sci., 2nd Ser., Vol. V, 1894, p. 341.
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDKO.
25
List of Fossils Collected at Crawfish George's.
Angulus biMoni Anomia lainpc Oardium corbis Chania pelluckla Cryptomya cali/oniiea Cum'mgia californica Diplodonta orbe.lla Donax Icevigala Glycymeris barbarensis Glycymeris seplenirionalis Lcevicardhtm siibstrialum Lazaria subquadrata Leda taphria Lucina acuiilinenfa Lucina cali/oniica Lucina nullaUi
Acmcea depicta Acmcea hisnssa Acm(Ba histabilis Acmcea mitra Acmcea paUacea Amphissa corrui/atn Amphlssa versicolor Bela fidicula Bittiuni aspe.rum Bittium filosum Billium quadrifilalum Bittium rucjatnm Bulla punctidcUa Ccecum crebricinctum Oalliostoma canaliculalum Calliostoma costatum Calliostoma gcmmulalum Calliostoma tricolor Certhidea californica Ghlorostomci hrunneum Chloroslomci funebrale Chlorostoma var. subaprrtum Chlorosioma cjallina Chlorostoma montereyi Chlorostoma ligulatum Chorus belcheri Chrysodomus rcctirostris Glijuidella callomarginata Columbrlla gausapata Columbella var. carinata Columbella tuhcrosa Conus californicus
Denlalium semipolitum (4)
PELECYPODA. Lyonsia californica Macomti iiiijuinata Macomn nctsula Macoma secla Macira catilliformis Maclra falcata Metis alt a Mytilus edulis Oslrea lurida Pecten caurinus Peclen hastatus Pecten latiaurittts Peclen var. monotimeris Pecten venlricosus Periploma argentarici Pctricola cardiloides
GASTROPODA. Crepidtcla dorsata Crepidtila navicelloides Crepidula rugosa Crucibidum spinosum Drillia var. penicillata Drillia torosa Eulima micans Fissuridea aspern Fissuridea murina Fissurella volcano Fusus barbarensis Fusus luteojnctus Fusus rohtstus Oalerus mammillaris Isapis feneslrata Lacuna porrecta Leptothyra carpenteri Litlorina scutulata Mangilia angulata Mangilia var. pedroana Marginclla jcwetti Melampus olivaceus Mitra maura Monoceros engonatmn Murex festivus Murex leeanus Murex trialatus Nassa cerritensis Nassa fossala Nassa mendica Nassa var. cooperi Nassa pcrpincjuis
CRUSTACEA.
Balanus concavus
ECHINOIDEA.
Echiixarachnius excenlricus
SCAPHOPODA.
Dentalium indianorum
Pholadidea penita Plntyodon cancellntus Pododesmus macroschisma Saxidomus aratus Solen rosacevs Solen sicarius Tagelus californianus Tapes staminea Tapes tenerrima Teliina bodegensis Tivela crassalelloides Tresus nuttalli Venericardia barbarensis Venus simillima Venus succincla Zirphaea gabbi
Nassa tegula Naiica lewisii Neverita recluziana Ocinebra interfossa Ocinebra lurida Ocinebra var. aspera Ocinebra var. cerritensis Ocinebra micheli Ocinebra perita Ocinebra poulsoni Olivella biplicata Olivella intoria Olivella pedroana Pachypoma incequale Phorcus pulligo Pleurotoma carpenteriana Pomaulax undosus Priene oregone.nsis Purpura crispaia Ranelta californica Scata indianorum Scala tincta
Serpulorbis sqiiatyiigerus Spiroglyphus lituella Sijihonalia kellcltii Terebra simplex Tornalina culcitella Trophon pedroana Trophon scalariformis Turritclla cooperi Turritella jewetti Voivarina varia
Dentalium hexagonuni
September 24, 1902.
26 CALIFOKNIA ACADEMY OF SCIENCES.
The fauna of Crawfish George's consists of one hundred and fifty-three species, of which forty-eight are pelecypods, one hundred are gastropods, three are scaphopods, one is an echinoderm, and one is a crustacean. It is similar to the upper fauna of the San Pedro bluff, with the exception that it affords a few s^iecies common in the lower San Pedro series that are not found in the upper beds at any other locality. Another noticeable fact is the great preponderance in numbers of gastropods over pelecypods. The fauna seems to be that of a rocky beach.
All along the cliff, from Crawfish George's to Timm's Point, the gravel lies unconformably in disconnected masses on the Miocene shale, and is covered by soil varying in depth from three to ten feet. From Timm's Point to the north along the bluff this formation is not exposed until a point is reached a little north of the rail- way cut. Here the typical gravel of the upper San Pedro series rests unconformably upon the lower San Pedro gray sand, and is overlain by a layer of soil. The upper San Pedro gravel (see diagram D, Plate XXII) again outcrops in the bluff north of the San Pedro Valley, but is covered in this bluff by a sandy stratum between it and the soil. This gravel stratum runs along the bluff near the surface until it reaches a point about two hundred yards north of the valley, where it suddenly dips at an angle of 45° for eight feet, resting all the while on the eroded surface of the lower San Pedro strata. Again changing its dip to normal, it disap- pears under the detritus at the mouth of a short ravine. The unconformable position of the upper gravel on the lower gray sand is very apparent a few yards south of the ravine, where fragments of the lower San Pedro strata are found in the upper gravel. After the deposition of the lower San Pedro beds there came a period of uplift, during which they were eroded; then came a period of depression, during which the upper San Pedro beds were deposited on the eroded surface of the lower series.
A heterogeneous series of strata, composed of alternating beds of sand and gravel, occurs above the gravel stratum at the ravine and to the north of it. These overlying beds dip gently to the north, but the series does not decrease in thickness to the north for the reason that other strata begin near the top of the bluff, and thus make a nearly horizontal surface to the top of the series, which is overlain by soil to the thickness of from two to ten feet. The lower strata along this bluff are of fine sand, fossiliferous in places. Near the top of the bluff, however, the strata are composed of coarse material, a distinct layer of gravel cemented with lime and containing many well preserved fossils forming the top layer. This top stratum first appears at the top of the bluff about one hundred feet south of the ravine. From this point south of the ravine it can be traced north along the bluff near the top, around the north end of the bluff, and back again on the west side of this promontory for several hundred feet. About six feet below the top gravel stratum is another layer rich in fossils. The beds below these last two are sand and gravel deposits of varying composition, nearly all, however, fossiliferous. Some of these lower strata show sand-dune bedding, while others are horizontal. This alter- nation of bedding would indicate a period of alternating conditions of elevation and
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
27
depression during the beginning of the epoch in which the upper San Pedro beds were deposited. The same sequence of strata as in the north end of the bluff occurs across the little valley to the west. The strata extend toward the west, but just how far it is not possible to determine. All the fossils labeled "San Pedro" and "Lum- ber yard " are from the upper San Pedro strata in this locality, and many fine specimens have been obtained during the past few years. A great many shiploads of material have been hauled away from the bluffs as ballast by the coaling vessels docked at the port of San Pedro.
The uppermost gravel stratum of the ujiper San Pedro series appears to be laid down nearly horizontally and almost continuously over the whole of the lower or fifty-foot terrace of San Pedro Hill.
The following species from the type locality of the upper San Pedro series were collected at the north end of the San Pedro bluff, near the lumber yard, one- half mile north of the valley:
List of Fossils from the North End of the San Pedro Bluff.
(P indicates species found living at San Pedro; N indicates species found living only north of San Pedro; S indicates species found living only south of San Pedro; E indicates extinct species or those not known as living.)
Amianlts callosa, P Anijulus hiUloni, P Anomia lampn, P Area labiata, S Asiarte branneri, E Cardium corbis, N Gardium elalum, S Cardium proccrum, S Cardium quadriiicnaritim, Chama exoijyra, P Chama pfllucida, P CUdiophora punctata, P Corbula luteola, P Cryptomya californica, P Cuminriia californica, P Diplodonta orbf.lla, P Diplodonta serricala, S Donax californica, P Donax Irevir/ata, P Glycymi'ris barbarensis, E Olycymeris septcntrionalis, Hinnitcs giganteus, P Lcevicardium subslriatum, Lazaria subqnadrala, P Leda taphria, P Lucina acutilineata, P Lucina californica, P Lucina nuttalli, P Lucina tcnutsculpta, P
Aincta insessa, P Am,CBa pelta, P Amtca spectrum, P
PELECYPODA.
Lyoiisia californica, P Macoma indentata, P Macoma inquinata, P Macoma naxuta, P Macoma var. kelscysi, S Macoma secla, P Maclra californica, P Mactra catilliformis, P Mactra exolrta, S Mactra falcala, P Mactra hemphilli, E Metis aha, P Modiola recta, P Mytilus edulis, P Nucula supraxtriata, N Ostrea lurida, P Panopea gcnerosa, P Pecten dentatus, S Pecten latiauritus, P Pecten var. fragiliK, E Pecten var. monotimeris, Pecten newsomi, E Pecten stibnodosvs, S Pecten ventricosus, P Periploma argentaria, P Petricola carditoidea, P Petricola denliculata, S Pholadidea penila, P
GASTROPODA.
Actai07i punctoccelata, P Actce07> trankii, S Amphissa corrugata, P
Platyodon cancellatus, P Pododesmufi macroschisma, Psammobia cdentula, ? Psephis tantilla, N Sanguinolaria nuttalli, P Saxidomus arat-us, P Semele decisa, P Se.mele pulchra, P Siliqua lucida, P Siliqua var. nuttalli, N Solen roKaceus, P Solen sicarius, P Tagelua californianu.% P Tapes lactneata, P Tapes siaminea, P Tapes lenerrima, P Tellina bodegensis, S Tellina rubescens, S Tivela crassatelloides, P Tresus nuttalli, P Venericardia barbarensis, Venus fiuctifraga, P Venus gnidia, S Venus neglecta, S Venus simillima, P Venus succincta, P Yoldia cooperi, P Zirphcea gabbi, E
Amphissa versicolor, P Bittiuni asperum, P Bittinm /ilosum, P
28
CALIFORNIA ACADEMY OF SCIENCES.
BMiuni quadrifilatum, P Bittium rugaium, P Bitlium williamno7u, ? Bulla punctulala, S Bulla quoyi, P Caecum cali/orniciitn, P Cacum crebricinclum, P C'alliostonia annulalum, P Calliotiio77ia ca7ialiculafu)n, P C'allios(o77ia costah(7/i, P C'alUontoma yi:m77iutalU7n, P Calliosloma tricolor, P Cancfllaria cooperi, P Cancellaria craw/ordiana, P Cancellaria trilonidea, E Cerithide.a catifor/iica, P ChlorostoTTia aurcoliiicliini, P Chloroiit077ia Jutifbrale, P ChloroM077ia var. subapurlum, P C'hlorosi07>ia galllna, P Chlorostoma mo7Uereyi, P Chlorot!l07na var. ligidat^nn, P Chorus belcherl, P ClathurMa co7iradiana, E Clipidella hhnaculata, N Clipidelta callo7>iargi7iala, P Colu77ibella chrysalloidea, P Columbella gausapata, P Columbella var. carinala, P Columbella minima, E CohimJiella var. prcectirsor, S Columbella hiberosa, P Co7ius cali/or/iicus, P CoralUophila 7iux, S Crepidula aculeaia, P Crepidula adunca, P Crepidula Tiavicelloides, P Crepidula onyx, S Crepidula rugosa, P Crucibulum spiiwsum, P Cylichna alba, P Drillia hemphilli, S Drillia iiier7)iis, P Drillia johnso7ii, E Drillia var. pP7iicillala, P Drillia pudica, S Drillia torosa, P Erato colum,bclla, P JCtUi7)ia ha-^tata, S Eulima 7nicatis, P Eupleura muriciformis, S
Di'iitalium hi'xagoiitim,
Euph'ura var. curia, E Eissuridca asptra, V Fisituridra i7uequalis, S Fissuridea murina, P Fissurella volcano, P Fusus barbarensis, E Fusus luteopictus, P Fusus robustus, P Galerus 7nammillariit, P Hami7iea vircscims, P Helix sp. iudet., ? Isapis fenestrata, P IslmochitOTi regularis, P Lacuna compacta, N Lacu7ia porrecla, N Lacuna nolidula, P Leplothyra carpenteri, P Littorina pla7iaxis, P Littori7ia scutulata P Macron kellettii, S Mopalia ciliata, P MaTigilia hooveri, E Mangilia striosa, P Margarita var. knechti, E Margarita var. pedrocma, E Margi7iell.a jcwetti, P Melampus ollvaceus, P Mitra maura, P Monoceros eiigonatum, P Monoceros lapilloides, P Murex fesiivus, P Murex foliatus, N Murex leea7ius, S Murex 7no7ioceros, S Murex trialatus, P Jfassa californiana, P Nassa cerritensis, E Nassa fossata, P Nassa insculpta, C Nassa 7)iendica, P Nassa var. cooperi, P Nassa perpi7iguls, P Nassa tegula, P Nassa var. hooveri, S Natica lewisii, P Neverita recluziana, P Ocinebrafoveolata, P Ocinebra interfossa, P OciTiebra var. aipera, P Ocinebra ca7icelli7ia, S Ocinebra pe.rila, P
CRUSTACEA. Bala7ms concavus, P
SCAPHOPODA.
Dentaliu77i pseudohexagonu7n. ?
ECHINOIDEA. Eckinarachnius excentricus, P
PISCES.
Urolophus halh'ri, ?
Oci7iehra poulvmi, P Odostomia tenuis, P Olivella biplicata, P Olivella i7itorta, P Olivella pedroa7iii, P Opalia borealis, P Pachypoma iniKjuale, P Paludestrina curia, E Paludestri7ia stokesi, E Phasianella co7npta, P Pisa7iia fortis, E Planorbis tumidus, S Pla7iorbis vermicularis, N Pleurotoma carpenteriana, P Pleurotoma cooperi, E Pleurotoma perversa, N Pleurotoma tryo7iia7ia, P Pomaulax u7idosus, P Prie7ie orego7iensis, P Puncturella cucullata, N Purpura crispata, N Purpura saxicola, P Pyratnidelta var. variegata, S Ranella cali/or/iica, P Bissoa acutelirata, S Scala bellastriata, P Scala crebricostata, P Scala he7nphHli, E Scala hindsii, P Scala indianorum, P Scala tincta, P Se.rpulorbis sejuamigerus, P Sipho7ialia kellettii, P Spiroglyjihus lituella, P Terebra si7nplex, P Tor7iati7ia cerealis, P Tornaii7\a culcitella, P Trivia californica, P Triton gibbosus, S Tro}iho7i multicostatus, N Turbonilla auraniia, P TurboniUa la77iinata, P Turbonilla lowei, E Turbo7iiUa stear7isii, S Tttrbo7iilla subcuspidata, S TurboniUa lenuicula, P Turritella cooperi, P Turritella jetvetti, E Vitrinella willia7nso7ii, P Volvari7ia varia, P
Dentaliu77i se)7iipolitu77i, S
ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 29
Resume.
Total number of species 252
Pelecypoda ^5
Gastropoda 1^1
Scaphopoda ^
Echiuoidea 1
Crustacea 1
Pisces *
Living at San Pedro 1"2
Percentage of fauna 68.2
Living only north of San Pedro 15
Percentage of fauna 6.1
Living only south of San Pedro 36
Percentage of fauna 14.2
Extinct species 24
Percentage of fauna 9.5
Questionable 4
Percentage of fauna 1-6
The fauna of the upper San Pedro series as afforded by the beds near the himber yard is of a character more nearly resembling that found living at the present time on the coast two or three hundred miles further south. Not only is there a large percentage of species now living only south of San Pedro, but of the species living at San Pedro many are southern forms. Several of the northern forms remained during the period of deposition of the upper San Pedro series, but in greatly diminished numbers. Of the extinct forms most are new species or varieties which may be found upon a more extended examination to be living. Faunal evidence leads to the conclusion, therefore, that the climatic conditions on the coast near San Pedro during the period of deposition of the upper San Pedro series were as warm, if not warmer, than those of the present time. The change from the boreal condi- tions of the upper Pliocene epoch to the tropical or semitropical conditions of the Pleistocene was not sudden, but took place rather gradually, as is shown by the transition fauna of the lower San Pedro deposits.
The upper San Pedro stage described in this paper is separated from the lower San Pedro deposits for the following reasons: First, there is an unconformity between these upper beds and the underlying formations at all of the localities examined. Secondly, the upper San Pedro beds differ lithologically from the lower San Pedro strata; the former being largely gravels, while the latter are of gray sand. Thirdly, the difference in the fossils of the two horizons is very marked. Many found in the lower series are not found in the upper, and many of the species in the latter are never found in the former. Fourthly, the upper series has a semi-tropical fauna, while that of the lower series approaches the semi-boreal.
The upper San Pedro beds do not represent the top of the Pleistocene. The fauna of these upper beds, although having many species in common with the living fauna of the same locality, is still quite distinct. This would suggest a period of considerable length since the deposition of the strata. The number of distinctly southern forms living at San Pedro during the period of deposition of the upper beds also shows that there has probably been a change in climatic conditions since
30
CALIFORNIA ACADEMY OF SCIENCES.
that time. A raised beach unconformable with the upper San Pedro strata at Dead- man Island shows that there have been orographic movements since the upper San Pedro beds were deposited. All of this evidence, then, leads to the conclusion that there has been a sufficient lapse of time since the deposition of the upper San Pedro strata, to admit of marked faunal and orographic changes.
The upper San Pedro series is well developed on Los Cerritos Hill, where the typical fossiliferous gravels of the upper San Pedro formation overlie unconformably the brown, tilted sandstones which form the major portion of that hill. A little above H (diagram E, Plate XXIII), the gravel stratum has a dip of 4° due south. Below the gravel stratum is a thin bed of sand, which is also very fossiliferous. At G the gravel stratum is only a few feet below the surface of the hill, but near the top of the hill this stratum is covered by a deeper deposit of sands and sandy soil. The dip of the stratum at K is N. 85° W. at an angle of from 12° to 15°. At K the gravel is overlain by a deposit of fine, unfossiliferous sand four feet thick.
At all the localities on Los Cerritos Hill where the upper San Pedro beds are exposed, the underlying formation is a series of sands and conglomerates. No fossils were obtained in the underlying series of rocks, but they are probably of the lower San Pedro series.
It will be noticed, on looking at the contours on diagram E, Plate XXIII, and observing the dips at the different places, that the dip of the gravel stratum conforms very nearly to the slope of the hill. There is a fault at H, which cuts the upper San Pedro stratum. The sand deposits above the gravels in a few places are probably what is left of layers of sand which once covered the whole area. On the flanks of the hill, both to the northwest, where the Los Angeles Terminal Railway cuts the ridge, and toward the south, where the ocean has exposed the beds, sands overlie or replace the gravel stratum. This fossiliferous upper San Pedro stratum is at no place on Los Cerritos Hill more than a few feet thick. W. S. T. Smith' thinks that per- haps this hill is wave built, but a careful examination shows that it is the result of an orogenic movement which has taken place since the lower San Pedro beds were deposited there. This is shown by the contortion of the lower formation, and by the steep dips of the uppermost layers, which conform almost exactly with the slope of the hill. This orogenic movement has taken place since the upper San Pedro series was deposited, and is evidence in favor of the theory that the upper San Pedro beds are at least older than the latest Pleistocene.
List of Species Collected in the Upper San Pedro Beds at Los Cerritos.
Atigena cerrilensis Amianlis callosa Angulus buttoni Anomia lanipe Aslarte hranntri Cardium corbis
PELECYPODA.
Cardium datum Cardium procerum Cardium quadrigenarium Chama exogi/ra Chnina pellucida Corbula luteola
Crypiomya californica Donax laevigata Qlyrymeris barharensis Glycymeris sppte.ntrionalis Hinniies giganteus Lmvicardium substriatum
' Topographic Study of the Islands of Southern California. By W. 8. T. Smith. Bull. Dept. Oeol., Univ. of Cal., Vol. II, 1900, p. 224.
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDKO.
31
Leila taphria LithophfKjiis jilumula Lucina califoniica Lucina nuttalli Macoma indeniata Macoma inquinnta Mricoma nnsuta Macoma vai". kelsryi Macoma secla Mactra calilliformis Mactra falcala Metis alia Modiola fornicaia Modiola recta Nucula supra.itriata Oslrea lurida
AcnKJ^a insessa Acmaa pelta Amphissa corrugata Amphissa versicolor Bittium ijuadrifilatum Bittium rugatum Bulla punclidata Coecum californicum Ccecum crebricinclum Calliostoma caiialiculatum Calliosloma coslaiuvi Calliostoma gemmulatuni Calliosloma tricolor Cerithidea californica Chlorostoma funebrale Chlorosloma var. subaperlum Chlorostoma var. ligulatum Chorus belcheri Clipidella bimaculata Clipidella callomarginata Coliimbella gausapata Columbella var. carinata Columbella luberosa Conns californicus Crepidula adunca Crepidula dorsata Crepidula navicelloides Crepidula onyx Crepidula rugosa Crucibulum spinosum Drillia cancellata
Panopea generosa Pccten latiauriius Pecten var. fragilis Peclen var. monotimeris Pecten neicsomi Peclen ventricosus Periploma argeniaria Petricola cardiioides Petricola denticulata Pholadidea penita Platijodon cancellatus Psephis tantilla Sanguinolaria nullnlli Saxidomus aratus *
Semele decisa
GASTROPODA.
Drillia hemphilli Drillia inermis Drillia var. ptnicillata Drillia torosa Eulima micans Pissitridea aspcra Fissuridea iiuBqualis Fissuridea murina Fissurella volcano Fusus luteopictus Hipponyx cranioides Lacuna compacta Lacuna porrecta Leplothyra bacula Lillorina scutulata Lucapina crenulata MangiUa angulata Mangilia interlirata MangiUa striosa Margarita var. pedroana Melampus olivaceus Monoceros engonatum Murex festivus Nassa cali/orniana N^assa cerritensis Nassa fossata Nassa mendica Nassa var. cooperi Nassa perpinguis Nassa tegula Natica lewisii
CRUSTACEA.
Balanus concavus
SCAPHOPODA. Dentalium hexagonum
ECHINOIDEA.
Echinarachnius exccnlricus
Semele pulchra Silit/ua liicida Solen sicarius Tagelus californianus Tapes lacineata Tapes ataminea Tapes tenerrima Tt'llina bodegensis Tellina idfi Tivela crassatelloid's Tresus nuttalli Venus neglecta Venus simillima Venus succincta Zirpihcea gabhi
Neverita recluziana Ocinebra var. aspera Ocinebra var. cerritensis Ocinebra poulsoni Olivella biplicata Olivella intorta Olivella pedroana Pleuroloma pierversa Ranella californica Scala hindsii Scala indianorum Scala tincta
Serpulorbis squamigerus Sigaretus debilis Siphonalia kellettii Spiroglyphus litttella Taranis slrongi Terebra simplex Tornatina culcitella Trophon cerritensis Turbonilla aurantia Turbonilla crebrifilata Turbonilla laminata Turbonilla lowei Turbonilla similis Turbonilla stcarnsii Turbonilla subcuspidata Turbonilla ienuicnla Turbonilla tridenta Turritella cooperi Volvaria varia
This fauna consists of one hundred and sixty species, of which sixty-four are pelecypods, ninety-two are gastropods, one is a scaphopod, one is a crustacean, and
32
CALIFOKNIA ACADEMY OF SCIENCES.
one is an echinoderm. It is similar to the upper San Pedro fauna of the beds at the north end of the San Pedro bluff; and has even a more southern character than that fauna. The great preponderance of pelecypods over gastropods as regards the num- ber of individuals is noteworthy in the Los Cerritos deiwsits. It is such a fauna as would be found on a low, sandy coast.
There is an extensive exposure of upper San Pedro strata in the bluff to the south and southeast of Long Beach. A typical section of the bhiff is represented by the section exposed at B (diagram E, Plate XXIII), about one and one-half miles east of the Long Beach wharf. The sequence of the beds is as follows :
Soil, grading into uustratified brown sand 12 feet
Thin beds of light gray sand 8 feet
White wind-bedded sand 15 feet
Brown sand, with horizontal bedding 6 feet
Total thickness 41 feet
All of the strata from this point west to A (diagram E, Plate XXIII), the end of the bluff, dip gently westward, the lower strata disappearing successively under the level of the beach. The fossils in this series occur only in local deposits, most of them being found in lens-shaped pockets in the white sand layer. There is a very fossiliferous deposit at E, which extends for three hundred feet along the base of the cliff. At B (diagram E, Plate XXIII), also, there is a small deposit of sand con- taining only Ostrea lurida. It is probable that for the most part these strata were deposited during a period of sand-dune and estuarine conditions along this part of the coast. The dominating shells in these deposits are Ostrea lurida, CryiAomya califor- nica, Tagelus californianus, and other forms which inhabit lagoons and shallow waters. The following fossils were obtained from the fossiliferous bed at the base of the bluff at E, southeast of Long Beach.
List of Fossils from the Beds Southeast of Long Beach.
Anomia lampe Balanus concavus Crepidula rugoaa Columbella var. cariuala C'ardium procerum Cardium fjnadrigenarhim Crucib II In m spinas u m Chionc simillima Chlorostoma funehrale Cryptomya cali/ornica Conus californicus Donax IcevigcUa Dentalium hexarjonum Drillia var. peniciUala Fissu ridca inierj ualis Olyrymeris seplenlrionalis Lucina ntittalli
The deposits of although no fossils have deposits around the base
Lucina cali/ornica Liitorina scutulata Lunatia lewisii Leda taphria Monoceros engonatum Maconia sccta Macoma nasula Nevcrita reculziana Nassa perpinguis Nassa cerrilensis Nassa tegula Nassa me.ndica Nassa var. coopcri Nassa fossata Nassa californiana Ostrea lurida Olivelta biplicala
Dominguez Hill are probably of been found in them. Lithologically of Los Cerritos Hill.
Olivella pcdroana Olivella intorta Pecten ventricosus Pecten latiatiriltis Pecten var. monotimeris Pleurotoma carpentcriana Pteronotus festivus Serpulorbis squamigrrus Scala tincta Terebra simplex Tagelus californianus Turritella cooperi Tellina bodeginsis Tivela crnssatelloidcs Tapes slaviinra Vcnericardia barbarensis Zirphaia gabbi
upper San Pedro age, they are similar to the
AKNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDRO.
33
Raised Beach Formation. — The recently raised beach on the north end of Deadmau Island (see diagram B, Plate XXII) shows that the period of uplift which followed the deposition of the upper San Pedro beds is not yet finished. This raised beach contains many fossil shells in a perfect state of preservation, all of them retain- ing their original color, which suggests how recently this uplift has taken place.
List of Fossils from the Raised Beach, North End of Deadman Island.
Cryplomija cali/oraica Donax Icevigala Lcevicardhun substriatum Lucina cnlt/ornica Liiclna nntlalli ilacoma inquinala
Acmna spectrum Acmcea pelia Bulla nebulosa Calliostoma canaliculatum Cerithidea californica Chlorostoma funehrale
PELECYPODA.
Macoma nasuta Macoma secla Mactra catilliformis Mactra falcata Mytiius edulis Pecten iatiaurilus
GASTROPODA.
ColumbeUa gausapala ColumbiUa var. carinaia Conns californicus Crepidula rugosa Credbulum spinosum Dr'dlia var. penicillnta
Peclen var. monolimeris Pecten ventricosus Petricola carditoides l^apes staminea Tellina bodegensis
Fissurella volcano Xassa fossata Nassa var. cooperi Olivella biplicata OliveUa intorta
These species are all found living in the waters adjacent to Deadman Island at the present time, and the raised beach specimens are in nearly as good a state of preservation as the living shells.
5. Post-Pleistocene Deposits.
Overlying the Pleistocene of Deadman Island, and all along the San Pedro terrace, is soil containing many shells, in fact, in places; it is made up almost entirely of shells. These are the remains of ancient Indian kitchen-middens. Ashley ^ describes as Quaternary a layer of shells found in the lower terrace of San Pedro Hill. After examining the fossils collected by him, and also visiting the locality from which they came, the writer is convinced that these deposits are simply the shells brought there by the Indians, for the association of species is not such as would be found at any one place on the beach; rocky shore and lagoon shells being found in about equal quantities. At every place where these shell deposits in the soil have been examined by the writer they have been found to contain pieces of charcoal, bones of mammals, and other evidences of refuse heaps. These kitchen-middens are common at many places along the coast. Those at Port Harford are over six feet in thickness and have been mistaken by some collectors for Pleistocene strata.
The shells in these kitchen waste heaps are of a kind that would be used for food, and include such species as Haliotis cracheroidii, Pecten aciuimlcatus, Cliione succincta, Tivela crassatelloides, Tapes staminea, Saxidomus aratus, etc. All of the specimens of Haliotis so far recorded from the Pleistocene, with the exception of one
1 The Neocene Stratigraphy of the Ssuta Cruz Mountains of California. By George H. Ashley. Proc. Cal. Acad. Sci., 2d Ser., Vol. V, 1895. pp. 353-356.
( 5 ) September 25, 1902.
34 CALIFORNIA ACADEMY OF SCIENCES.
Haliotis fulgens found by the writer in the upper San Pedro conglomerate of Dead- man Island, and another in the Pleistocene at Spanish Bight, San Diego, have been taken from these Indian kitchen-middens.
6. Alphabetic List showing the Distribution of Species in the Vicinity
OF San Pedro.
In order to avoid any mistake, a brief description of the locality represented by each column in the following list is here given.
The second column, marked " Deadman Island " under upper San Pedro series, refers to the gravel stratum which extends across Deadman Island about six feet below the surface, and which is shown as the upper San Pedro series in diagram B, PL XXII. (See also diagram U, PI. XXIII.)
The third column, marked " Lumber Yard," refers to the sand and gravel deposits at the north end of the San Pedro bluff; these beds are designated as upper San Pedro series in diagram B, PI. XXII.
The fourth column refers to Los Cerritos Hill, which is shown on diagram E, PI. XXIII, and diagram 0, PI. XXII. The fossils reported in this column come from the gravel and sand strata at the localities H and K on that hill.
The fifth column, designated as "Crawfish George's," refers to the deposits on the northeast side of the mouth of the ravine which empties into the ocean at Crawfish George's. (See diagram E, PL XXIII.)
The sixth column, marked " Deadman Island " under lower San Pedro series, refers to the gray sand deposits lying between the Pliocene and upper San Pedro gravel strata; this deposit is designated as lower San Pedro series in diagram £, PL XXII.
The seventh column, designated as "San Pedro Bluffs," refers to the lower San Pedro strata which lie above the Pliocene on the south and below the upper San Pedro series on the north, in the water front bluff east of San Pedro; these deposits are designated as lower San Pedro series in diagram I), PL XXII.
Column eight, marked " Deadman Island " under Pliocene, refers to the brown san(L "Cryptodon beds," and contact stratum of Deadman Island; these deposits are designated as Pliocene in diagram B, PL XXII.
The ninth column, marked "Timm's Point" under Pliocene, refers to the brown sand deposits of Timm's Point and between that jwint and the middle of the railroad cut and grade up the bluff in the southeastern portion of San Pedro; these deposits are designated as Pliocene in diagram J), PL XXII.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
35
Alphabetic List Showing the Distribution op Species in the Vicinity' of San
Pedro.*
(E indicates species which are extinct; X Indicates species living at San Pedro; S indicates species living only south of San Pedro; N indicates species living only north of San Pedro; C indicates species living only at Catalina Island; R stands for rare; M stands for medium abundant; C stands for common.)
PELECYPODA.
Aligena cerritensis, sp. nov
Amiantis callosa Conkad
Angulus huitoni Dall
A nomia lanipe Gray
Area labiala Sowerbt
Astarie (Crassinella) branneri, sp. nov
Bornia relifera Dall
Callista subdiaphana Cabpentek
Callisia subdiaphana var. pedroann, var. nov.
Callista newcombiana Gabb
Cardium corbis Martyn
Cardium elalmn Sowerby
Cardium procerum Sowerby
Cardium quadrigenarium Conrad
Chama exogyra Conrad
Chama pellucida Sowerby
Clldiophora punctata Conrad
Cooperella subdiaphana Carpenter
Corbula luteola Carpenter
Cryptomya californica Conrad
Cumingia californica Conrad
Diplodonta orbella Gould
Diplodonta serricata Reeve
Donax californica CONRAD
Donax laevigata Desha YRS
Glycymeris barbarensis Conrad
i3
E X X X
s
E N N E X N S S X X X X X X X X X
s
X X
E
Pleistocene.
Upper Sail Pedro.
11
■a rt
R
R R
R
R R
M R
R R
C R
M
R M K C C R R R
R C R R C R C C
R
C R C
M
M R C C R R
M M
C R
tft -
« SI,
fcEf
cu o
R M
M
R
R R R
M R
Lower San Pedro.
T3 rt
M R
R
M
M R R R M R R
R R
R R
M
M M C
R
M
a n
c o
* This list has been kept open until the time for sending the manuscript to presB, and contains a few species vbich are not given in the general discussion, although the descriptiona of all species mentioned are given in Part II
36
CALIFORNIA ACADEMY OF SCIENCES.
|
a > 2 |
Pleistocene. |
Pliocene. |
|||||||
|
Upper San Pedro. |
Lower San Pedro. |
||||||||
|
(13 V P4 |
4 O |
h ■a B |
0 Ph 3 |
i a |
|||||
|
OlycytHCTts septeulTioiialis Midden dorf |
N X X X c N X X N X N X X X X X X X X N X X X s X X X X s X s X N X N X |
R R R R R R c R R M R C M R R R |
c M c C M R R C R R R C C M C M C R C R R R R |
R R R M R R C R C M M R C c c R R |
R R R R R R R M R R M R R R M R R |
R R R R R R M R R c R C C 0 M M M R R R R R R C R |
R R R R R R c c c c M R R |
1 R C C C C M C |
|
|
JCcllici Iciperousii Deshayes. |
|||||||||
|
Kennerlia filosa Carpenter |
|||||||||
|
Lftvicdrditt^n subsirHiiutn Conrad |
|||||||||
|
Ledcc fos<^ct Baird |
|||||||||
|
I/cdct 7niuttict var. pr<ECUTS0T, var. nov |
|||||||||
|
R |
|||||||||
|
C |
|||||||||
|
Z/Uchi(t californictt Conrad |
|||||||||
|
Lyonsia californica Conrad |
|||||||||
|
Macoma indrviata Carpenter |
|||||||||
|
MacoTfia nasutci var. helseyi Dall |
|||||||||
|
Macoma secia Conrad |
|||||||||
|
Macoma yoldiformis Carpenter |
|||||||||
|
Mactra {Spisula) catillifornw Conrad |
|||||||||
|
Maclra exokta Gray |
|||||||||
|
Mactra [Spisula) falcala Gould |
|||||||||
|
Mactra hemphilli Dall |
|||||||||
|
Metis alia Cokrad |
|||||||||
|
Modiola fornicata Carpenter |
|||||||||
|
Modiola recta Conrad |
|||||||||
|
Mrerella salmonea Carpenter |
|||||||||
|
Mytilus edulia lANnmvs |
|||||||||
ARNOLD — THE PALEONTOLOGY AND STEATIGBAPHY OF SAN PEDEO.
o7
Mytilimeria niittalli Conrad
Necera peciinata Carpenter
Nucula {Acila) casirensis Hinds
Nucula siiprasiriata Carpenter
Ostrea liirida Carpenter
Panoniya ampla Ball
Panopea generosa Gould
Pecten (Patinopecten) caurinus GotJLD
Pecien (Pecten) denlatus Sowerby
Pecten (Chlamys) hasiatus Sowerby
Pecten (Chlamys) herkeus Gould
Pecten (Chlamys) hericeus Yar. strategns Dall.. .
Pecten (Chlamys) jordani, sp. nov
Pecien latiauritus Conrad
Pecten latiauritus var . fragilis, Yar. hoy
Pecten latiauritus Yar. monoiimeris Conrad
Pecten (Plagioctenium) newsomi, sp. nov
Pecten stearnsii Dall
Pecien (Nodipecten) subnodosus Sowerby
Pecten (Plagioctenium) ventricosus Sowerby.... Pecten (Plagioctenium) ventricosus Sowerby var.
Periploma argentaria Conrad
Petricola carditoides Conrad
Petricola (Petricolaria) cognata C. B. Adams...
Petricola denliculata Sowerby
Pholadidea penita Conrad
Platyodon cancellatus Conrad
Pododesmus (Moitia) macroschisma Desha yes...
Protocardia centifilosa Carpenter
Psammobia edentula Gabb
Psephis aalmonea Carpenter
Psephis tantilla Gould
Rceta undulata Gould
Rupellaria lamellifera Conrad
Sanguinolaria nuttaUi Conrad
Saxidomus aratus Gould
a u wo
X X X
N X N X N S X N N E X E X E E S X E X X X
s
X X X X
?
c
N X X X X
Pleistocene.
Upper San Pedro.
P
K
M
K
E M
E M E
M B E
|
Lumber Yard. |
J |
|
C |
c |
|
C |
E |
|
E |
|
|
E |
|
|
C |
C |
|
E |
E |
|
E |
M |
|
E |
E |
|
E |
|
|
C |
M |
|
E |
|
|
R |
R |
|
M |
E |
|
E |
|
|
E |
C |
|
M |
M |
|
E |
E |
|
E |
|
|
R |
|
|
E |
E |
|
M |
E |
|
c |
0 |
rt O
E
E
M
M E E
Lower Sau Pedro.
E E R E E E E M
E E E E E
E
R
R
M E
R
R
R R E
E
R
E E
as
R
E E C
M M
M
ga
E
38
CALIFORNIA ACADEMY OF SCIENCES.
Semele decisa Conrad
Semele pulchra Soweeby
Semele pnlchra v&r. monlereyi, var.uov.
0 c
CUTS
a,
X X
N
Septifer bifurcatus Conrad X
Siliijua iiicida CoNRAD
Siliqua patula var. nuttalli Conrad
Solen rosaceus Carpenter X
X
N
Solen sicarius Gould X
Tagelus californianus Conrad X
Tapes laciniata Carpenter X
Tapes staminea Conrad X
Tapes tenerrima Carpenter X
TMina bodegensis Hinds X
Tellina ida Dall X
Tellina rubescetis Hanley S
Thracia Irapezoides Conrad E
Thyasira bisecta Conrad N
Thyasira gouldii Philippi X
Tivela crassatelloides Conrad X
Tresus nuttalli Conrad X
Venericardia barbarensh Stearns X
Venerkardia venlricosa Godld N
Venus (Chione) flucti/raga Sowerby X
Ve.nus (Chione) gnidia Broderip & Sowerby S
Venus (Chione) neglecta Sowerby j S
Venus (Chione) simillima Sowerby t X
X X X X X
Venus (Chione) succincta Valenciennes
Verticordia novemcostala Adams & Reeve.
Yoldia cooperi Gabb
Yoldia scissurata Dall
Zirphoea gabbi Tryon
Pleistocene.
Upper San Pedro.
M
R
R C
C R R
R C
Lower San Pedro.
■25
M C
B
.CO
M R
M R
R C R C R C
C C R
R R R
C C
R
M
C R
M
R C M C R C R
M R
R C C
cd o
S-o
R R
M
M R R
R R R
R
C
M
R R R
R C
M
R R
R
a m to" in
M
M
R
M
M M
R
C R
C C
R
M
C R R
M C
AKNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO.
39
GASTKOPODA.
Acmcea depicta Gould
Acmma insessa Hikds
Acmcea inslabilis Gould
Acmcea mitra Eschscholtz
Acmcea pateacea Gould
Acmcea pelta Eschscholtz
Acmcea spectrum (Nuttall) Keeve
Actceoii ( Rictaxis) punctoccelata Carpenter.
Actceon iraskii Stearns
Admete gracilior Carpenter
Amphissa corrugala Eeeve
Amphissa ventricosa, sp. nov
Amphissa versicolor Dall
Beta fidicula Gould
Bcla sanctce-monica: sp. nov
Bittium asperum Gabb
Bittium californicum Dall & Bartsch
Bittium filosum Gould
Bittium (jvadrijiiatum Carpenter
Bittium rugaitnn Carpenter
Bittium wiUiamsoni, sp. nov
Bulla punctulata A. Adams
Bulla quoyi Gray
Ccecum californicum Dall
Ccecum crebricinctum Carpenter
Ca'cum magnum Stearns
Calliostoma annulatum Martyn
Caltiosloma caniculatum Makiyn
Calliostoma costatum Martyn
Calliostoma gemmulatum Carpenter
Calliostoma tricolor Gabb
Canccllaria cooperi Gabb
Cancellaria craw/orcliana Dall
Cancellaria tritonidca Gabb
3
s
X N X X X X X
9
E X E X
N E X E N X X
V
s
X X X
;
X X X X X X
s
E
Pleistocese.
Upper San Pedro.
5a
K
K
M
E M K R
C R C E C E E E
M M M M M E E E
E
M
E
R
R
C
R E
C E R R
"I
" 9.
E M R C C
C E
E
M C
M
C R R R
Lower San Pedro.
M
E E E
E E E R R E M R M M C
C R R
M R
M
E
M M C
M C E
M R
11
M
E
E
40
CALIFORNIA ACADEMY OF SCIENCES.
Cerithidea californica Haldemann
Chlorosloma aurcoUncium Forbes
Chlorostoma hrunneum Philippi
Chlorostoma funebrale A. Adams
Chlorosloma funrbrale var. subapertum Carpenter..
Chlorostoma (jallina Forbes
Chlorostoma monlerejii Kiener
Chlorostoma (Omphalius) virklulum var. iUjulatum
Menke
Chorus belcheri Hinds
Chrysodomus, sp. indet
Chrysodomus rectirosiris Carpenter
Chrysodomus tahulatus Baird
Clalhitrella conradiana Gabb
Ciypidella bimacjilata Dall
ClypideUa callomaryinata Carpenter
Columhella ( Aslyris) californiana Gaskoin
Columbella (^iBsop«s) chrysalloidea Carpenter.
Columbdla {Aslyris) gausapala Gould
Columbella (Aslyris) gausapala var. carinata Hinds
Columbella {Anachis) minima, sp. uov
Columbella {^Esojnis) oUlroydi, sj). uov
(■oliimbella solidula var. praicursor, var. uov. . . .
Columbella (Aslyris) luberosa Carpenter
Conus californicus Hinds
Coralliojihiia ii ax IvEEVE
Crepidula aeulcala Gmelin
Crepidula adwnca Sowerby
Crepidula dorsala Broderip
Crepidula grandis Middendore
Crepidula navicelloides Nuttall
Crepidula onyx Sowerby
Crepidula rugosa Nottali
Grucibulum spinosum Sowerby
Cryptochilon slclleri Middendore
>
5
X X X X X X X
X X
N N X
9
N X X X X X E E S X X
s
X
X X
N X
s
X X
N
Pleistocene.
upper San Pedro.
an
E K R K K
E
E
C
E
C
M
E
M E C M
3^
c
M
M M E E
M M
E
E E
C E C E
E C C E
C
M
C
c
E
E E
C E
E E
E
C
E
C
M E
E E
C
M
E C C E E
C E
E
E
M
E C
M E
M
0 M
Lower San Pedro.
a
ti
S2
E
E E
E
M M C M E E E E M
E
M M
E
M E
E R E
1.1a S5
M
E E
M
E
E M R M E E M
E M
M
M
M
a .
a
E
E
E
E M
C C
E C
M
a o
H M
U
AKNOLD— THE PALEONTOLOGY AND STEATIGllAPHY OF SAN PEDIIO.
41
|
6 > |
Pleistocene. |
Pliocene. |
|||||||
|
Upper San Pedro. |
Lower San Pedro. |
||||||||
|
n£ la's |
5^ |
in .s St u |
a si TS tSt a |
o u |
s ai |
||||
|
Cylichna alba Brown |
X X E 9 N S X X E E N S X X S S X s E X s X X X X X X X X X 9 ^ ! i N X |
K M K B K R E M R M E R R R |
R R C C C B R R R R R B R R B B C E M B E E E B |
E M C C E M E M E M M E |
R M G E C M C E C C E |
M C E M M E R R R E E R C R R R M B R M R R C R |
B M R M M M R M R |
B C C E |
|
|
Cyprcea spadicea Gray |
|||||||||
|
Diastoma, sp. iiidet |
|||||||||
|
Drillia cancellata Carpenter |
|||||||||
|
DrilUa hemphilli Stearns |
|||||||||
|
Drillia incrmis Hinds |
|||||||||
|
Drillia inermis var. penicitlata Carpenter. . |
|||||||||
|
Drillia johnsoni, sp. nov |
|||||||||
|
Drillia merriami, sp. uov |
|||||||||
|
Drillia montereyensis Stearns Drillia pudica Hinds |
|||||||||
|
Drillia torosa Cakpentek |
M |
||||||||
|
Erato colnmbella Menke |
|||||||||
|
Eulima falcata Carpenter |
|||||||||
|
Eulima hastata Sowerby |
|||||||||
|
Eulima micans Carpenter |
|||||||||
|
Eupleura muriciforinis Broderip EupUura muriciformis var. ciirta, var. nov Fissuridea aspera Esch.scholtz |
|||||||||
|
Fissuridea incequalis Sowerby |
|||||||||
|
Fissuridea miirina (Carpenter) Dai.l FissurcUa volcano Reeve. |
|||||||||
|
Fusus barbarensis Trask .... |
M |
||||||||
|
Fusus luteopictus Dall |
|||||||||
|
Fusus robustus Trask |
|||||||||
|
Fusus rugosus Trask |
|||||||||
|
Gadinia reticulata Sowerby . . |
|||||||||
|
Galerus mammillaris Broderip |
|||||||||
|
Haliotis fulgeus Philippi |
|||||||||
|
* Haminca virescens Sowerby. |
|||||||||
|
Helix (Epiphragmophora), sp. indet. |
|||||||||
|
Hipponyx antiqnaius LiNNa:us |
|||||||||
|
Hipponyx cranioides Carpenter.... |
|||||||||
|
Hipponyx lumens Carpenter |
|||||||||
|
(6) |
c t |
'iV.ci. o>; |
ono |
42
GALIFOKNIA ACADEMY OF SCIENCES.
Isapis feneslrnla Carpenter
Ischnochlton rrgularis Cakpenter
Ivara terricula (Carpenter) Dali. & Bartsch.
Lacuna compacla Carpenter
Lacuna porrecla Carpenter
Lacuna solidula (Loven) Carpenter
Lamellaria steanisii Dall
Lcptolhyra bacula Carpenter
Leptolhyra carpenter! Pilsbry
Lcplothyra paucicostata Dall
a
X X
s
N N X X X X X
Liltorina planaxh (Nuttall) Philippi j X
Littorina scutulata Gould X
Lucapina crenulala Sowerby X
Macron kelletlii A. Adams S
Macron lividus A. Adams X
Mangilia angulata Carpenter N
Mangilia hoover!, sp. nov E
Mangilia interfossa var. pedroana, var. nov E
Mangilia interlirata Stearns ' X
Mangilia oldroydi, sp. nov E
Mangilia painei, sp. uov E
Mangilia sculpturata Dall X
Mangilia striosa C. B. Adams X
Margarita obtabilis var. knechti, var. uov E
Margarita oplahilis var. nodosus, var. nov E
Margarita parcipicta var. pedroana, var. uov E
Margarita pupilla Goold N
Marginella jewettii Carpenter X
Melampus olivaceus Carpenter X
Mitra maurn Swainson X
Milramorphafilosa Carpenter X
Milramorpha intermedia, sp. nov E
Monoceros engonalum Conrad X
Monoceros lapilloides Conrad X
Mopalia ciliata Sowerby X
Pleistocene.
Upper San Pedro.
K
K R
M
|
3^ |
J a; O |
|
M |
|
|
K |
|
|
M |
B |
|
C |
E |
|
E |
|
|
E |
|
|
E |
|
|
E |
|
|
M |
E |
|
E |
|
|
E |
|
|
E |
|
|
E |
|
|
E |
|
|
R |
|
|
E |
E |
|
E |
|
|
M |
E |
|
E |
|
|
C |
E |
|
E |
|
|
C |
E |
|
E |
|
|
E |
n o u u
E
R
E E
M
M
Lower Sail Pedro.
R E M R R E E R R M
E E R E
C
R E
E E
M M E
B. 3
M
E C
M
C E C
M M M
E
•O CO
E
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
43
|
a > 5 |
Pleistocene. |
Pliocene. |
|||||||
|
Upper San Pedro. |
Lower San Pedro. |
||||||||
|
■a a |
St V o |
BJ O |
a |
o |
h •O B 1^ |
to So c'o pa. |
|||
|
Murex (Pleronotus) festivus Hinds |
X N X s s X X E X c X X X X s N X X X X X X E X N s E C V X X X N X X |
R R R R M M C M E M M R R R R M R C |
c R C C M C R M R C C c M R C C R M R C R C M R C |
M R R C M R C C R M C R R M M |
R R M R R C M C M E R M R R E E R M R C |
R R R C C c E R R R E E R E M E R E c |
E M C C E E E E E E M R R 0 |
R R M M R M R R R |
|
|
Murex (Pterohytis) foliatus MaRTYN |
|||||||||
|
Murex (Pterohytis) nnttalU Conkad |
|||||||||
|
Murex (Cerostoina) monoceros Sowerby |
|||||||||
|
Murex trialatus Sowerby |
|||||||||
|
Nassa californiana Conrad |
|||||||||
|
Nassa innculpta Carpenter |
|||||||||
|
M |
|||||||||
|
Nassd Tneiidicci var. cooperi Forbes |
M |
||||||||
|
^assa perj>inguis Hin'ds |
R |
||||||||
|
N^assa tegulci Reeve |
|||||||||
|
Nalka clausa Broderip & Sowerby |
R |
||||||||
|
Natica (Lunatia) lewisli Gould |
|||||||||
|
Neverita recluziana Petit |
|||||||||
|
N^orrisia norrisii Sowerby |
|||||||||
|
Ochiebra barbarensis Gabb, |
|||||||||
|
Ocinebra foveolata Hinds |
|||||||||
|
Ocinebra interfossa Carpenter |
|||||||||
|
Ocinebra keepi, sp. nov |
|||||||||
|
Ocinebra lurida Middendorf |
|||||||||
|
Ocinebra lurida var. a^pera Baihd |
|||||||||
|
Ocinebra lurida var. cancellina Philippi |
|||||||||
|
Ocinebra lurida var. ■munda Carpenter |
|||||||||
|
Ocinebra micheli Ford |
|||||||||
|
Ocinebra perita Hinds |
|||||||||
|
Ocinebra pouhoni Nuttall Odostomia (/ouUlii Carpenter |
|||||||||
|
Odonlomia nuciformis ya,T. avellana Carpenter Odostomia tenuis Carpenter |
|||||||||
|
Olivella biplicata Sowerby |
R |
||||||||
44
CALIFOKNIA ACADEMY OF SCIENCES.
Olivella intoria Carpknteb
Olivella petlroana Conrad
Opalia hori'alis Gould
Opalia creniloide.s var. insculpta Carpentbr. .
Pachypoma incequale Martyn
Paludestrina curia, sp. nov
Paltidnslrina stokesi, sp. nov
Phaxianella r.ompia Gould
Phorcus pulligo Martvn
Phyna helerostropha Say
PIsania fortis Carpenter
Planorbis tuinidus Pfeiffer
PlanorhU verinicularis Gould
Pleurotoma (Borsonia) bartschi, sp. nov
P kuroioma (Dolichotoma) carpenteriana Gabb Pleurotoma (Dolichotoma) cooperi, sp. nov....
Pleurotoma (Borsonia) dalli, sp. nov
Pleurotoma (Borsonia) hooveri, sp. nov
Pleurotoma (Leucosy rinx) pedroana, sp. nov. . .
Pleurotoma perversa Gabb
Pleurotoma (Drillia) rniaudi, sp. nov
Pleurotoma (Spirolropsis) smithi, sp. nov
Pleurotoma (Dolichotoma) tryoniana Gabb...,
Pomaulax undosus Wood
Priene orerjonensis KedfielD
Puncturella cucullata Gould
Puncturella galeata Gould
Purpura crispata Chemnitz
Purpura saxicola Valenciennes
Pyramidilia conica var. variegata Carpenter..
Ranella californica Hinds
Rissoa aculelirata Carpenter
Scala bellnstriata Carpenter
Scala crebricostata Carpenter
Scala hemphilli Dall
CM
X X X X X E E X X X E S N E X E E E E X E E X X X N N N X
s
X
s
X X
E
Pleistocene.
Upper San Pedro.
c
R
M
M
R
E
3^
c
E
R
E E E
C
E
M M
M R
K E E E
E E E C E E M E
R C
rt o
M E
E
E
M
Lower San Pedro.
c
M
E
M
E E E E E M
E R E
•a .to
Ok 3
in
C
M
E E E E
R
E E
E
E
Pliocene.
M M
M
R
M E M
C M M
go
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDKO.
45
Scala hindsii Carpenter
Scala indianorum Carpenter
Scala iincta Carpenter
Sella assimilala C. B. Adams
Serpulorbis squamigerus Carpenter
Sigaretus debilis GocLD
Siphonalla kellettii Forbes
Solariella cidaris A. Adams
Solariella peramabilis Carpenter
Spiroglyphtis lituella MoRCH
Styliferina ienuisculpia Carpenter
Taranlf strong! sp. nov
Terebra (AcusJ simplex Carpenter
Thalotia caffea Gabb
Tornaiina cerealis Gould
Toriiatlna culcitella Gould
Tornaiina eximia Baird
Tornaiina harpa Dall
Triforis adversa MoNTAonE
Trivia californica Grav
Trivia solandri Gray
Tritonium gibbosus Broderip
Trophon (Boreotrophon) cerriiensis, sp. nov
Trophon (Boreotrophon) gracilis Perry
Trophon (Boreotrophon) muliicostatus Eschscholtz.
Trophon (Boreotrophon) pedroanus, sp. uov
Trophon (Boreotrophon) scalarl/ormis Gould
Trophon stuarti Smith
Trophon orpheus var. prcecursor, var. uov
Trophon (Boreotrophon) ienuisculpia Carpenter. .. Trophon (Boreotrophon) iriangulatus Carpenter..
Turbonilla adleri (Dall & Bartsch), sp. nov
Turbonilla arnoldi (Dall & Bartsch), sp. nov
Turbonilla aurantia Carpenter
Turbonilla crebrijllata Carpenter
X X X X X X X X
c
X
1
E X X X X X X N X X
s
E X
N E N N E E X E E X X
Pleistocene.
Pliocene.
Upper San Pedro.
K K E
M
E
C C E
M E E
M E
E
E E K
E E B
E
M
E E
•5 «
Ui
ca o u V
M M E
R
M
E
E E
Lower San Pedro.
E E E E E
E E
M E E
M
E E
E E E C C E M
E R E E E
a. 3
M E E
R
M
M M
R R
•O CO
E
R E
K R
M
E
R
R C C E
E
46
CALIFORNIA ACADEMY OF SCIENCES.
|
d > 5 |
Pleistocene. |
1 Pliocene. |
|||||||
|
Upper San Pedro. |
IvOwer San Pedro. |
||||||||
|
at |
c . a |
(J . 3>. |
St |
■S" a o |
c a Q |
e . Die |
c 2-d ! TJ W |
||
|
Tufhonilhi ijibbosci Carpenter |
X X E E S X X s s X X N N X E J X X X ? J J 9 X X X J N E |
E M R K R |
R E C C R R R C R R M R R R C |
R R R C C R R R R M C M |
M R R M |
R R R R R R R R R E R R C M E E E E C C C |
E E R R R E R R R R C R M |
c c R C R E |
|
|
Turbonilla laminaia Carpenter |
|||||||||
|
Turhonllla lal'ifundla (Dall & Bartsch), sp. nov. . . Turbonilla lowei (Dall & Bartsch), sp. nov |
|||||||||
|
Turbonilla pentalopha (Dall & Bartsch), sp. nov. . Turbonilla similimis C . B. Auams |
|||||||||
|
7'urbonilla stearnsii (Dall & Bartsch), sp. nov .... |
|||||||||
|
Turbonilla lenuicula Gould |
|||||||||
|
Turbonilla iorquata Gould |
|||||||||
|
Turbonilla torquata var. slylina Carpenter Turbonilla tridenia Carpenter |
|||||||||
|
Turrildla cooperi Carpenter |
c |
||||||||
|
Turrilella jewelii Carpenter |
|||||||||
|
Vitrin('.lla williattisoni Dall |
|||||||||
|
Volvarina varia Sowerby |
|||||||||
|
Volvula cylindrica Carpenter |
|||||||||
|
ANTHOZOA. Caryophyllia arnoldi Vaughan |
|||||||||
|
Caryophyllia californica (Vaughan), sp. nov Caryophyllia pedroensis (Vaughan), sp. nov Paracyathun pedroensis (Vaughan), sp. uov ECHINOIDEA. Echinarachnitts exceiUricua Eschscholtz |
|||||||||
|
Stronqylocunlrotus franciscanus Agassiz |
|||||||||
|
Stro7iyylocentrotus purpuratus Stimpson |
|||||||||
|
BRYOZOA. Bryozoan remains |
|||||||||
|
BKACHIOPODA. |
|||||||||
|
Terebratalia amilhi, sp. nov |
|||||||||
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
47
SCAPHOPODA.
Cadulus nitenlior Carpenter
Dentalium indianorum Carpenter
Denialium hexagonum Sowerby
Dentalium pseudohexaijonum Dall
Dentalium semipolitum Brodeeip & Sowerby
CRUSTACEA.
Balanus concavus Bronn
Cancer breweri Gabb
PISCES. Urolophus halleri ( ?) Cooper
> iJ
X
N X
X E
R
Pleistocene.
Upper San Pedro.
C M R R
M
M
" ?. 00
R C
Lower San Pedro.
•O 00
R
M C R
K
ft- 3
R
M
M
Pliocene.
a o
Chapter II,
THE UPPER PLIOCENE AND PLEISTOCENE FORMATION OF OTHER LOCALITIES OF THE PACIFIC COAST.
In discussing the occurrence of the Pleistocene deposits at other points along the Pacific Coast it will be necessary, in most instances, to quote the observations of others, as the writer has visited only a few of these localities.
The writer examined a raised beach at Blakeley Point, opposite Seattle, Wash- ington, during the summer of 1900. It consists of sandy deposits lying horizontal upon the upturned and eroded edges of the Astoria Miocene strata. This beach and one or two others in the same vicinity are about ten or twelve feet above the level of Puget Sound, showing a total thickness of about ten feet; they are of late Pleistocene age, undoubtedly later than the last ice age of that country. The following species of marine mollusks in a rather poor state of preservation were obtained from the Point Blakeley raised beach:
Macoma inquinata Purpura crispata Saxidomus aratus Tapes slaminea
Several deposits of a similar nature have been reported by J. P. Kimball' in the same vicinity. Dr. Kimball is of the opinion that there has been a recent eleva- tion of the shores of the Sound of at least twenty-five feet. This uplift has taken place since the glacial drift was deposited in that region. Dall- reports a Pleistocene deposit, overlying beds of Pliocene age, from thirty to forty feet above the sea, near Bruceport, Washington.
Mr. H. W. Turner of the United States Geological Survey collected several specimens of sandstone containing the borings and shells o( Fholadidea penita Conrad, from an elevation of fifty feet above tide water, at Fort Ross, Sonoma County, Califor- nia. Pholadidea penita not occurring previously to the Pleistocene, this evidence shows that there has been a post-Pleistocene uplift of at least fifty feet at Fort Ross.
On the flanks of several of the little valleys draining into the Bay of San Fran- cisco are deposits known to be of post-Pliocene age. Whitney describes some of these de230sits, and makes correlations which are important, if correct. He says: ^
" A post-Tertiary deposit made up of beds of gravel, sand, clay, and oyster
' Physiographic Geology of the Puget Sound Basin. By J. P Kimball. Am. Geol., Vol. XIX, 1897, p. 231. - Correlation Papers. Neocene. By W. H. Dall and G. D. Harris. Bull. U. 8. Oeol. Sur. No. 84, p. 228, 1892. a Geological Survey of California. By J. D. Whitney, State Geologist. Geology, Vol. I, p. 102, 1866.
( 48 )
AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 49
shells rests horizontally upon the upturned edges of the Cretaceous at several local- ities around Benicia. These are similar to the beds noticed as occurring on the shore between Martinez and Bull's Head Point, which contain fragments of bones of large animals and rolled Tertiary shells. Similar beds, with oysters, were observed on San Pablo Bay between Point Pinole and the Embarcadero; at this locality the beds containing oysters, which rest horizontally on upturned strata of the Tertiary, are elevated twenty feet above the level of the waters of the bay. At Benicia, also, there has been an elevation of several feet since the oyster beds were deposited. With the shells of oysters, those of other species, all now living in the waters of the bay, are found. These deposits evidently belong to the post-Pliocene, and they are of the same age as the beds of gravel, with boulders of gray .sandstone, containing the bones of the mastodon and horse, which occur at Bottle Hill near Benicia."
The Pleistocene deposits on the shore of San Pablo Bay between the Union Oil Refinery and Point Pinole have been visited by Dr. Merriam and the writer. The deposits, which rest on the upturned edges of the San Pablo strata, consist of horizontally bedded layers of sand, gravel, and clay. Teeth of the mammoth, and bones of the giant sloth and extinct bison have been found in these Pleistocene layers by Dr. Merriam. In certain places the Pleistocene layers consist almost entirely of oyster and mussel shells.
List of Fossils from the Pleistocene Deposits on San Pablo Bay between the
Union Oil Refinery and Point Pinole.
Ostrea lurida Oslrea conchaphila Mylilus edulis Tagelus cali/ornianus
The character of these Pleistocene strata and of their fauna leads the writer to coiTelate them with the upper San Pedro series.
Deposits of soft yellow sand resting on the Mei'ced (Pliocene) strata in the vicinity of Lake Merced on the San Francisco peninsula have been assigned to the Pleistocene by Lawson' and Ashley.^ The line of demarkation between the Plio- cene and Pleistocene at some places mentioned by these authors seems to be in doubt. Both are agreed that there is an unconformity between the two series, and Ashley thinks that there was a period of subaerial erosion between them.
The Pleistocene deposits mentioned by Ashley^ as occurring along the tops of the sea-cliflfs from Montara Point south are partly of fresh-water and partly of marine origin. Those at Purissima are certainly of marine origin, for pholas borings have been found in the old beach-line on which they were deposited. The deposits along the upper edge of this same terrace in the vicinity of Halfraoon Bay are of fresh-water origin, and are very recent. The Haliotis mentioned by Ashley as occurring in these deposits are from Indian kitchen-middens, common at many places along the Califor- nia coast. Similar kitchen-middens near San Mateo have been reported as Quai'ter- uary b}' the same writer.
' The Geology of the San FranciBco Peninsula. By A. C. Lawson. 15th Ann. Eep. U. S. Geol. Surv., 1895, p. 463. et seq. » The Neocene Stratigraphy of the Santa Cruz Mountains of California. By G. H. Ashley. Proc. Cal. Acad. Sci,, 2nd ser., Vol. V, 1895, p. 347, et scq.
' Op. cit., p. 349. C ' ) September 26, 1902.
50 CALIFORNIA ACADEMY OF SCIENCES.
In the region surrounding Carmelo Bay^ are numerous terraces strewn with boulders and pebbles, more or less cemented together, and in several cases with the adjoining rock surfaces showing borings which resemble those of Pholadidea penita. No fossils have been found in these deposits, but Lawson believes them to be of Pleistocene origin. He also believes that there was an interruption in the Pleistocene sedimentation, during which time orogenic movements took place. His conclusions are based on the finding of an unconformity between two of the terrace formations in a section north of Abalone Point.
Fairbanks^ tells of a large area of Pleistocene sediments lying west of Corrali- tos Creek and north of the summit of the ridge. The beds are horizontal and consist of indistinctly stratified and slightly consolidated sand. This sand formation reaches a maximum thickness of about three hundred feet. Fragments of shells are found over the surface of the deposits up to an elevation of nine hundred feet. The only shells positively identified from the surface of the beds are:
Chlorostoma hrunneum Haliotis (!) Lunalia lnwisii Myiilus californicus Purpura canaliculata
This fauna is similar to that of the Indian kitchen-middens found at so many places along the coast, and it seems probable that the shells are from deposits of this kind. Their occurrence on the surface would add weight to this theory. Another Pleistocene area in this Point Sal district is at the head of the valley north of the dairy, and consists of fragments of bituminous shale, and a deposit of calcium carbon- ate containing casts of Crepidula rugosa and a species of Purpura. Fairbanks says these beds are similar to those of Point Loma, near San Diego, " even to the presence on the surface of small concretionary nodules of sand cemented by iron oxide." ^
From Mallagh Landing, two miles southeast of Port Harford, to Pismo, and from Surf to Santa Barbara the sea-clififs are capped by deposits of sand and gravel which are probably of Pleistocene age. No fossils were found in any of the localities visited; but in several places, noticeably northwest of Pismo, pholas-bored pebbles were found at the contact between the Pleistocene sands and the underlying eroded Miocene shale, thus showing the marine origin of the Pleistocene deposits.
Santa Barbara and Vicinity.
The Packard's Hill deposits are the most important of the fossiliferous beds in the immediate vicinity of Santa Barbara. Packard's Hill is a ridge about three hundred feet in height, which begins a short distance northwest of the western end of the beach boulevard, and extends for nearly a mile due north. Its eastern slope is almost precipitous, and outcrops of the fossil-bearing strata are found over the whole slope. The best outcrops, and the one from which all the fossils were obtained by the writer, are about two-thirds of the way up the hill. The hill consists of layers of fine, soft, light yellow sand and marl, which is hardened in places
' The Geology of Carmelo Bay. By A. 0. Lawson. Bull. Dept. Geol., Univ. Cal., Vol. I., p. 62, el seq.
2 The Geology of Point Sal By H. W. Faiibanks. Bull. Dept. Geol., UniT. Cal., Vol. II., 1806, p. 6-8.
3 Of. cit., p. 8.
ARNOLD — THE PALEONTOLOGY AND STBATIGEAPHY OF SAN PEDKO. 51
by the lime leached from shells. The clip of the beds is nearly due south at an angle of 15°. The hardened strata are darker colored than the softer beds, and as a rule are more fossiliferous. The fossils in the soft strata are very fragile, but by using care some fine specimens may be obtained fi'om them.
The fauna of the Packard's Hill deposits is similar to that of the upper horizon of the San Diego formation, and is probably equivalent to that part of the Pliocene which is missing between the Deadman Island Pliocene and the overlying lower San Pedro series (Pleistocene). The close relation between the Pecten hellus Conrad found in the Packard's Hill Pliocene and the Pecten hempliilli Dall of the upper horizon in the San Diego formation is an indication of a more or less close relation between the two formations. Pecten hellus, Terehratalia hemphilli, Laqueus jeffreysi, and Vemts perlaminosn are the most characteristic specimens found at Pack- ard's Hill.
A bluff nearly thirty feet in height begins just west of the western end of the beach boulevard at Santa Barbara, and extends southwest along the ocean. For the first eighth of a mile, or along the edge of the first cove, the bluff consists of rather evenly bedded, soft, brownish yellow, sandy marl, which dips S. 30'^ E. 14°. Ai'ound the point one-eighth mile southwest of the bath-house the bluff consists of irregularl}' bedded gravels and sand, which seem at some places to rest unconformably upon the fossiliferous marl beds, although false bedding is so prevalent in the deposits along this bluff that any positive evidence as to the conformability of the strata was hard to obtain. Further southwest along the coast, the gravels and sand rest upon the upturned and eroded edges of the contorted Miocene shales. At one place about half a mile south of the bath-house, where these Pleistocene sands and gravels rest upon the Miocene shales, the Pleistocene deposits were impregnated with asphaltum. In this same place a fragment of the fossiliferous sandstone, similar to that which is found at the northern end of the bluff near the bath-house, was found in the Pleistocene gravels; thus giving evidence that there are two distinct horizons in the Pleistocene along this bluff.
Alternating strata of sand and gravel, showing false bedding, are exposed in the sea-cliff east of the Santa Barbara wharf. A sti-atum of shell fragments was found near the western end of this cliff, but no specific determination of the fossils could be made on account of their poor state of preservation. The strata of this bluff are similar to, and probably contemporaneous with, the late Pleistocene strata in the bluff southwest of the bath-house.
52
CALIFORNIA ACADEMY OP SCIENCES.
List of Fossils Collected from the Pliocene and Pleistocene Formations of
Santa Barbara, California.
|
II no. |
■a .a J |
ss o y J= o |
u |
||
|
X X X X X X X X X X X X X X X X X X X X X X X X X X X |
X X X X X X |
X X X X X X X X X X X X X X X X X X X X X X X X |
|||
|
Admefe (jrnclUor Carpenter Amphistid corruiffitit Reeve |
Mitramorpha iniermedia^ sp. nov |
||||
|
Modiola J'ornicata Carpenter |
|||||
|
Balanuti concavus Broxn Bfla fidicula Gould |
Nasna mevdica Gould Natica clatisa Broderip & Sowerby |
X |
|||
|
Bittiu m aAperum Gabb Bitiium qundr iff latum Carpenter Bryozoa sp. (?) |
|||||
|
Ocinebra lurida var. aspera Baird Ocinebra perita Hinds |
|||||
|
Odostomia nuciformis var. avellana Car- penter |
|||||
|
Calliostoma gemmuJatum Carpenter |
|||||
|
Odostomia gouldii Carpenter |
|||||
|
Ollvella hipUcata Sowerby |
|||||
|
Columbdla (Astyris) ganmjmia Gould. . . Columhe.Ua (Astyrix) (jausapata var. cnri- iicitft Hinds |
Panopea generosa Gould |
X |
|||
|
Pecten bellus Conrad |
X |
||||
|
Pecten caurimis Gould |
X |
||||
|
Columbella (Astyris) tnh-rom Carpenter. |
Pecten hastaius Sowerby |
X |
|||
|
Pecten jordani^ sp. nov |
X |
||||
|
X |
|||||
|
Pododesinus macroschisma Deshayes Protocardia centijiiosa Carpenter. Psfipkis salmonea Carpenter |
|||||
|
Diastoma, sp . (?) |
X X |
||||
|
Puncturella cuculnta Gould |
X |
||||
|
Olottidia albida Hinds |
Strongylocentrotus purpuratita Stimson. . . Terfibratrtl'nt h'^mphiUi Dall |
X |
|||
|
Laqueus jf'ffrojsi { ?) Dall |
Tornatina culcitella Gould |
||||
|
Trophon gracilis Perry |
|||||
|
Trophon orphens var. prcecursor, var. nov. Turbonilla tridenta Carpenter Vewricardia barbarctisis Stearns Venericardia venlrirosa Gould Venus pe)'lat)iiuo.sa Conrad |
|||||
|
Lucina californica Conrad Macoma sp. ( ?) M^diigilici cuufulutci Carpenter |
X X X |
||||
|
Mangilia interfossa v&t. pedrocmajXar. no v. |
Recognizable fcssils are found only in the few beds of soft, brownish-yellow marl at the northeastern end of the bluff west of the bath-house. The lowest strata exposed near the bath-house consist almost wholly of bryozoan remains, among which are scattered a few shells. The bryozoan remains give place to sand in the beds a
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 53
few feet above. The large shells in the strata are poorly preserved, but the smaller fossils, especially the gastropods, are abundant and well preserved.
The fauna of the beds west of the bath-house is similar to that of the lower San Pedro series (lower Pleistocene) of Deadman Island, and these Santa Barbara beds are probably contemporaneous with the lower San Pedro deposit of Deadman Island. Several nearly perfect tests of Strongylocentrotus pu7yuratus were found in the bath-house strata, the first tests of this species that have been recorded from the Pleistocene. Echinarachnius excentricus. was also found in the same bed. The strati- graphic relation between the Packard's Hill and bath-house beach fossiliferous deposits was not obtained, but the former are probably the older strata, although both may belong to the same series and be nearly contemporaneous.
Lithologically the two beds are somewhat similar, but faunally they differ con- siderably. The absence of Pecten hellus, Terehralalia hempMlli, Laqueiis jeffreysi and Pecten opuntia from the bath-house beach strata; and the absence of the two species of echinoderms and many species of gastropods from the Packard's Hill beds, are the noticeable differences between the two faunas.
Whitney mentions the following loaalities, besides those already cited, where Pleistocene deposits were found by the State Survey: At Hill's Ranch,' about six miles west of Santa Barbara, "the bituminous slate is covered unconformably, as at Santa Barbara, by a heavy deposit of post-Pliocene age, which here attains a thickness of from eighty to one hundred feet. The bituminous slates, which are highly con- torted and turned upon edge, lie nearly on a level with the ocean; and on their edges rests a body of soft, arenaceous, and loose gravelly materials, sometimes very slightly consolidated, and in which are long fissures filled with asphaltum." On the southwestern face- of Santa Barbara Island is a raised beach thirty feet above tide level, containing marine shells, which Whitney thinks is the same formation as that found at Santa Barbara. Near the Santa Maria River the hills of Miocene shale are capi^ed with horizontal post-Pliocene deposits.^
Dr. Stephen Bowers* describes the Pleistocene of Santa Rosa Island from notes taken by Dr. L. G. Yates: "On the north side of the island, about ten miles from the wharf, and near the mouth of Soledad Canyon, there is a fine exposure of strata consisting of about ninety feet of post-Pliocene deposits, containing fossil bones of vertebrates and at one place fossil Physas, at a depth of some seventy-five feet below the surface. This deposit is horizontal and overlies strata of older rocks, probably Pliocene, which dip 13° northeast, and contain Pectens and Turbinelias in abundance."
Judging by the fauna of the Pleistocene deposits on Santa Rosa Island, they are probably of fresh-water origin. An elephant's tooth and other elephant remains are reported by DalP as having been found by W. G. Blunt and Voy on Santa Rosa Island.
Ventura. — The most striking thing in relation to the geology of the vicinity of
1 Geological Survey of California. By J. D. Whitney, Slate Geologist. Geology, 1865, Vol. I, p. 132.
- Op. at., p. 183.
3 Op. cit., p. 137.
* Santa Rosa Island. By Rev. Stephen Bowers. Smithsonian Report, 1877, p. 317.
« Correlation Papers. Neocene. By W. H. Dall and G. D. Harris. Bull O. S. Geol. Snr., No. 84, 1892, p. 217.
54 CALIFORNIA ACADEMY OF SCIENCES.
Ventura is the great development and the high elevation above sea-level of the Pleistocene dejiosits in that locality. The terrace on which the city is located and the hills immediately back of the city are of Pleistocene origin. This is shown by the marine fauna collected at different localities in the vicinity.
The fir.st locality visited was along the course of the old irrigating ditch, which runs at an elevation of about two hundred and fifty feet above sea-level on the eastern side of the valley west of Ventura. The hills along which this ditch runs rise to over five hundred feet in height, and are composed of fine, soft, yellow sandstones which dip south at an angle of 50 . These sandstones were examined for about one-half mile north of Ventura along the ditch. This exposure represents a thick- ness of at least one thousand feet. Several of the strata were fossiliferous and yielded a fauna similar to that of the Pleistocene of San Pedro. The upper beds, or those nearest the ocean, contained a fauna similar to the upper San Pedro series, while that of the beds further down in tiie series contained such species as are com- monest in the lower San Pedro series. The lower beds were characterized by the great abundance of TurrlUUa coo'peri. An outcrop in a ravine near the new hospital on the north side of Ventura contained a fauna simij^r to that of the upper beds along the ditch.
There is an exposure of fossiliferous Pleistocene strata between Barlow's ranch house, three miles east of Ventura, and a prominent point, called "The Peak," north of the house. "The Peak" has an elevation of one thousand and seventy feet, ac- cording to the United States Coast and Geodetic Survey. The highest point at which fossils were obtained was about two hundred and fifty feet below the summit, but the same formation extends to the top, and probably comprises all of the sediments form- ing the elevated ridge which lies back of Ventura from the ocean, and extends parallel with the coast for several miles east of Ventura.
The fossiliferous strata exposed were about twenty-five feet thick, and con- sisted of five or six layers of shells from three to nine inches in thickness, separated by fine, soft, light yellow .sand layers. Tlie whole series was unconsolidated, except for local hardenings in the shell layers, and was oxidized but little. The dip of the strata was from 30° to 40° south, which corresponded nearly to the general slope of the main ridge, whose axis was parallel with the coast, and of which "The Peak" was the highest point.
The fauna collected consisted of about fifty species, all of which are common to the San Pedro series. The similarity between this fauna and that of the upper San Pedro series, and the incoherency and lack of oxidation of the matrix, leave little doubt as to the age of these beds. They are of Pleistocene origin, and, moreover, are synchronous with the upper San Pedro series. Their elevation of about eight hun- dred feet above the sea-level seems remarkable, but only confirms the theory of the recent great elevation of the coast of California from San Francisco southward.
ARNOLD- THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
55
List of Fossils Collected from the Pleistocene Formations in the Vicinity of
Ventura, California.
|
en 0 u 03 |
bet; ■CO |
in ti is (0 |
bo c . I. |
||
|
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X |
X X X X X X X X X X |
X X X X X X X X X X X X X X X X X X X X X X X X X X |
|||
|
ActtToii (Rictaxii) punctoccekUa Carpenter AiKjulus buttoni Dall |
Monoceros engonalum Conrad |
||||
|
X |
|||||
|
X |
|||||
|
Bela fidicula Gould |
X |
||||
|
Bittimn Uf^peruyii Gabb |
A^evcTtta rccluziana Petit |
X |
|||
|
Cadulus nitentior Carpenter |
Neverita rccluziana var. alta Dall Ocinehra lurida var. asprra Baird |
X |
|||
|
Cancellaria trUonidea Gabb |
X |
||||
|
Chione succincla Valenciennes |
|||||
|
Chlorosloma funebrale A. Adams Chorus belckeri Hinds |
Odostomia nuci/ormis var. avellana Car- penter |
X |
|||
|
Chrysodomus labulatus Baiud |
Odostomia tenuis Carpenter Olivella biplicata Sowerby |
X |
|||
|
Columbella (Astyris) gausapala Gould. .. Columbella (Astyris) gausapaia var. cari- nata Hinds |
X |
||||
|
Olivella intorta Carpenter |
X |
||||
|
Olivella pedroana Conrad Pecteti latiaurilus yar . monotimeris Conrad Pecten ventricosus Sowerby . , ... |
|||||
|
Crepidula adunca Sowerby Cryptomya cali/ornica Conrad |
X |
||||
|
CyUchna alba Brown Denlalium hexagonum Sowerby |
Pleurotoma carpenteriana Gabb Purpura saxicola Valenciennes |
X X |
|||
|
Donax hevigaia Deshayes |
Rissoa acutclirala Carpenter |
X |
|||
|
Drillia hemphilli Stearns |
|||||
|
Drillia inermis Hinds |
X |
||||
|
Drillia inermis var. pcnicillala Carpenter |
Scala tincta Carpenter |
||||
|
Echinarachnius excentricus Eschscholtz. . |
Tapes tenerrima Carpenter |
||||
|
Eulima micans Carpenter |
|||||
|
Eiilima haslaia Sowerby |
|||||
|
Lacuna compacta Carpenter |
|||||
|
Littorina scutulata Gould |
X |
||||
|
Mncoma nasuia Conrad |
Turbonilla laminata Carpenter Turbonilla, four sp. ( ? ) |
||||
|
Mactra catilliformis Conrad Mangilia angulata Carpenter |
|||||
|
Mangilia sp. (?) |
Watts and Cooper give lists of fossils from several localities in Santa Barbara, Ventura and Los Angeles counties' which suggest the Pleistocene age of the deposits
' The Gas and Petroleum Yielding Formations of the Central Valley of California. By W. L. Watts. Bull. Cal. State Mining Bureau, No. 3, 1884.
Lists of Fossils Identified by Dr. J. G. Cooper. Oil and Gas Yielding formations of Los Angeles, Ventura, and Santa Barbara counties. By W. L. Watts. Bull. Cal. State Mining Bureau, No. II, 1897, pp. 79-87.
56
CALIFORNIA ACADEMY OF SCIENCES.
from wbicli the fossils were taken. The faunas are generally so small, and the strati- graphic notes so incomplete, that it is not possible to make any definite correlations between these deposits and the different horizons of the San Pedro series.
Port Los Angeles. — The writer has obtained the following species from a hard, sandy stratum underlying more than a hundred feet of soft, sandy deposits in the mouth of the canyon at the end of the large wharf at Port Los Angeles, near Santa Monica:
Asli/ris gausapala
Beta sanche-monkcE
Bittium aspe.rum
Nassa mcndica var. cooperi
Nasaa pcrpinguis
Nevi-rila rccluziana
Olivella biplicala Olivella intorta Osirea lurida ( ?) Pisania fortis Pleuroloma carpenieriana
Plcnrotoma perversa Tapes slaminea Turritella cooperi Trophon scalari/ormis Vencricardia venlricosa
The stratum from which the above fossils were obtained is probably Pleisto- cene, corresponding to the lower San Pedro series of Deadman Island, for lithologically and faunally the strata are quite similar. The overlying beds are soft and unfossilifer- ous, and lie slightly unconformably on the lower fossiliferous stratum; and although they contain no fossils, still, from lithological and stratigraphical reasons, it is probable that they are equivalent to the upper San Pedro deposits. These Pleistocene strata ex- tend down the coast from the great wharf to about one-half mile below Santa Monica.
8an Clemente Island. — The post-Pliocene deposits of San Clemente Island are small. W. S. T. Smith' says that they consist of fine sand and rolled pebbles, and have a maximum thickness of only ten feet. Lucina californica is the only fossil shell reported from these deposits.
Neivport. — Much of the coast line from Long Beach to San Diego consists of more or less elevated deposits of Pleistocene age. Deposits of Pleistocene age have been examined by W. L. Watts in the vicinity of Newport, Orange county.^ About a mile north of the town of Newport is a formation of soft sandstone and yellowish clay-shale, with layers of hard calcareous strata, and some strata which appear to be made up largely of diatomaceous material. These deposits contain the following species, which have been identified by Dr. J. C. Merriam:
Anomia lampe Crucibulnin spinosum Placunanomia macrosehisma
Cardiumpanamense[^=C. procerum} Macoma inquinata Potnaidax undosus
C'hione similUma Ncverita reciuziana Tapes slaminea
Chione succincta Pecten ccquisulcaliis [)^P. ventricosusi Zirphcea crispata [r=Z. Gabbi]
The fauna given above shows that this deposit is equivalent to the upper San Pedro series.
The oil-sand and sandstone west of the inner bay at Newport contain the following species:^
BiUiuin aspcrum Bryozoau remains Crepidula aduncn Lucina californica
Macoma inquinata Monoccros enyonutum Nassa fossata Nassa perpinrjuis
Olivella biplicala Prlricola cardiloides Tapes slaminea
This fauna corresponds to that of the upper San Pedro series, although no definite relation can be established, owing to the lack of characteristic fossils.
1 A Geological Sketch of San Clemente Island. By W. S. T. Smith. 18th Ann. Kept. D. S. Geol. Sur., Part II., 1S98, p. 492.
= Oil and Gas Yielding Formations of California. By W. L. Watts. Bull. Cal. State Mining Bureau, No. 19, 1900, pp. 61 and 223.
3 Op. cit, p. 233.
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO 57
San Juan Capistrano. — The following fossils were taken from a shallow well at San Juan Capistrano, in which were also found a tusk and some of the hones of a mastodon:*
Area (cf.) sulicosta Natica ciaiisa Turril.'Ua roopi'ri
Crepidula I'xcavata OstrKi (?) Venericardiabomnlis \^=V. vcntricosal
Nassa mendica Leda ( ?) Vola ( ?)
Dr. Merriam is of the opinion that these fossils are of Pliocene age — an opin- ion borne out by the similarity of this fauna to that of the Deadraan Island Pliocene.
At Bell Station, on the Los Angeles Terminal Railway in Los Angeles County, the following fossils were obtained from a well at a depth of between 920 and ],320 feet."
Amiaiitis callosa Mi/uiwl/a (aff.) .^hn/tlcx [^7'crc- (Hivella hfjulira [=0. pcdroafia]
Echiiiarachnius exr.i'nlrirus bra id.] Ktela unduinta
Macoma nasuta Lunatia leirhti Tornaiella ( ?)
This is an upper San Pedro fauna, anil its occurrence at such a great depth
has much significance in showing the great amount of sedimentation that has taken
place in the region between Los Angeles and the ocean since the deposition of the
San Pedro series.
San Diego and Vicinity.^
The Pliocene and Pleistocene deposits of San Diego are similar to those of San Pedro, and the geologic hi.story of the two regions has been nearly the same. During the Pliocene epoch the region now occupied by San Diego Bay and vicinity was a great basin in which coarse gravels and fine sands were depo.sited. The earlier sediments, which are now exposed along the northern portion of the San Diego mesa, consist of thick deposits of incoherent coarse gravels, while the later deposits are made up of plainly bedded yellow sandstones. After the deposition of these layers, there was an interruption of sedimentation, which was followed during Pleistocene times by an inundation and deposition of fossiliferous gravels and sands over much of the San Diego region.
Pacific Beach — Pliocene. — The best exposure of the Pliocene is found at Pacific Beach, on the coast ten miles north of San Diego. A perpendicular blufi, varying in height from four feet at Ocean Front to over sixty feet one mile north, forms the coast line of Pacific Beach. This bluff is composed of brownish yellow sandstones of Pliocene age, which dip gently toward the south, and disa^ipear succes- sively beneath the beach as one approaches Ocean Front from the north. The total thickness of the strata exposed is about two hundred feet. The upper one hundred feet are fossiliferous, while the lower layers are devoid of fossils. The unfossiliferous sandstone rests upon coarse incoherent gravels of unknown thickness.
There appear to be two quite distinct horizons in the fossiliferous section of the Pacific Beach Pliocene. Stratigraphically no distinction can be made, as the whole series of strata rest conformably upon one another, but faunally there is
1 Op. tit., pp. 59 and 222. 'Op. cit., p 223.
<< The late Tertiary and Pleistocene formations in the vicinity of S.in Diego are mentioned in the following papers:
Distribution of California Tertiary Fo.ssils. By W. H. Ball. Proc. U. S. Nat. Museum, Vol I, 1879, pp. 26-30. North American Tertiary Horizons. By W. H. Dall. 18th .\na. Rept. U. S. Cleol. Sur., Part II, 1898. p. 335.
Geology of San Diego County; also of portions of Orange and San Bernardino Counties. By H. W. Fairbanks, lltb .\nn. Kept. Cal, State Mineralogist, 1893, pp. 76-120. ( 8 ) September 27, 1902.
58 CALIFOK'NIA ACADEMY OF SCIENCES.
much difference between the two horizons. The lower fossiliferous strata are distin- guished by Pecten expansus, Pecten steanisii, Opalia anomala, and Opalia varicostata, Pecten expansus being very numerous. The upper beds have few Pecten expansus, but are characterized by Pecten hemphilli, which complete!}' replaces the Pecten stenrnsii of the lower layers. Echinarachnius excentricus and Crepiduln grnndis are also conmion in the upper layers.
The series of Pliocene strata exposed at Pacific Beach has been named the San Diego formation by Dall,' who places it below the Merced formation. At another place in this paper the writer brings forward reasons for placing the San Diego form- ation above the Merced. Besides the reasons given at that place (page 17) there is other evidence showing that the San Diego formation is part of the latest Pliocene. This is the occurrence in it of Echinarachnius excentricus. This species of echinoderra is not found in the Merced series or in any of the underlying formations, so far as known, but is found in the lower San Pedro series (lowest Pleistocene) and in all of the succeeding formations, and is still living. Considering the short geologic range usually covered by species of echinoderms, this evidence strongly favors the theory that the San Diego formation is at the top of the Pliocene, and probably takes in a part of the lower San Pedro series.
The lithologic and stratigraphic similarity of the San Diego formation to the Deadman Island Pliocene is marked. Both consist of rather fine, brownish yellow sand strata only moderately consolidated, except locally, with low dip, and showing the effect of only a slight movement since their deposition. Both formations are overlain unconformably by strata of Pleistocene origin. The fannal aspects of the two formations are somewhat different. Pecten ex'paasus of the San Diego formation replaces Pecten caurinus, which is abundant in the Pliocene of Deadman Island, and numerous species are found in the Deadman Island Pliocene which do not occur in the Pacific Beach Pliocene deposits. Pecten stearnsii is common to both formations, and as its geologic range is very limited, it is strong evidence of the contemporaneity of the two formations. Correlating more accurately, the Deadman Island Pliocene is probably contemporaneous with the lower (Pliocene) horizon at Pacific Beach, for Pecten stearnsii is limited to that horizon in the San Diego formation, so far as is known.
Pacific Beach — Pleistocene. — The upper six to ten feet of the Pacific Beach bluff is composed of a gravel and sand formation which rests unconformably upon the Pliocene strata. The line of demarkation between the Pliocene and the upj)er Pleistocene formation is generally distinct, as the lower layer of the Pleistocene is of coarse, fossiliferous gravel, while the underlying Pliocene strata are of fine sand. Well preserved fossils are found at many points in this Pleistocene layer along Pacific Beach, while at other places in the same stratum the fossils are so brittle that it is im- possible to remove them from the soft matrix. The fauna of this Pleistocene stratum is very similar to that of the upper San Pedro deposits exposed at the north point of the San Pedro bluff. The break between the faunas of the Pacific Beach Pliocene and the overlying Pleistocene is much greater than that between the Deadman Island Pliocene and its overlying Pl'eistocene (lower San Pedro series) layer.
1 North American Tertiary Horizons. By W. H. Dall. 18th Ann. Bept. U. S. Oeol. Sarvey, Part II, 1898, p. 386.
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 59
San Diego Mesa — Pliocene. — The San Diego mesa is composed of Pliocene strata. Outcrops of the soft yellow and brown Pliocene sandstone occur in many places in the northern part of the city. A good exposure is found at the north end of Tenth street, a short distance northwest of the Russ school, where a cut on both sides of a small ravine reveals a section of the Pliocene about fifty feet thick. This exposure is only about two hundred feet noi'th of the "San Diego well," which was dug about twenty years ago, and which has become famous through the discussion of the age of the fossils which were taken from it. Mr. Hemphill, who obtained the fossils from this well during its excavation, informed the writer that fossiliferous strata were penetrated to a depth of one hundred and forty-nine feet. As the exposure of the San Diego formation above the mouth of the well is fifty feet thick, the fossil- bearing strata of the Pliocene formation of the San Diego mesa are at least two hun- dred feet in thickness. The dip of the strata above the well is south, or toward the bay, at an angle of eight or ten degrees.
Twenty-sixth Street — Pleistocene. — A bluff about eighteen feet high rises from the edge of the bay at the foot of Twenty-sixth street, San Diego, and extends for two or three blocks both toward the east and toward the west from Twenty-sixth street, forming the shore line along this part of the bay. At the base of this bluff, and covered by the water at liigh tide is a stratum six inches thick made up almost entirely of the upper valves of Anomia limatula. No right valves were found in this deposit, and this species seemed to be restricted to this layer. A stratum of fine, yellow fossiliferous sand, four or five feet thick, rests upon the Anomia beds; and above the fossiliferous bed is about twelve feet of fine brown sand, overlain by sandy soil. Dosinia poiiderosa, Oallista newcombiana, Mactra californica, and Cardium pro- ceruin are the predominating species in the yellow sand stratum. The fauna of this locality is equivalent to that of the upper San Pedro series at San Pedro.
Spanish Bight — Pleistocene. — The Coronado peninsula is a long, low, narrow sand-spit lying between San Diego Bay and the ocean. Near its western end is a small inlet on the bay side, known as Spanish Eight. The western shore-line of this inlet is a bluff' varying in height from twelve to eighteen feet, while the stratum at the base of the bluff forms the beach, and is covered by the water at high tide. This lowest layer is composed of a firm, fine brown sand in which are imbedded numerous large Amiantis callosa, which have the appearance of living shells, so naturally do they lie on the sand. An attempt to remove them, however, dispels the delusion, for in most cases they are quite firmly imbedded in the sand layer.
There are three feet of fine, soft, unfossiliferous gray sand above tlie Ainiantis layer, and this is overlain by a deposit, varying in thickness from three to five feet, of soft gray sand, which is very fossiliferous near its base and gradually grades into the almost unfossiliferous gray sand a few feet above. About twelve feet from the base of the bluff is a layer from three to six inches thick containing numerous Donax Icevigata cemented together. This Donax layer is the uppermost fossiliferous stratum the bluff above this being composed of unfossiliferous sands. The fauna of the Spanish Bight deposits is similar to that of the upper San Pedro series at Los Cerritos, and the deposits are probably of contemporaneous origin.
60
CALIFOENIA ACADEMY OF SCIENCES.
List of Fossils Collected from the Pliocene and Pleistocene Fokmations of ^ San Diego, California.
Acmtea insessa Hinds
Acmeea pelta Eschscholtz
Actceon Iraskii Stearns
Actaion ( Riclaxis) punc/ocrelala Carpenter
A miantis callona CoNRAU
A mphiasa versicolor Dall
Anomia lamjx' Gray
Anomia liinafula Dall
Astarte branneri, sp. nov
Balanus concavus Bronn
B'Utium aupp.rum Gabb
Bitlium williamsoni , sp. nov
Cadulus nilenlior Carpenter
Cattista newcombiana Gabb
Calliosloma canaliculalum Martyn
CaUiostoma costatum Martyn
CalUostoma gi'mmulatum Carpenter
CaUiostoma tricolor Gabb
Cancer, sp. indet
Cardium procprum Sowerby
Cardium quadrigenarinm Conrad
Cerithidca cali/ornica Haldemann
Chione fluctifraga Sowerby
Chione simillima Sowerby
Chione. succincla Valenciennes
Chlorostoma fuiiehralf A. Adams
Chloroxloma ijallina Forbes
Chlorostoma tnontercyi Kiener
Clidiophora punctata Conrad
Clypide.Ua bimaculata Dall
Columbella ( Msopiis) chrysalloidea Carpenter
Columhella ( Astyria) ijausapata Gould
Coluinbella (Astyris) gausapata var. carinata Hinds.
Columbella ( Aslyris) tuberosa Carpenter
Conns cnli/oriiicus Hinds
Pleistocene.
O Vi
X X
X X X X X X
X X X
an
X X X
X X
X X X X
10 •=
(1<B
X X
X X
X X
X X
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO.
61
Cooperdla subdiaphana Carpenter
Corbula lute.ola Carpen'ter
Crepidula adunca Sowerby
Crepidula grandk Middendorf
Crepidula onyx Sowerby
Crucibulum spinosum Sowerby
Cryplomya califoraira Conrad
Cylichna alba Brown
Delphinoidea coronadoennis, sp. nov
Dentalium hexarjoiium Sowerby
Denlalium pseudohexagoniim Dall
Diplodonta orbella Gould
Diplodonta srrricata Reeve
Donax Imvir/ata Deshayes
Dosinia pondi'rosa Gray
Drillia canrellata Carpenter
Drillia hemphilli Stearns
Drillia incisa Carpenter
Drillia inermis Hinds
Drillia inermis var. penicillata Carpenter . Echinarachnius excentricus Eschscholtz.. .
Eulima hastala Sowerby
Mulitna micans Carpenter
Eupleura muriciformis Broderip
Fissurella volcano Reeve ,
Olycymeris barbarensis Conrad
Haliotis falgens Philipp i
Hipponyx cranioides Carpenter
Hipponyx lumens Carpenter
Kellia laperousii Deshayes
Lmvicardium subsirialum Conrad
Lacuna compacta Carpenter
Lacuna solidula (Loven) Carpenter
Lamellaria slearnsii Dall
Leda hamata Carpenter
Leda taphria Dall
Littorina scutulata Gould
Lucina aculilineata Conrad
Pleistocene.
O V
X X
X X X X
X X X X X
X X
X X X X X
X X
X X X
«■=
X X
X X X X
X X
X X X
(UK
62
CALIFORNIA ACADEMY OF SCIENCES.
Lucina californka Conrad
Lue.ina nuttalli Conrad
Lucina Unnisculpla Carpenter
Macoma imlentata Carpenter
Macoma inrjuinala Deshayes
Maeoma nasnta Conrad
Macoma namila var. keheyl Dall
Macoma xecla Conrad
Macoma yoldiformis Carpenter
Mactra cali/ormra Conrad
Mactra (Spixula) catilliformin Conrad
Mactra cxoleta Gray
Mactra (Spixvia) falrala Godld
Manii'iUn unijulala Carpenter
Mantjilia /tlriona C. B. Adams
Melampus olivareun Carpenter
Metis alia Conrad
Modiola recta Conrad
Monoceron enrjonatum Conrad
Murcx ( Ptrrohytis) nul.lalli Conrad
NoHSa californiana Conrad
Nasaa ccrritennis, sp. nov
Nassa/onxata Gould
Nassa mcndirn Gould
Nassa inrndica var. rooperi FoRBE.s
NanKa pcrpini/uit: Hinds
Nassa teyula Reeve
Neverita recluziana Petit
Norrinia norrinii Sower by
Nucula supraxlriata Carpenter
Ociiiebra interfoxsa Carpenter
Ocinchra /uridn Middendorf
Ocinchra pouhoni Nuttall
Ocini'bra perita Hinds
Odostomia nuciformis var. avellana Carpenter
Odoslomia tenuis Carpenter
Olivella biplicata Sowerby
OUvella intorta Carpentee
Pleistocene.
X X
X X X
X X X
X X X
(J a
CO
X X
X X
X X
X X
X X
i
X X
■^ I
X I X X
X
X
X X X X
X X
X
X
X X
u m
X X
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
63
|
Pleistocene. |
1 Pliocene. |
||||
|
S.5P |
(J rt CO 04 |
a n PhP3 |
X O |
||
|
Otivellct pedrocnift Conrad . |
X X X X |
X X X X |
X X X X X X X X X |
X X X X X X X X X X |
|
|
Ostrca liirida Carpenter |
|||||
|
Oslrea vcatchi { ? ) Ga bb |
X |
||||
|
Pecti'n cxpuiisHs Dall. |
|||||
|
Fecial haMatus Sowerby Pe.cten hemphilH Dall |
X |
||||
|
Pr.ctfn hericeux Gould |
|||||
|
Pecien laliauritus Conrad |
|||||
|
Pecten latiaurilus var. monotimrrh Conrad |
|||||
|
Pecten subvenirkoKus Dall |
|||||
|
Periploma argeniaria Conrad |
|||||
|
X X 1 X |
|||||
|
Phasianella compla Gould |
1 |
||||
|
Plcuroloma carpenteriann Gaee |
|||||
|
X |
|||||
|
Pomaulax undosus Wood |
X X X X |
||||
|
Purpura crispala Chemnitz |
X X X X X X X X |
X X X X X |
X |
||
|
Saxidomus aralus Gould |
|||||
|
Scala lincta Carpenter |
X |
||||
|
Semele pulchra Sowerby |
|||||
|
Siliqtin lucidn Conra d Silitjiia palula var. nutlnlli Conrad Siphonalia keUettii Forbes |
|||||
|
Slrongylocentrotus purpnratus |
|||||
|
Tapes sCaminea Conrad |
X |
||||
64
CALIFORNIA ACADEMY OF SCIENCES.
Tapes lenerrima Carpenter
Te.Uina hodeijensU Hinds
Terebra simplex Carpenter
Tivi'la crnssnlelloides Conrad
Tornalina cerealis Gould
Tornalina cukilelln Gould
Tornalina hnrpa Dall
Trtsus nuUalli Conrad
Turriti'Ua rooperi Carpkntkr
Turbonilla (four species)
Vilrinella, sp. iudet
Vnu'ricardia ven/ricosa { ? ) Gould
Voloarina ttnrla Sowerby
Volvula cylindrica Carpenter
Yoldia coopcri Gabe
Pleistocene.
X .X
X X X X X X X X
X X
PhP3
u cd
Chapter III
FAUNAL RELATIONS.
1 . Pliocene.
The fauna of the Deadman Island Pliocene strata is somewhat similar to the fauna which is now living in the waters only a short distance oflshore from San Pedro. Dredging' has shown this, and has also shown that the sediments now being deposited off San Pedro are similar to those which make the strata of the Deadman Island and Timm's Point Pliocene. The Pliocene strata consist for the most part of rather fine clayey brown sand which has its counterpart in the fine sand and mud now being deposited off shore from San Pedro. The Pliocene fauna, although quite similar to the fauna now living off San Pedro, still has many species which are found living only north of that place. To state it more precisely, 18.5 per cent, of the species found in the Deadman Island Pliocene fauna are found living now only to the north of San Pedro. Many of these northern species are limited in range to the boreal waters north of the Puget Sound district. The occurrence in large numbers in the Deadman Island Pliocene of Pecten caurinuii, Fanomya ampla, Thyatiira hixect<i, Pecten hericeut<, Lucimi acuiilineata, Natica clauna, several species of 2ropho7i, and other boreal and subboreal forms, leads to the conclusion that the strata in which they occur were deposited in water probably much colder than that which is found offshore from San Pedro at the present time. The species found fossil in the Deadman Island Pliocene, and still living at San Pedro, also offer evidence of the northern climatic conditions during later Pliocene times. Of the species living at San Pedro at the present time, and found fossil in the Pliocene, nearly all are more common toward the north. In fact, San Pedro is the southern limit of the known range of many of the species. Boreal or subboreal conditions so near the shore imply more or less similar climatic conditions on the land, at least near the ocean. This being the case, it is more than probable that during the latter part of the Pliocene epoch the climate was much colder on the coast of Southern California than it is at the present time.
^ During the summer of 1901 dredging was carried on in the waters adjacent to San Pedro, Catalina Island, and San Diego, by a party of zoologists under the supervision of Dr. W. E. Ritter, of the University of California. The information obtained by the party was very important, and that regarding the mollusca was especially so to the conchologists and paleontologists of this coast, as it extended the known southern range of many species heretofore known only north of San Pedro. To Professor Raymond, who had charge of the molUisca obtained, and to Mrs. Oldroyd, who assisted in the classification of the same, the writer is indebted for much of the information regarding the offshore fauna near San Pedro.
( 9 ) [65] June 10, 1903.
66 california academy of sciences.
2. Pleistocene.
The Lower San Pedro Series. — The lower San Pedro strata of Deadman Island and the San Pedro bluffs were dejiosited in water shallower than that in which most of the underlying Pliocene strata were laid down. The sediments and fauna of the lower San Pedro deposits show this. The sediments consist for the most part of medium grained gray sands such as are being deposited at the present time in about ten to twenty fathoms of water off the San Pedro shore-line. The occurrence in the lower San Pedro deposits of many species which live only between tides also oflfers evidence of their close in-shore deposition. The fauna of the lower San Pedro series is one of transition between the boreal or subboreal fauna of the later Pliocene and the semitropical fauna of the upper San Pedro series. Two causes account for this. First, the deposits being laid down in shallower water than that in which the Pliocene sediments were deposited would necessarily contain fewer of the colder, deeper water forms of the Pliocene; and second, the cold climatic conditions prevalent during the later Pliocene epoch were giving place to a warmer climate, which had its effect upon the boreal species which inhabited the water off San Pedro during Pliocene times.
The species found in the lower San Pedro deposits and now found living only north of San Pedro comprise 17.4 per cent, of the lower San Pedro fauna. This percentage is only a little lower than that of the northern species found in the Plio- cene (the latter being 18.5 per cent.), and shows, considering the fact that the lower San Pedro beds were deposited in shallower water than that in which the Pliocene was laid down, that the climatic conditions had changed but little during the period intervening between the deposition of the Pliocene and lower San Pedro series. The evidence offered by several species (3.4 per cent, of the entire lower San Pedro fauna) which are found in the lower San Pedro series, but are now found living only south of San Pedi-o, shows, however, that the conditions of temperature were changing.
Besides the distinctly northern forms which either disappear or become scarce in the period between the Pliocene and lower San Pedro series, there are many species best suited for northern conditions which become rare in the lower San Pedro series, while species best suited for southern conditions begin to increase in num- bers. All of the evidence shows that climatic conditions were changing from boreal towards tropical during the time of the deposition of the lower San Pedro series. That the boreal conditions still preponderated during this period, however, is shown by the fauna of the lower San Pedro.
The Upper San Pedro Series. — The deposits of the upper San Pedro series consist of coarse gravels, and sands which show alternating dune and water bedding; and the rapidly changing conditions under which the deposits were laid down is evi- denced by their variation. The fauna of the upper San Pedro series is southern in character, and, as would be exi^ected, approaches more nearly the present living fauna of the San Pedro region. Being deposited in shallower water tlian either the Pliocene or lower San Pedro deposits, one would expect it to contain fewer of the cold water species and more of the species found only between tides and in the warm
ARNOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDEO. 67
waters of the lagoons. Such is the case, but it is a noticeable fact that in the upper San Pedro fauna 14.2 per cent, are species which are found living at the present time only south of San Pedro. Not only is this true, but of the species in the upper San Pedro fauna which are now living at San Pedro a lai'ge number are best suited for southern conditions.
Although 6.1 per cent, of the upper San Pedro fauna ai'e found now living only north of San Pedro, these northern species are only very rarely found in the upper San Pedro deposits. On the other hand, not only are most of the southern forms common in the upper San Pedro series, but the whole fauna has a semitropical aspect. Such sp)ecies as Cardium elatum, Area lahiata, Peden dentatus, Mactra exoleta, Venus giiidia, Murex keanus, Eiqjleura muriciformis., Cancellaria tritonidea, and Bulla jmnctalata give this fauna its tropical character. The evidence offered by the southern forms outweighs the evidence of the northern species in another respect, for it would require a great change in climate from the conditions prevalent during later Pliocene times to cause these southern sjiecies to migrate northward to the San Pedro region; while this same change in climate would not so visibly affect the northern species, for they could simply migrate into deep water, where the conditions would more nearly approximate the boreal. This latter has been the case with such species as Lucina acutilineata, Chrysodomus tabulatus, Solariella cidaris and Solnriella peramabilis, which now inhabit northern waters, near shore, but which have been dredged in the deep water between Catalina Island and the mainland.
The evidence offered by the upper San Pedro fauna leads to the conclusion that semitropical conditions prevailed during the deposition of this formation. The similarity of the fauna of these beds with that now living at San Pedro and the adjacent coast makes it probable that the conditions, although more tropical than those of the present time, were not extremely tropical.
3. Relation of the Late Pliocene, Pleistocene, and Living Faunas of
California to the Fauna of Japan.
Great similarity exists between the late Tertiary and Pleistocene marine in- vertebrate fauna of Japan and that of the western coast of the United States. This similai'ity is shown by a comparison of the species found in the uppermost Tertiary deposits in the region about Tokio and the species found in beds of similar age along the Pacific coast of North America.
Dr. Brauns' has described some of the formations in the vicinity of Tokio, and has given lists and descriptions of the fossils found in these formations. Dr. Brauns thinks that the deposits he has examined are of the uppermost Tertiary. His lists of fossils lead to that conclusion, if one compares them with the fauna of the later Plio- cene of California. Many of the Japanese species have counterparts in species found in the San Pedro deposits. Such species, for example, as Lucina borealls, Cylichna cylindracea, and Fecten yessoensis are closely related, if not identical, with the west
1 Geology of the Environs of Tokio. By David Brauns. Mem. Sci. Dept. Univ. of Tokio, No. 4, 1881, pp. 27, 61.
68 CALIFORNIA ACADEMY OF SCIENCES.
American species, Lucina acutilineata, Cylichna alba, and Pecten caurinus. There are many such cases of the similarity of species, and in a few instances identical species have been found which are common to the two regions. The following species are found in Dr. Brauns' list of upper Tertiary fossils from Ojai, near Tokio, which are also found in the San Pedro deposits:
List of Fossils from Ojai, which are Found in the San Pedro Deposits.
Cardium cnli/orniense[= C. forhis] Kellia suborbiculnris Panopea gencrosa
CrepkliUa acuhata Macomn nasuta Tresvs nullalll
Among the species now found living in Japan, and on the west American coast, and also found in the San Pedro deposits, are the following:'
List of Living Species Common to Japan and the West Coast of North America, which are Found in the San Pedro Deposits.
Cardium corbis Macoma nasula Sawjuinolaria nullalU
Crepidula grandis Macoma secta Siphonalia kellellii
CryptochHon siclleri Mytilus eduUs Tresus nultalU
Dentalium hexagonum Natica clausa Tapes staminea
Drillia inermis Pectan hericens Tellina bodegennis
Leploihyra carpenleri Purpura crispata Tritonium ( =^ Prkne) oregonrnais
Macoma edulis Panopea generosa Trophon orpkeus (^ T.sluarti{'>))
Macoma inquinata Pododesmus macroschism.a
The living faunas of the Japanese and west American coasts, though having many species in common, are not as closely related as are the upper Tertiary and Pleistocene faunas of the same regions. This has been brought about in two ways. First, the more or less close connection between the two regions, which existed in late Tertiary and early Pleistocene times, has been broken; and second, southern species from the warm China seas have migrated northward and mingled with the Japanese early Pleistocene species, while Panama species have come northward during the upper San Pedro time and changed the aspect of the fauna of the west coast of North America. Those species which Japan and the west coast of North America have in common are either circumboreal or are forms which have changed little since the habitats of the two faunas were similar and connected; those species which differ but slightly have in many cases made this change since the connection was broken; and many of the forms which occur in each fauna, and which have no counterpart in the other, have come into these faunas in comparatively recent times.
An interesting example of the migration which took place between Japan and western North America is offered by the genus Halioth. This genus is of Asiatic origin, but it migrated to the northern American coast during late Pliocene or early Pleistocene times. This is shown by the absence of this species from any of the pre- Pleistocene formations along this coast. Only two fossil Haliotidm have been found on this coast, one being taken from the upper San Pedro (Pleistocene) gravel of
^ TblB liBt Is compiled from the foUowiDg papers: Mollusks of Western North America. By P. P. Carpenter. Smithsonian Miscellaneous Collections, No. 252, 1872. Catalogue of California Fossils. By J. G. Cooper. 7th Ann. Kept. Cal. State Mineralogist, 1888.
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 69
Deadrnan Island, and the other from the Pleistocene (upper San Pedro series) at Spanish Bight, San Diego. The nearly total absence of this species from even the Pleistocene deposits is accounted for by the length of time it would take the species to migrate to the California coast from Alaskan waters, where it first reached the American shore during Pliocene or early Pleistocene times. This scarcity of the Haliotidce, which are so common in the living fauna, in even the upper San Pedro deposits, is more evidence in favor of the theory that a long period of time has elapsed since the dejiosition of the upper San Pedro series.
Dr. J. P. Smith explains the phenomena of the similarity of the late Tertiary and early Pleistocene fauna, and the somewhat similar, though diverging, living faunas in this way: during Tertiary time there was an elevation of the submarine shelf which follows the line of the Aleutian Islands. This elevation made possible the intermigration of many species which oiherwise never could have crossed the abyssal gap which now separates the northwestern American and Japanese regions. After the elevation of this shelf it remained in a more or less constant position for some time, and then became deeply submerged again, with a consequent breaking of the faunal connection between the two regions.
From the evidence brought forward in this paper, it has been seen that the late Pliocene and early Pleistocene was a period of the southward extension of boreal conditions on the west American coast; it would, therefore, be natural to infer that approximately the same conditions prevalent on the Californian coast during late Pliocene times also prevailed along the Japanese coasts during the same period. A detailed study of the Tertiary and Pleistocene deposits of Japan is awaited with interest, as such a study will throw more light on the conditions prevailing on the shores of the North Pacific during the later geologic epochs.
Part II. Descriptions of Species
THE PLIOCENE AND PLEISTOCENE FAUNA OF SAN PEDRO
AND VICINITY.
Synopsis.
Page
CCELENTER ATA 86
CL.\SS I. ANTHOZOA 86
Family I . Txirhinolidoi 86
Genus Caryophj'llia 86
1. arnoldi Vaughan 86
2. pedroeusis v., sp. iiov 87
3. califoruica V., sp. uov 87
Genxis Paraoyathua Milne-Edwards & Haimf 88
4. pedroeusis V., sp. uov 88
ECHINODERMATA 90
CLASS II. ECHINOIDEA 90
SUBCLASS EUECHINOIDEA 90
Order Diadematoida 90
SOBORDER StEREOSOMATA 90 .
Family II. Echinomelridie 90
Geaus Strougyloceutrotus Brandt 90
5. francisoauus A. Agassiz 90
6. piirpuiatus Stimp-son 90
Order Cltpeastroida 91
Family III. Scutellidce 91
Genus Scutella Lamarck 91
Subgenus Ecbinarachnius Leske 91
7. (E.) excentricus Esch.scholtz 91
MOLLUSCOI DE A 92
CLASS III. BKYOZOA 92
8. Sp. iudet 92
CLASS IV. BRACHIOPODA 92
Order Arthropomata 92
Family I V . Tercbraliilida: 92
Genus Teiebratalia Beecher 92
[S. B.] hemphilli Dall 92
9. sniithi, sp. nov 93
Geuus Laqueiis Dall 93
10. Jeffreys! Dall 93
Family V. Lingulidte 94
Subfamily Lin;/ulince 94
Genus Glottidia Dall 94
[S. B.] albida Hinds 94
(71 )
72 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSCA 95
CLASS V. PELECYPODA 95
Order Prionodesmacea 95
SUPERFAMILY NUCULACEA 95
Family VI. NuculUlce 95
Genus Nucula Lamarck 95
Subgenus Acila H. & A. Adams 95
11. (A.) caslrensis Hinds 95
Subgenus Nucula, s. s 96
12. (N.) suprastriata Carpenter 96
Famibj Via. Ledidm 96
Genus Leda ScHnMACHER 96
13. fossa Baird 96
14. hamata Carpenter 97
15. minuta Fabr., var. prascursor, var. nov 97
16. taphriaDALL 98
Genus Yoldia MIjller 99
17. cooperi Gabb 99
IS. scissurata Dall 99
SUPERFAMILY ARCACEA 100
Family VII. Arcidce 100
Subfamily Pectunculince '00
Genus Glycymeris Da Costa 100
19. barbarensis Conrad 100
20. septentrionalis Middendorf 101
Suhfamily Arciiice 101
Genus Area (Linne) Lamarck 101
21. labiata SowERBY 101
SUPERFAMILY OSTRACEA 10^
Family VIII. Oslreidce 102
Genus Ostrea (Linne) La m arck 102
22. luiida Carpenter 102
SUPERFAMILY PECTINACEA 103
Family IX. Peclinidoi 103
Genus Peeten Muller 103
Subgenus Pecteu, s. s 103
[S. B.] (P.) bellus Conrad 103
23. (P.) dentatus Sowerbv 104
[S. D.] (P.) hemphilli Dall 105
24. (P.) stearnsii Dall 106
Subgenus Chlamys Bolten 107
Section Patinopecteii Dall 107
25. (P.) cauiinus Godld 107
[8. D.] (P.) expausus Dall 108
Section Nodipecten Dall 108
26. (N.) subuodosus Sowerby 108
Section Chlamys, s. s 109
27. (C.) hastatus Sowerby 109
28. (C.) hericeus GooLD 110
29. (C.) hericeus var. strategus Dall HO
30. (C.) jordaui, sp. nov HI
31. (C.) latiauritus Conrad HI
32. (C.) latiauritus CoNR., var. fragilis, var. nov 112
33. (C.) latiauritus Conr., var. monotimeris Conrad 112
[S. D.] (C.) opuntia Dall 113
Section Plagiocteuium Dall 113
34. (P.) uewsomi, sp. nov 113
[S. D.] (P.) subveutricosus Dall 114
35. (P.) veutricosus Sowerby 114
Subgenus Hiuuitea De France 115
36. (H.) giganteus Gray 115
ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHY OF SAN PEDRO. 73
MOLLUSCA (Continued.)
Family X. Limidce 115
Genus Lima (Bruguiere) Cuvier 115
Subgenus Lima, «. s 115
Section Mantelhim Ad.^m.s 115
37. (M.) dehiseens Cone.4d 116
SUPERFAillLY ANOMIACEA 116
Family XI. Anomiidce 116
Genus Pododesmns Philippi 116
Section Mouia Gr.w 116
38. (M.) macroschisma Deshates 116
Genus Anomia LiNXE 117
39. lampe Gray 117
[S. D.] limatula Dall 118
SUPERFAMIL Y MYTILACEA 118
Family XII. Mytilida: 118
Genus Mytilus (Linne) Bolten 118
Section Mytilus, a. s 118
40. (M.) edulis Linn^ 118
Geuus Septifer Eecluz 119
41. bifurcatus Reeve 119
Genus Modiolus Lamarck 120
Section Modiolus, s. s 120
42. (M.) foruieatus Carpenter 120
43. (M.) rectus Conrad 120
Genus Lithoi^haga Bolten 121
44. plumula Hanlev 121
Order Axomalodesmacea 121
SUPERFAMILY ANA TINACEA 121
Famil;/ XIII. Periplomidce *. 121
Geuus Periploma Schumacher 121
45. argentaria Conrad 121
Family XI V. Thrariidm 122
Geuus Thracia (Leach) Blainvillb 122
46. trapezoides Conrad 122
Family X V. Pandoridce 123
Genus Pandora 123
Subgenus Keunerlia Carpenter 123
47. (K.) bicariuata Carpenter 123
48. (K.) filosa Carpenter 124
Geuus Clidiophora Carpenter 124
49. punctata Conrad 124
Family X VI. Lyonaiidie 125
Geuus Lyonsia TuRTON 125
50. californica Conrad. 125
Gemis Mytilimeria Conrad 125
51. nuttalli Conrad 126
SUPERFAMILY POROMYACEA 126
Family X VII. Verlicordiidie 126
Genus Verticordia S. Wood 126
52. noyemcostata Adams & Reeve 126
Order Teleodesmacea 127
SUPERFAMIL Y ASTARTACEA 127
Family X VIII. Aslartidw 127
Genus Astarte Sowerby 127
Subgenus Crassinella Bayle 127
53. (C.) brauneri, sp. nov 127
SUPERFAMILY CARDITACEA 128
Family XIX. Cardiiidai 128
( 11) ) June 11, 1903.
74 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSC A (Continued).
Genus Venericardia Lamakck 128
54. barbareusis Stearns 128
55. veutricosa Gould 128
Genus Lazaria Conrad 129
56. Bubquadrata Carpenter 129
SUPEBFAMILY CHAMACEA 130
Family XX. Chamidce 130
Genus Chama (Pliny) Linne 130
57. exogyra Conrad 130
58. pellucida Sowerby 130
SUPERFAMILY LUCINACEA 131
Family XXI. Lucinidie 131
Genus Lucina Brcgdiere 131
59. acutilineata Conrad 131
60. califoruica Conrad 132
61. nuUalli Conrad 132
62. tenuisculpta Carpenter 133
Family XXI I. Diplodonlidce 133
Genus Diplodouta 133
Section Diplodouta, s. s 133
63. (D.) orbella GooLD 134
64. (D.) serricata Eeeve 134
Family XXIII. Cryptodontidas 135
Genus Thyasira Leach 135
65. bisecta Conrad 135
66. gouldi Philippi 135
SUPERFAMILY LEPTONACEA 136
Family XXI V. Leptovidu; 136
• Genus Bornia Philippi 136
67. retifera Dall 136
Genus Kellia Tprton 136
Section Kellia Turton, s. s 136
68. (K.) laperousii Desha yes 137
69. (K.) suborbicularis Montagu 137
Family XX I'. KellidUdm 138
Genus Aligena H. C. Lea 138
70. cerritensis, sp. nov 138
SUPERFAMILY CARDIACEA 138
Family XX VI. Cardiidce 1 38
Genus Cardium (Linne) Lamarck 138
Subgenus Trachy cardium Morch 138
71. (T.) quadrigenarium CoNEAD 139
Subgenus Eiugicardium Fischer 139
72. (E.) procerum Sowerby 139
Subgenus Cerastoderma Morch 140
73. (C.) coibis Martyn 140
Subgenus LsBvicardium Swainson 140
74. (L.) elatum Sowerby 141
75. (L.) substriatum Conrad 141
Genus Protocardia Beyrich 142
76. centifilosa Carpenter 142
SUPERFAMILY VENERACEA 142
Family XX VII. Veneridce 142
Subfamily Venerince 142
Genus Tivela Link 142
77. crassatelloides Conrad 143
Genus Callista PoLi 143
78. newcombiana Gabb 143
79. subdiaphana Carpenter 144
80. subdiaphana Carpenter, var. pedroana, var. nov 144
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 75
MOLLUSCA (Continued).
Subgenus Amiantis Conrad 145
81. (A.) callosa Conrad 145
Subfamily Dosinince 146
Geuus Dosinia Scopoli 146
[S. D.] ponderosa Gray 146
Genus Venus Linne 146
[S. B.] perlamiuosa Conrad 146
Subgenus Chioue Megerle 147
82. (C.) fluctifraga SowERBY 147
83. (C. ) gnidia Sowerby 147
84. (C.) neglecta Sowerby 148
85. (C.) simillima Sowerby 148
86. (C.) succincta Valenciennes 149
Subfamily Tapetin<^ 149
Genus Tapes Megerle 149
87. lacineata Carpenter 150
88. staminea Conrad 150
89. teuerrima Carpenter 151
Genus Saxidomns Conrad 151
90. arat us Gould 151
Subfamily Gemminm 152
Genus Psephis Carpenter 152
91 . salmonea Carpenter 152
92. tautilla Gould 153
Family XX VIII. Cooperellidce 153
Geuus Cooperella Carpenter 153
93. subdiaphana Carpenter 153
Family XXIX. Petricolidai 154
Genus Petricola Lamarck 154
Section Petricola Lamarck, s. s 154
94. (P.) carditoides Conrad 154
Section Rupellaria Fledrian 155
95. (R.) lamellifera Conrad 155
Section Petrioolaria 155
96. (P.) denticulata Sowerby 155
97. (P.) cognata C. B. Adams 156
SUPERFAMILY TELLINACEA 156
Family XXX. Tellinidce 156
Geuus Tellina Linn^ 156
Subgenus Moerella Fischer 156
98. (M.) salmonea Carpenter 157
Subgenus Angulus Megerle 157
99. (A.) buttoni Dall 157
100. (A.) bodegeusis Hinds 158
101. (A.)id£eDALL 158
102. (A.) rubescens Hanlet 159
Geuus Metis H. & A. Adams 160
103. alta Conrad 160
Genus Macoma Leach 160
Subgenus Macoma, s. s 161
104. (M.) calcarea Gmelin 161
105. (M.) indentata Carpenter 161
106. (M.) inquiuata Deshayes 162
107. (M. ) nasuta Conrad 163
108. (M.) nasuta Conrad, var. kelseyi Dall 164
109. (M.) seota Conrad 164
110. (M.) yoldiformis Carpenter 165
Family XXXI. Semelida Schumacher 165
76 CALIFOENIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
Genus Semele 165
111. decisa CoNR.\D 165
1 12. pulchra Sowerey 166
113. pulchra Sowerey, var. mouteieyi, var. uov 166
Genus Cumiugia Sowerey 167
1 14. californica Conrad 167
Family XXXII. Psatnmohiidie.. . . 167
GeuTis Psammobia (L.\marck) Bowmen 167
Subgenus Psammobia, s. s 167
115. (P.) eilentula Gabb 168
Genus Sanguinolaria Lamarck 168
Section Nuttallia Dall 168
116. (N.) nuttalli Conrad 168
Genus Tagelus Gray 169
117. californianus Co.nrad 169
Family XXX I II . Donacidm 169
Genus Donax (Linne) Lamarck 169
1 18. californica Conrad 170
1 19. l^vigata Deshayes 170
SUPERFAMIL Y SOLENACEA 171
Family XXXIV. Solenidce 171
Genus Solen Linne 171
120. rosaceus Carpenter 171
121. sicarius Gooi.D 172
Genus Siliqua Megerle 172
122. lucida Conrad 172
123. patula Dixon, var. nuttalli Conrad 173
SUPERFAMILY MACTRACEA 174
Family XXX V. Maclridai 174
Subfamily Mactrinte 174
Genus Mactra Linne 174
124. californica Conrad 174
125. exoleta Gray 175
126. hempbilli Dall 175
Subgenus Spisula Gray 175
127. (S.) catilliformis Conrad 176
128. (S.) falcata Gould 176
Subfamily Pieropsidince 177
Genus Labiosa (Schmidt) Moller . . 177
Subgenus Rseta Gray 177
129. (R.) uudulata Gould 177
Subfamily Lulrariiiiat 178
Genus Tresus Gray 178
130. nuttalli Conrad 178
SUPERFAMILY MYACEA 179
Family XXX VI. Myacidce 179
Genus Platyodon Conrad 179
131. cancellatus Conrad 179
Genus Cryptomya Conrad 179
132. californica Conrad 180
Fainily XXX VII. Corhulidie 180
Genus Corbula (BROoniiiRE) Lamarck 180
133. hitcola Carpenter 181
Genus Nesera Gray 181
134. pectinata Carpenter 181
Family XXX VIII. Saxicavidw. 182
Genus Panopea Menard 182
135. generosa Goold 182
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OP SAN PEDRO. 77
MOLLUSCA (Continued).
Genus Pauomya Gray 183
136. ampla Dai.l 183
SUPERFAMILY ADESMACEA 183
Family XXXIX. Pholadldte 183
Subfamily Pholatlinae 183
Genus Zirphaja Leach 183
137. gabbii Tryon 184
Subfamily Jouanni'tinii- 18*
Geuus Pboladidea Goodall 184
Subgenus Pboladidea, s. » 184
Section Peuitella Valenciennes 184
13S. (P.) penita Conrad 184
CLASS VL SCAPHOPODA 185
Order Solenoconchia 185
Family XL. Dcnlaliida: 185
Genus Deutalium Linne 185
139. hexagonum Sowerby 185
140. iudiauorum Carpenter 186
141. pseudobexagouum Dall 186
142. semipolitum Broderip & Sowekby 187
Genus Cadulns Philippi 187
143. nitentior Carpenter 187
CLASS VII. GASTROPODA 188
Order Opisthoeranciiiata 188
Family XLI . Actaoiiidce 188
Geuus Actteou Montfort ._ 188
144. traskii Stearns 188
Subgenus Riclaxis Dall 188
145. (R.) punctocoelata Carpenter 189
Family XLI/. Tornatinidie 189
Genus Tornatina A. Adams 189
146. cerealis Gould 189
147. culcitella Gould 190
148. eximia Baird 190
149. barpa Dall 191
Genus Volvula A. Adams 191
150. eylindrica Carpenter 191
Family XLI II . Scaphandridce 192
Genus Cylicbna Loven 192
151. alba Brown 192
Family XLI V. Bullidm 193
Genus Bulla Linne 193
152. punctulata A. Adams 193
153. quoyl Gray 193
Genus Haminea Leach 194
154. virescens Sowerby 1 94
Order Pulmonata 194
Suborder Stylo mmatophora 194
SUPERFAMILY MONOTREMATA 194
Family XL V. Helicidm 194
Genus Helix Linne 194
Subgenus Epiphragmophora Strobel 194
155. (E.) sp. indet 195
SUPERFAMILY HYGROPHILA 195
Family XL VI. Limnoiidce 195
Subfamily Planorbince 195
Geuus Planoibis Guettard 195
156. tumidus Pfeiffer 195
157. vermiculaiis Gould 195
78 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
Family XL VII. Physkhe 196
Genus Physa Dkaparnauu 19(i
158. heterostropha Say 196
SUPERFAMIL Y DITREMA TA 196
Family XL VIII. Auriculida 196
Subfamily Melampince 196
Gemis Melampiis Montfort 196
159. olivaceus Carpenter 197
SUPERFAMILY PETROPHILA 197
Family XLIX. Gadiniidce 197
Genus Gadiuia Gray 197
160. reticulata Sowkrby 197
SuPEROKDER StREPTONEURA 198
Order Ctenobranchiata 198
SUPERFAMILY TOXOGLOSSA 198
Family L. Terebridre 198
Genus Terebra Bruguiere 198
Section Acus (Humphrey) Gray 198
161. (A.) simplex Carpenter 198
Family LI. Conidce 199
Genus Conus Linne 199
162. ealifornicus Hinds 199
Family LI I. Pleu rotomidte 1 99
Genus Pleurotoma Lamarck 199
163. perversa Gabb 200
Subgenus Borsonia Bellardi 200
164. (B.) bartschi, sp. uov 200
165. (B.) dalli, sp. nov 201
166. (B.) booveri, sp. nov 201
Subgenus Leucosyriux Dall 202
167. (L.) pedroaua, sp. nov 202
Subgenus Geuota Adams 202
Section Dolichotoma Bellardi 202
168. (D.) carpenteriaua Gabb 202
169. (D.) cooperi, sp. nov 203
170. (D.) tryoniana Gabb 203
GenusDrillia Gray 204
171. cancellata Carpenter 204
172. hemphilli Stearns 204
[S. D.] incisa Carpenter 205
173. inermis Hinds 205
174. inermis, var. penicillata Carpenter 205
175. johnsoni, sp. nov 206
176. merriami, sp. nov 207
177. montereyensis Stearns 207
178. pudica Hinds 208
179. renaudi, sp. nov 208
180. torosa Carpenter 209
Genus Bela Gray 209
181. fidicula Gould 209
182. sanctfe-moniciB, sp. nov 210
Genus Mangilia (Leach) Kisso 210
Subgenus Clatburella Carpenter 210
183. (C.) couradiana Gabb 210
Subgenus Cytbara Schumacher 211
184. (C.) branueri, sp. uov 211
Subgenus Mangilia Ris.so, s. s 211
185. (M.) augulata Carpenter 212
186. (M.) hooveri, sp. nov 212
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 79
MOLLUSCA (Continued).
187. (M.) iuteifossa var. pedroana, var. uot 213
188. (M.) interlirata Stearns 213
189. (M.) oldroydi, sp. uov 213
190. (M.) painei, sp. uov 214
191. (M.) sculpturata D.4LL 214
192. (M.) striosa 0. B. Adams 215
Subgenus Tarauis Jeffreys 215
193. (T.) strongi, sp. iiov 215
Subgenus Siiirotropsis Sars 216
194. (S.) Pleurotoma smithi, sp. uov 216
Family Lll I . CanceUarud(e 217
Geuus Caucellaria Lamarck 217
Subgenus Cancellaria, s. s 217
195. (C.) cooperi Gabb 217
196. (C.) orawfordiana Dall 217
197. (C.) tritonidea Gabb 218
Genus Admete Moller 219
198. gracilior Carpenter 219
Family LI V. Olividce 219
Genus Olivella Swainson 219
199. biplicata Sowerby 219
200. iutorta Carpenter 220
201. pedroana Conrad 221
Family L V. MargincUidce 221
Geuus Margiuella Lamarck 221
202. jewettii Carpenter 221
Section Vol variua Hinds 222
203. (V.) varia Sowerby 222
Family L VI. Mitridte 222
Geuus Mitra Lamarck 222
204. maura Swainson 222
Geuus Mitromorpha A. Adams 223
205. filosa Carpenter 223
206. intermedia, sp. nov 223
Family L VII. Fasciolariida: 224
Subfamily Fusime 224
Genus Fusus Lamarck 224
207. barbarensis . Trask 224
208. luteopictus Dall 225
209. robustus Trask 226
210. rugosus Trask 226
Genus Pisauia Bivona 227
211. fortis Carpenter 227
Family L VIII Biiccinidm 227
Genus Chrysodomns Swainson 227
212. rectirostris Carpenter 228
213. tabulatus Baird 228
214. sp. indet 229
Genus Sipboualia A. Adams 229
215. kellettii Forbes 229
Geuus Macron H. & A. Adams 230
216. kellettii A. Adams 230
217. lividus A. Adams 230
Family LIX. Nassidie 230
Genus Nassa Lamarck 230
218. califoruiaua Conrad 231
219. cerriteusis, sp. nov 231
220. fossata Gould 232
221. insculpta Carpenter 233
80 CALIFOENIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
■222. meudica Gould 233
223. meudica Gould, var. cooperi Forbes 234
224. perpinguis Hinds 234
225. tegula Reeve 235
226. versicolor C. B. Adams, var. hooveri, var. uov 2,36
Family LX. Cobnnhcllithie 236
Genus Columbella L.4marck 236
227. solidula Reeve, var. pra^cursor, var. uov 236
Subgenus Anachis H. & A. Adams 237
22S. (A.) minima, sp. uov 237
Subgenus jEsopus Gould 237
229. (iE.) chrysalloidea Carpenter 237
230. (.S;.) oldroydi, sp. uov 238
Subgenus Astyris H. & A. Adams 238
231. (A.) califoruiaua Gaskoin. 238
232. (A.) gausapata Gould 239
233. (A.) gausapata Gould, var. carinata Hinds 240
234. (A.) tuberosa Carpenter 240
Genus Amphissa H. & A. Adams 241
235. corrugata Reeve 241
236. ventricosa, sp. uov 242
237. versicolor Dall 242
Fa7nUy LX/. Murkithx ' 243
Genus Murex Linne 243
Subgenus Chicoreus Montfort 243
238. (C.) leeanus Dall 243
239. (C.) trialatus Sowerby 243
Subgenus Pteronotus Swainson 244
240. (P.) festivus Hinds 244
Subgenus Pterorhytis Conrad 244
241. (P.) foliatus Martyn 245
242. (P.) nuttalli Conrad 245
243. (P.) mouoceros Sowerby 246
Genus Mouoceros Lamarck 246
244. engonatum Conrad 246
245. lapilloides Conrad 247
Genus Chorus Gray 247
246. belclieri Hinds 247
Genus Euplenra H. & A. Adams 248
247. muriciformis Broderip 248
248. muriciformis, var. curta, var. uov 249
Genus Trophou Montfort 249
Subgenus Boreotrophou Fischer 249
249. (B.) cerritensis, sp. uov 249
250. (B.) gracilis Perry 250
251. (B.) multicostatus EsniscHOLTZ 251
252. (B.) pedroana, sp. uov 251
253. (B.) scalariformis Gould 252
254. (B.) stuarti Smith 252
255. (B.) orpheus, var. praacursor, var. uov 253
256. (B.) tenuisculptus Carpenter 253
257. (B.) triaugulatus Carpenter 254
Geuus Ocinebra Leach 254
258. barbareusis Gabb 254
259. foveolata Hinds 255
260. interfossa Carpenter 255
261. keepi, sp. uov 256
262. lurida Middendorff 256
263. lurida Midd., var. aspera Baird 257
ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDKO. 81
MOLLUSCA (Continued).
264. lurida Midd., var. cancellina Philippi 257
265. lurida Midd., var. cerritensis, rar. dot 258
266. lurida Midd., var. munda Carpenter 258
267. micheli Ford 259
268. perita Hinds 259
269. poulsoui NnxTALL 260
Subfamily Purpurinm 260
Genus Purpura Beuguiere 260
270. crispata Chemnitz 261
271. saxicola Valenoienne.s 261
Subfamily Coralliophilince 262
Genus Coralliophila H. & A. Adams 262
272. nux Reeve 262
Suborder Streptodonta 262
SUPERFAMILY PTENOOLOSSA 262
, Family LXII. SeaUdce 262
Genus Scala Humphrey 262
273. bellastriata Carpenter 263
274. erebricostata Carpenter 263
275. hemphilli Dall 264
276. hindsii Carpenter 264
277. indianorum Carpenter 264
278. tincta Carpenter 265
Genus Opalia H. & A. Adams 266
[S. D.] anomala Stearns 266
279. borealis Gould 266
280. crenatoides Carpenter, var. insculpta Carpenter. .. . 267 [S. D.] varicostata Stearns .' 267
SUPERFAMILY GYMNOGLOSSA 268
Family LXI 1 1. Eulimidte 268
Genus Eulima Eisso 268
281 . falcata Carpenter 268
282. hastata Sowbrbt 268
283. micans Carpenter 269
Family LXI V. Pyramidellidm 269
Genus Turbonilla Risso 269
Section Strioturbonilla Sacco 270
284. (S.) muricata Carpenter 270
285. (S.) similis C. B. Adams 270
286. (S.) stearnsii Dall & Bartsch, sp. uov 271
287. (S.) torquata Gould 271
288. (S.) torquata var. stylina Carpenter 272
Section Lanoea Pease 272
289. (L.) aurautia Carpenter 272
290. (L.) tridentata Carpenter 273
291. (L.) peutalopha Dall & Bartsch, sp. nov 274
Section Pyigiscus Philippi 274
[S. D.] (P.) auricoma Dall & Bartsch, sp. nov 274
292. (P.) latifuudia Dall & Bart.sch, sp. nov 275
293. (P.) teuuicula Gould 275
294. (P.) crebriHlata Carpenter 276
295. (P. ) subcuspidata Carpenter 277
Section Pyrgisoulus Monterosato 277
296. (P.) laniinata Carpenter 277
Section Pyrgolampros Sacco 278
297. (P.) lowei Dall & Bartsch, sp. nov 278
[S. D.] (P.) lowei var. pedroaua Dall & Bartsch, var. nov. . 279
298. (P.) arnoldi Dall & Bartsch, sp. nov 279
299. (P.) gibbosa Carpenter 279
( 11 ) June 16, 1903.
82 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
300. (P.) adleri Dall & Bartsch, sp. nov 280
Geuus Pyramidella Lamarck 280
301. (P.) oonica var. variegata Carpenter 280
Geuus Odostomia Fleming 281
Section Odostomia (Fleming) s. s 281
302. (0.) tenuis Carpenter 281
Section Evalea A. Adams 281
[S. D.] (E.) stearnsii Dall & Bartsch, sp. nov 282
303. (E.) gouldii Carpenter 282
Section Amaura Moller 282
[S. D.] (A.) pupiformis Carpenter 283
304. (A.) uuciformis Carpenter, var. avellana Carpenter. 283 Section Chrysallida Carpenter 283
[S. D.] (C.) diegensis Dall & Bartsch, sp. nov 284
Section Oscilla A. Adams 284
[S. D.) (O.) aaquisculpta Carpenter 284
[S. D.) (0.) gramniatospira Dall & Bartsch, sp. nov 285
Subgenus Ivara Dall & Bart.sch, subgen. nov 285
305. (I.) terricula (Carpenter) Dall & Bartsch 285
SUPERFAMILY TMNIOGLOSSA 285
Family LX V. Trilonidw 285
Genus Tritonium Link 285
306. gibbosus Broderip 286
Subgenus Priene H. & A. Adams 286
307. (P.) oregonensis Redfield 286
Geuus Ranella Lamarck 287
308. californica Hinds 287
Family LX VI. Cypraida 288
Genus Cypriea LiNNfi 288
309. spadicea Gray 288
Genus Trivia Gray 288
310. californica Gray 288
311. solandri Gray 289
Genus Erato Risso 289
312. columbella Menke 289
Family LX VII. Triforidm 290
Genus Triforis Deshayes 290
313. adversa Montagu 290
SUPERFAMILY CERITHIACEA 290
Family LX VIII. Cerilhiopsidce 290
Genus Seila A. Adams