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 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)) 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 290 314. assimilata C. B. Adams 290 Family LXIX. Cerithiidm 291 Genus Bittium Leach 291 315. asperum Gabe 291 316. californicum Dall & Bartsch 291 317. filosum Gould 292 318. quadrifilatum Carpenter (with evolutionary discus- sion of several species) 292 319. rugatum Carpenter 295 320. williamsoni, sp. nov 295 Subgenus Styliferina A. Adams 295 321. (S.) tenuisculpta Carpenter 296 Genus Diastema Deshayes 296 322. sp. indet 296 Genus Cerithidea Swainson 296 323. californica Haldemann 296 Family LXX, Ccecidx 297 Arnold— THK paleontology and stratigraphy of san pedro. 83 MOLLUSCA (Continued). Genus Csecum Fleming 297 324. californiciim Dall 297 325. crebricinctum Carpenter 298 326. magnum Stearns 298 Family LXXI. Vermelidce 299 Genus Serpulorbis Sassi 299 327. squamigerus Carpenter 299 Subgenus Vermicularia Lamarck 299 328. (V.) sp. indet 299 Genus Spiroglyphus Dacdin 299 329. lituella Morch 299 Family LXXU. Turrilellida: 300 Genua Turritella Lamarck 300 330. cooperi Carpenter 300 331. jewettii Carpenter 300 Family LXXI II. Litlorinidce 301 Genus Littoriua Ferd.ssac 301 332. planaxis (Nuttall) Philippi 301 333. scutulata Gould 302 Genus Lacuna Turton 302 334. compacta Carpenter 302 335. porrecta Carpenter 303 336. solidula (Loven) Carpenter 303 Family LXXI V. Fossaridm 304 Genus Fossarus Philippi 304 Subgenus Isapis H. P. callha Uorallum 5 in or ^^,j^^ ^^ in. /.32 in more in height; nve J ' ' complete cycles of j glabrous, subequal costaa, distinct to base, ^ ^ P^ I near base every fourth or sixth costa more ; P. slearnsi { prominent; axes of calice, .72 in. /.50 iu . . . . ) i^ora nm ori y ._ n. i Q^g^.g feeble, except near calicular margin. / „ i -i- in height; four com- diameter of circular calice, .22 in ^- ^«»"'" plete cycles of septa. ( ) According to the diagnostic characters given by Verrill, these three species are very distinct. 4. Paracyathus pedroensis Vaughan, sp. nov. Plate III, Figs. 1 and la. Corallum subturbinate in shape, base damaged, apparently not especially expanded; trans- verse outline of calice elliptical, slightly deformed. Costse not prominent, but distinct from the calicular margin to the base, subequal, some- times every third or every fifth may be slightly more prominent than those intervening, the edges usually flattish, sometimes slightly crested. Bottoms of the intercostal furrows usually flattish; granulations crowded on the costse, and present in the intercostal furrows also. 1 Proc. Boat. Soc. Nat. Hist., Vol. XII, 1869, p. 394; Trans. Conn. Acad. 8ci., Vol. I, 1870, p. 637, Pi. IX, figs. 9, 9a. " Proc. Bost. Soc. Nat. Hist.. Vol. XII, 1869, p. 393; Trans. Conn. Acad. Sci., Vol. I, 1870, p. 537. 'Trans. Conn. Acad. Sci., Vol. I. 1870, p. 638. * These decimals of an inch can be computed into millimeiers by reckoning ,1 inch = 2.6_mm. ARNOLD— THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDKO. 89 There are four complete cycles of septa, and many members of the fifth, but the fifth is not complete. The septal margins project very slightly above the upper margin of the corallum wall; the margins of the members of the first and second cycles, and those of the third cycle when members of the fifth are present, are slightly more prominent than the margins of the members of the higher cycles. The septal faces are densely granulated, and the granulations show a decided tendency toward elongation along the courses of the septal trabecule. The septa are crowded, those of the first, second, and third cycles are thick and strong; when members of the fifth cycle are present those of the fourth are quite thick, but are thinner than the older septa. The pali are well developed, and are shown in great perfection on the type specimen. They are broad and simple, and not bilobed. Those before the septa of the first cycle are the nar- rowest; those before the septa of the second cycle are slightly wider, and those before the septa of the third cycle are still wider. The inner margins of the pali before the septa of the first, second, and third cycles form a crown bordering the outer edge of the columella. In those half or quarter sys- tems in which septa of the fifth cycle are present, pali stand before the members of the fourth cycle. These pali are large, but stand back from the columella. In such cases the pali join the members of the fourth cycle to the sides of the included members of the third. When no pali are present the members of the fourth fuse by their inner margins directly to the side of the included member of the third. When members of the fifth cycle are present, they curve toward the included member of the fourth. There are no pali before the youngest septa in any given system. Margins of the pali entire. The calice is shallow, widely open Its ends, corresponding to the ends of the longer trans- verse axis, are very slightly depressed. The upper surface of the columella is flat; it consists of the rounded upper terminations of a large number of papillee. The pali, excepting those of the fourth cycle, form a crown around the columella, as has already been stated. Dimensions. — Greater diameter of calice, 12 mm.; lesser diameter of calice, 10 mm.; height of corallum, i8-|- mm. Locality. — San Pedro, California. Geologic Horizon. — Pleistocene. Type. — From the collection of Ralph Arnold. If the description first given is compared with the table showing the chief diagnostic features of Verrill's species, it will be evident that the only species with which comparison needs to be made is P. stearnsi. At the same time, certain strik- ing differences between the two will be very evident. The first is one of size. p. stearnsi. . . P. pedroensis Greater Diameter of Calice. 18mm. 12 mm. Lesser Diameter of Calice. 12.5 mm. 10 mm. Height of Corallum. 12.5 mm. 18-f- mm. The costje and the number of septa are different in the two species, but a much more important difference has not yet been brought out in the discussion. Verrill says of the septa and pali in P. stearnsi: "The primary and secondary septa are considerably broader than the others, broadly rounded and somewhat exsert at summit, narrowed toward the base, and divided into tivo or three unequal, broad, stout, paliforvi teeth, which are rough and lacerately spinulose at summit " ' 1 The italics are used by the author of the prefient paper. , 12 ) October 28, 1902. 90 CALIFOENIA ACADEMY OF SCIENCES. As stated in the present description, the pali of P. pedroensis are not lohecl and their margins are entire. These comparisons will show how strikingly different the present species is from any of those previously described species from the west coast of North America. ECHINODERMATA. Class ECHINOIDEA/ Subclass EUECHINOIDEA. Order DIADEM ATOI DA. Suborder STEREOSOMATA. Family II. ECHINOMETRID^E. Genus Strongylocentrotus Brandt. Test symmetrical and polyporus. Amb straight, broad at the ambitus and peristome, and with broad, poriferous zones. Pairs of pores in oblique arcs, or almost transverse series of from four to ten pairs, and crowded actinally. Interporiferous areas with two vertical rows of plain, imperforate primary tubercles ; secondaries and miliaries also present. Amb with two rows of primary, and four or more of secondary tubercles. 5. Strongylocentrotus franciscanus A. Agassiz. Toxocidaris franciscana A. Agassiz, Bull. Mus. Comp. Zool., Vol. i, 1863 ijide Clark.) This is the large sea-urchin of the West Coast. Spines which are probably of this species have been found in tlie lower San Pedro series of Deadman Island. The spines of this species are distinguishable by their large size and longitudinal striations. Some of the spines found are 20 mm. long and o mm. in diameter. Living. — Puget Sound; San Diego (H. L. Clark). Pleistocene. — San Pedro (Arnold). 6. Strongylocentrotus purpuratus Siimpson. Echinus purpuraius Stimpson, Crustacea and Echinoderms of the Pacific Coast, 1857 {,fide Clark.) Numerous spines of this small purple sea-urchin have been found in the San Pedro series. No part of the test has ever been discovered in these deposits, to the writer's knowledge. Several nearly perfect tests of this species were found in the * The classlficatiou auU geueric descriptious for tblsclaes are ftoui Eaetmau iu Zittel's Text Book of Paleoutology. ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 91 Pleistocene (lower San Pedro series) deposits at the bath-house, Santa Barbara. A nearly perfect test was also found in the upper horizon of the San Diego formation ( Pleistocene (?) at Pacific Beach, near San Diego. Living. — San Francisco; Puget Sound (H.L.Clark): San Pedro (Arnold). Pleistocene. — San Pedro; Santa Barbara; San Diego (Arnold). Order CLYPEASTROIDA. Family III. SCUTELLIDiE. Genus Scutella Lamarck. Test circular or subcircular in outline, sometimes undulating or notched, broadest behind ; petaloid parts of the amb unequal, well developed, nearly closed. Peristome small, central, subcir- cular. Periproct very small, inframarginal. Apical system central, more or less pentagonal. Subgenus Echinarachnius Leske. Apical system eccentric in front or behind. Periproct actinal, marginal or supramarginal. 7. Scutella (Echinarachnius) excentricus Eschscholtz. Scutella excenUica EscH., Zool. Atlas, PI. XX, fig. 2, 1826. Echinarachnius excentricus EscH., Valenciennes, Voyage Venus, PI. X, i9i^6;^=Scutella siriaiula Con. {Jide Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 271). Merriam, Bull. Dept. Geol., Univ. of Cal., Vol. II, 1898, p. no; Proc. Cal. Acad. Sci., 3rd Ser., GeoL, Vol. I^ 1899, p. 170, PI. XXII, fig. 8. Test quadrate-oval in outline ; upper surface arched, summit behind the middle of the long diameter, but in front of the excentric apical system ; petals broad, open at ends ; posterior laterals wide apart, ovate in outline, one-half the length of the anterior pair ; anterior petal longer than the anterior laterals, scattered pores continue some distance beyond the end ; apical shield excentric, its distance from the posterior margin being to its distance from the anterior margin as i to 1.8+ : the ambulacral furrows are split up into a great number of small branches, of which the strongest pass over the margins and extend over the upper surface ; four of the strongest furrows run to the lateral petals and stretch through their median areas almost to the apical system ; those furrows not passing to the petals sometimes reach half way to the apical system. Dimensions. — Long. 63 mm.; lat. 68 mm.; alt. 8 mm. Specimens from the lower San Pedro series of Deadraan Island, and upper San Pedro series of San Pedro and Los Cerritos w^ere submitted to Dr. Merriaiu, who pronounced them typical E. excentricus. This is the common "Sand Dollar" of the Pacific Coast. Living. — Alaska to San Pedro (Cooper). Pleistocene. — San Pedro (Cooper; Arnold) : San Diego; Santa Barbara (Arnold) (?) Pliocene. — Seven Mile Beach, San Mateo County; San Fernando; (?) San Diego (Cooper): (?) San Gregorio Creek, San Mateo County (Barber). 92 CALIFORNIA ACADEMY OF SCIENCES. MOLLUSCOIDEA. Class BRYOZOA. 8. Bryozoa sp. indet. Small pieces of branching bryozoa are found quite abundantly in the San Pedro series; but as no diagnoses of West Coast species are available, their generic and specific relations cannot be given. Among some material sent to Dr. Dall, and identified by him, were several specimens which he labeled '■'CiqyuUfera sp." These little saucer-shaped bryozoa are from the upper San Pedro deposits, at the lumber- yard, north end of the San Pedro bluff. Class BRACHIOPODA.' Order ARTHROPOMATA. Family IV. TEREBRATULIDvE. Genus Terebratalia Bcecher. Shell smooth or radially plaited; dorsal valve longitudinally impressed; hinge-line straight or not much curved; beak with a flattened area on each side of the deltidium; foramen large; del- tidium incomplete; loop attached to the septum. IWebratalia obsoleta Dall is a characteristic species. [S. B.y Terebratalia hemphilli Dull. Plate XVII, Figs. 1, 2 and 3. Terebratalia hemphilli Dall (mss.) Shell of medium size, subcircular in outline, rather thin ; brachial valve with mesial flexure concave ; surface of this valve sculptured by numerous fine incremental lines, and very faintly near the apex by several radiating lines ; pedicle valve mesially convex, the sculpture being as in the brachial valve. Dimensions. ^V^on^. 56 mm.; lat. 57 mm.; diam. 30 mm. This species may be distinguished from T. mntlii by its broader outline, larger foramen, and nearly smooth surface. T. hemphilli is a form which shows much variation both as regards its outline, degree of convexity or concavity of its valves, and its sculpture. The drawings of this species were made by Mr. J. Howard Wilson, who first discovered the species. Found in the Pliocene of Packard's Hill, Santa Barbara. FlioceMe. — Santa Barbara (Wilson; Arnold). ^ The claeaificatlon and generic description of this class are from Tryon's *' Structural and Systematic Conchology." - All species described in this paper, but not occurring in the 8an Pedro fauna, are designated by the initials of the locality from whence they are described. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 93 9. Terebratalia smithi, sp. nov. Plate XVII, Fio. 9. Shell of medium size, subcircular in outline, rather thin ; brachial valve with mesial flexure concave, surface of this valve sculptured by about thirty small, rounded, radiating ridges and several prominent incremental lines ; intermediate incremental lines small and inconspicuous ; pedicle valve quite strongly mesially convex, the surface being sculptured as in the dorsal valve ; beak with a flattened area on each side of the deltidium ; foramen small. At a length of 20 mm. and before, the shell is slightly broader proportionately than in the adult. Dimensions. — Long. 50 mm.; lat. 47 mm.; diam. 23 mm. T. smithi resembles T. hemphiUi Dall (mss.), but differs from that species by being much narrower in all stages of growth, liaving a much smaller foramen, and in being much more prominently sculptured. A large series of T. hemphiUi collected from the Pliocene at Santa Barbara by Mr. J. Howard Wilson was compared with the type of T. smithi, and the specimens in every case showed the differences men- tioned above. The drawings of T. hemphilli (PI. XVII, figs. 1, 2, 3) were made by Mr. J. Howard Wilson from a specimen obtained at Santa Barbara, and are inserted here for comparison with the figure of the type specimen of T. smithi. T. hemphilli has been found so far only in the Pliocene of Santa Barbara. This species and Laqueus jeffreysi are the only brachiopods which have so far been found in the San Pedro beds. The type specimen, the only one found, was obtained by Mrs. Oldroyd from the Pliocene of Deadman Island; it is figured in this paper, and is now in the collection of Mrs. Oldroyd. Pliocene. — San Pedro (Oldroyd). Genus Laqueus Dall. Shell with the reflected portion of the loop attached by slender processes, on each side, to the haemal processes, at or near the points where the two septal processes branch off to the septum; foramen complete. Type, Laqueus californicus Koch. 10. Laqueus jeffreysi Dall. Frenula jeffreysi Dall, Am. Nat., Vol. V., 1871, p. 55 (ismeniform stage). Ismejiia jejfreysi Dall, Am. Jour. Conch., Vol. VII, 1871, p. 65, PI. XI, figs. 7-10. Megerlia j^t/ffreysi Dall, Sci. Res. Expl. Alaska, 1877, p. 48. Laqueus californicus var. va7ico2tverensis Davidson, Mon. Rec. Brachiopoda, Trans. Linn. Soc. , 2nd Sen, Vol. IV., 1887, p. 113, PI. XVIII, figs. 10-13^ (adult), {fide Dall). Laqueus Jeffrey siViPOA., Proc. U. S. Nat. Mus., Vol. XVII, 1894, p. 725. Shell subcircular, inflated, with the margins of the valves nearly straight ; surface smooth, waxen, with close, conspicuous punctations ; area marked by an incised line ; deltidia wanting ; the two separated parts of the area narrow and very small ; beak of the hremal valve rather prominent, smooth. Neural beak incurved, truncated, not prominent. Dimensions. — Long. 35mm.; lat. 35 mm.; diam. 17 mm. 94 CALIFORNIA ACADEMY OF SCIENCES. Distinguishable externally from L. calif ornicus by thicker shell, waxen rather than ruddy coloration, and larger foramen. Specimen identified by Dr. Dall. Specimens which may be of this species ai"e labeled "Z. calif oi'nicus" in the State Museum collection of fossils at Berkeley. Found in Pliocene of Deadman Island; two specimens, one by Mrs. Oldroyd. Found in Pliocene of Pacific Beach, near San Diego, and also in the Pliocene of Packard's Hill, Santa Barbara. Living. — Aleutian Islands to point off Estero Bay, near San Luis Obispo, (75 to 238 fathoms) Dall. Pliocene. — San Pedro (Arnold; Oldroyd): Santa Barbara; San Diego (Arnold). Family V. LINGULID^. Subfa m ily L I KG UL IN^. Genus Glottidia Dall. Shell linguiform, elongate, pedunculated ; dorsal valve provided internally with two sharp, narrow, incurved laminae, diverging from the beak, and extending about one-third the length of the shell ; ventral valve with a mesial septum of about the same length, extending forward from the beak ; anterior adductor impressions rounded ; scar of post-adductor close in cavity of beak, rounded ; shell smooth, perforate or imperforate. Type, Glottidia alhida Hinds. [S. B.] Glottidia albida Hinds. Lingula albida Hinds, Zool. Sulph., p. 298, PI. XXIX, fig. 4, 1845. G. W. Sowerby, Thes. Conch., p. 393, PI. LVII, fig. 6, 1846. Davidson, Ann. & Mag. Nat. Hist., 2nd Sen, Vol. IX, 1852, p. 377. Reeve, Conch. Icon., Monog. Lingula, PI. I, fig. 4, 1859. E. Suess, Sitz. k. Akad. Wiss. Wien, Bd. XXXVII, 1859, p. 230. Carpenter, Brit. Assn. Rept. 1863, p. 636. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 246. Keep, West Coast Shells, p. 215, fig. 182, 1892. Glottidia albida Hinds, Dall, Am. Journ. Conch., Vol. VI, 1870, p. 157, PI. VIII, figs. 1-6; Proc. Phil. Acad. Nat. Sci. , 1873, p. 204; Scientific Results Expl. Alaska, 1877. Davidson, Challenger Rept. (Zool.) Vol. I, 1880, p. 26; Recent Brachiopoda, Part 3, 1886, p. 221, PI. XXVIII, figs. 2-4. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1893, p. 182. Shell narrow; elongated, oval, linguiform, tapering at the beaks, sides almost subparalleh very slightly curved in front; rather flat, marked with concentric lines of growth; in interior of ven- tral valve the beak is pointed, with a small triangular-shaped thickening grooved along the middle; mesial septum extends for one-third length of valve; scars as in generic description. Dimensions. — Long. 27 mm.; lat. ir mm.; diam. 5.5 mm. One perfect valve and two imperfect valves of this species were found in the Pliocene of Packard's Hill, Santa Barbara. Living. — Monterey to Magdalena Bay, Lower California (Davidson). Pliocene. — Santa Barbara (Arnold): San Diego well (Hemphill). AKNOLD — THE PALEONTOLOGY AND STRATIGBAPHY OF SAN PEDRO. 95 MOLLUSCA. Class PELECYPODA.' Order PRIONODESMACEA. Superfamily NUCULACEA. Family VI. NUCULID.E. Genus Nucula Lamarck. Shell trigonal, with the umbones turned towards the short posterior side; smooth or sculp- tured; epidermis olive; interior pearly; margins crenulated; hinge with prominent internal cartilage- pit, and a series of sharp teeth on each side; pallial line simple. Type, Area nucleus Lam. Subgenus Acila H. & A. Adams. Shell with divaricate sculpture. Niicula divaricaia Hinds is a characteristic species. II. Nucula (Acila) castrensis Hinds. Niicula castrensis Hinds, Proc. Zool. Soc. , 1843, p. 98; Zool. Sulph., p. 61, PI. XVII, fig. 5, 1844. H. &. A. Adams, Gen. Rec. Moll., Vol. II, p. 545. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192. Acila castrensis Hinds {^=A. lyalli BAiRD,yide Carpenter, Brit. Assn. Rept., 1863, p. 644); {^Nucula divaricata CoN.^JV. decisa CoN.=N. co/iradi Meek, /ide Gabb, Pal. Cal., Vol. II, 1869, P" 102). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 227. Williamson, Proc. U.S. Nat. Mus., Vol. XV, 1892, p. 192. Dall, Trans. Wagner Inst. Sci., Vol. Ill, 1898, p. 572. Shell small, trigonal, convex, of medium thickness; umbones posterior to center, turned posteriorly; anterior end longer than posterior, rounded; posterior end short, truncated; surface divaricately sculptured; hinge with prominent internal cartilage- pit and numerous sharp teeth on each side. Dimensions. — Long. 11. 5 mm.; alt. 10 mm.; diam. 8 mm. Easily distinguishable by the liinge teeth and divaricate sculpture. Speci- mens identified by Dr. Dall. Common in Pliocene, rare in lower San Pedro series, of Deadman Island and San Pedro. Livincj. — Sitka to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold). Pliocene. — San Pedro (Arnold) : San Fernando; San Diego well (Cooper). (?) Miocene. — Oregon; Martinez; Griswold's, San Benito County (Cooper): Blakely, near Seattle, Washington (Arnold). 1 The major classiticatiou of this class is according to that presented by Dr. W. H. Dall iu Part III of the " Contributions to the Tertiary Fauna of Florida." The minor details of classificatiou and most of the generic descriptions are from Parts IV and V of the same work. The rest of the generic descriptions are from Tryon's " Structural and Systematic Conchoiogy." 96 CALIFOKNIA ACADEMY OF SCIENCES. Subgenus Nucula s. s. Shell not divaricately sculptured. Kiicnla obliqua Lam. is a characteristic species. 12. Nucula (Nucula) suprastriata Carpenter. Plate XVIII, Fig. 6. (?) Nucula tenuis (iion MoNT.) Carpenter, Brit. Assn. Rept. 1863, p. 644. Cooper, State Mus. Collection Catalogue. Shell small, trigonal, convex, thin, white, pearly interior; utnbones turned toward the short posterior end; posterior end sharply rounded, anterior evenly rounded; surface with numerous dis- tinct, rounded, raised, concentric lines; interior of margin finely crenulated; hinge with small, interior cartilage-pit, and numerous sharp teeth on each side. Dimensions. — Long. 5.8 mm.; alt. 5.2 mm.; diam. 3 mm. This beautiful little shell is easily distingui.shable by its triangular shape, numerous sharp teeth, and distinct concentric sculpture. Specimens identified by Dr. Dall. Rare in the lower San Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series of San Pedro; common in the upper San Pedro series of Los Cerritos. Found also at Spanish Bight, San Diego. The specimen figured is from the upper San Pedro series at Los Cerritos, and is now in the collection of Delos Arnold. (?) Living. — Straits of Fuca to Santa Barbara; Japan (Cooper). Pleistocene. — San Pedro (Arnold): San Diego (Arnold). Family VL LEDID.E. Genus Leda Schumacher. Shell resembling Nucula; oblong, rounded in front, produced and pointed behind; margins even; pallial line with a small sinus; umbonal area with a linear impression joining the anterior adductor. Leda pernula Mull, is a characteristic species. 13. Leda fossa Baird. Plate XVII, Fig. 7. Leda fossa Baird, Proc. Zool. Soc, 1863, p. 71. Carpenter, Brit. Assn. Rept., 1863, p. 644. Dall, Nat. Hist. Soc. British Columbia, Bull, No. 2. 1897, p. 7, PI. II, figs. 3, 13. Shell small, elongate, convex, thin; umbones anterior, turning slightly toward the posterior end, which is elongated, narrow and truncated; anterior end short and evenly rounded; sculpture nearly obsolete, a few concentric lines discernible; escutcheon long, narrow, smooth and deep-set; an elongate process on middle of interior of posterior end; hinge with small internal cartilage-pit, and numerous sharp teeth on each side. Dimensions. — Long. 11 mm ; alt. 6 mm ; diam. 3.8 mm.; umbo to posterior end 7.5 mm.; to anterior end 5 mm. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 97 Distinguishable by lack of sculpture. Specimen identified by Dr. Dall. One specimen from lower San Pedro series of Deadman Island, which is the one figured, and which is now in the collection of Delos Arnold. Living. — Puget Sound (Carpenter). Pleistocene. — San Pedro (Arnold). 14. Leda hamata Carpenter. Plate XVII, Fig. 4. Leda hamala Cpr. , Brit. Assn. Rept., 1863, p. 644. Shell small, elongate-trigonal, convex, thin; umbones anterior, turning slightly toward the posterior end; short, rounded anteriorly; much lengthened, narrowed and abruptly truncated pos- teriorly; surface sculptured by strong, concentric raised lines; a raised band, strongly transversely sculptured by continuations of the concentric ridges, passes from the umbo, around the escutcheon, to the posterior end; on the interior of the posterior end is an elongated, raised process; escutcheon deep-set, smooth. Dimensions. — Long. S mm.; alt. 5 mm.; diam. 2.5 mm.; umbo to posterior end 5.5 mm.; to anterior end 4 mm. A small species, readily distinguishable by its long, curved posterior portion, strong sculpture, smooth escutcheon, and interior posterior process. Specimen iden- tified by Dr. Dall. A nearly perfect, united pair from the lower San Pedro series of Deadman Island; rare; also reported from the Pliocene of Deadman Island. Pleistocene of Spanish Bight, San Diego. The specimen figured is from the lower San Pedro series, and is now in the collection of Delos Arnold. Living. — Santa Barbara to Catalina (Carpenter). Pleistocene. — San Pedro (Arnold): San Diego (Arnold). Pliocene. — Deadman Island, San Pedro (Arnold). 15. Leda minuta Fahr. var. praecursor, var. nov. Pl.\te XVII, Fig. 6. Shell small, trigonal, conve.x, thin; umbones anterior to middle and turning slightly toward the posterior side; anterior portion from umbones short and rounded; posterior portion longer, slightly depressed, produced and slightly truncated; surface sculptured by prominent, raised con- centric lines; escutcheon long, narrow, slightly striated with continuation of concentric ridges; a flat sculptured band runs around escutcheon from umbo to posterior end, and on the interior of the shell at the posterior end of this band is a little elongate ridge or process; hinge with prominent internal cartilage cup and about fifteen prominent sharp teeth on each side; pallial sinus small, narrow. Dimensions. — Long. 7.8 mm.; alt. 5 mm.; diam. 3.9mm.; umbo to posterior end 5 mm.; to anterior end 4 mm. ( 13 ) November 1, 19C'2. 98 CALIFORNIA ACADEMY OF SCIENCES. Distinguishable from L. ttvphria by smaller size, truncated posterior end with process on interior at this end, comparatively coarser sculpture, straighter posterior dorsal margin, and fewer teeth. The type shows two concentric furrows, one at 2.5 mm. and the other at 4 mm. from the umbo, which are probably the result of inter- rupted growth. Specimens identified by Dr. Dall, who pronounced them a variety of Z. minuta Fabr., a northern species. Rare in lower San Pedro series of Deadman Island and San Pedro. The specimen figured is the type, which is from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). i6. Leda taphria Dull. Plate XVII, Fig. 5. Leda taphria Dall, Nat. Hist. Soc. British Columbia, Bull. No. 2, 1897, p. 7, PI. II, figs. 6 and 8 {^ccrlata Hds., 1844, not Conr., \%-i,2\ fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, 1898, P- 579)- Nucjila ctzlaia Hds., Proc. Zool. Soc, 1844, P- 99! Zool. Sulph., p. 64, PI. XVIII, fig. 13, 1844. Leda ccelata Hds., Thes. Conch., Vol. Ill, No. 42, figs. 95, 96. Carpenter, Brit. Assn. Rept., 1863, p. 644. Gabb, Pal. Cal., Vol. II, 1869, p. 103. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 245. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192. Shell small, trigonal, oblong and rounded in front, produced and pointed behind; surface sculptured by numerous sharp, concentric, raised lines; umbones central, turned toward posterior end; escutcheon long, narrow and concentrically striated ; hinge with prominent internal cartilage-pit, and about twenty sharp teeth on each side; pallial line with a small sinus; umbonal area with a linear impression joining the anterior adductor. Dimensions.— \^ong. 19 mm.; alt. 11 mm.; diam. 8 mm. This is the largest of this genus found in these deposits, and is easily recog- nized by its size, sculpture and peculiar teeth. Hinds' name, L. cuJata, was preoccu- pied by a species of Conrad's, and Dall has renamed Hinds' species for that reason. Specimens identified by Dr. Dall. Found in Pliocene of Deadman Island and Timm's Point; lower San Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series of Deadman Island, San Pedro, Crawfi,sh George's, Los Cerritos, and Long Beach. Found also in the Pliocene of Pacific Beach, and in the Pleistocene of Spanish Bight and Pacific Beach, San Diego. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Bodega Bay to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; San Diego (Arnold). Pliocene. — San Fernando; San Diego well (Cooper): San Pedro; San Diego (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 99 Miocene. — Walnut Creek, Contra Costa County; Griswold's, San Benito County; San Juan Capistrano, San Diego County (Cooper). Genus Yoldia Moller. Shell oblong, slightly attenuated behind; compressed, gaping, smooth or obliquely sculp- tured, with a dark olive, shining epidermis; external ligament slight; cartilage as in Leda; pallial sinus deep. Yoldia myalls. Coutli. is a characteristic species. 17. Yoldia cooperi Gahh. Yoldia cooperi Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 189; Pal. Cal., Vol. II, 1869, p. 31, PI. IX, fig. 54. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192. Dall, Trans. Wagner Inst. Sci., Vol. Ill, 1898, p. 594. Yoldia inipressa (not of Con., Wilkes Exped., Vol. X, p. 726, PI. XVIII, fig. 13; nor of Meek, Smithsonian Check - List, Mioc); in part, Gabb, Pal. Cal., Vol. II, 1869, p. 59; in part, Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 270. Shell of medium size, oblong, pointed at one end, subcompressed, thin; surface ornamented by numerous small, concentric ribs, abrupt on the upper side, and sloping downward on the side towards the base; beaks minute, placed in advance of middle; anterior end narrow, subacuminate- concave above; posterior end broadly rounded; lunule long, narrow, deeply impressed, smooth; hinge with prominent cup-shaped cartilage-pit, with about twelve sharp teeth in front, and about fifty behind; pallial sinus large, deep and rounded. Dimensions. — Long. 64 mm.: alt. 32 mm.; diam. 10.5 mm.; umbo to anterior end 22 mm., to posterior end 44 mm. The largest of the Nuculidfe found in these deposits; easily distinguishable by its size, peculiar shape, and teeth. One imperfect specimen measured S3 mm. in length. The Miocene form (Y. impressaj is much smaller and less compressed. Specimens identified by Dr. Dall. Rare in upper San Pedro series of San Pedro; three specimens. Found also in Pleistocene of Spanish Bight, San Diego, and Barlow's ranch, Ventura. Living. — Santa Cruz to San Diego (Cooper): Half Moon Bay (Arnold). Pleistocene. — San Pedro (Cooper; Arnold): San Diego; Ventura (Arnold). f?J Pliocene. — San Fernando (Cooper). 18. Yoldia scissurata Dall. Plate XVII, Fig. 13. Yo/dia scissurata Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 595. Yoldia arctica Brod. & Sby., Zool. Jour., 1829 (not of Gray, Parry's Voyage App., 1824, fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, 1898, p. 595). Shell rather small, oval, compressed, very thin, translucent, only slightly narrowed posteriorly; umbones minute, slightly anterior to middle, the anterior margin is evenly convex; a thin lamina runs along the anterior margin from the umbo to the end of the shell; a much narrower one also 100 CALIFORNIA ACADEMY OF SCIENCES. occurs on the posterior margin; surface sculptured concentrically as in }'. cooperi except that this incised sculpture is not in harmony with the incremental lines; hinge and teeth similar to Y. cooperi. Dime7isio7is.- — Long. 20.4 mm.; alt. 10 mm.; diam. 4 mm. ; from umbo to anteriorend 9 mm. ; to posterior end 12 mm. This delicate little shell resembles Y. cooptri \\\ many respects, but is easily distinguishable by its smaller size, more delicate shell, the peculiar way in which the sculpture crosses the incremental lines, and by its relatively broader anterior end. Probably the Y. amygdala Yal. reported by Cooper (7tli Ann. Rept. Cal. St. Min., 1888, p. 270) as occurring at Deadman Island is Y. scissurata Dall. Specimens identified by Dr. Dall. Three specimens from lower San Pedro series of Deadman Island; lare. Specimens of Y. scissurata in the State Museum collection of fossils at Berkeley are labeled Y. amygdnla. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Puget Sound (Carpenter). Pleistocene. — San Pedro (Arnold. Superfamily ARCACEA. Family VII. ARCID.E. Subfamily PECTUNCULlNyE. Genus Glycy maris Da Costa. Shell orbicular, nearly equilateral, smooth or radiately striated; umbones central, divided by a striated ligamental area; hinge with a semicircular row of transverse teeth; adductors subequal; pallial line simple; margins crenated inside. Type, Area glycymeris Linn. 19. Glycymeris barbarensis Conrad. Plate XVIII, Fic. 9. Axi7tea barbarensis Con., Pac. R. R. Rept., Vol. VI, 1857, p. 71, PI. Ill, fig. 11; Vol. VII, 1S57, p. 194, PI. VI, fig. 3. Axinea intermedia (not of Brod. ; not of Carpenter, Brit. Assn. Rept., i86j, p. 644), of Cooper, in part, 7th Ann. Rept. Cal. St. Min., 1888, p. 230 (not of Keep, West Coast Shells, 1892, p. 169; not of Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192; not of Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 608. Shell of medium size, convex, thick, subcircular, with angular aspect at umbones caused by the anterior dorsal margin being nearly straight; posterior end rounded; anterior end angular; sur- face area between umbones and interior as in G. septentrionalis. Dimensions. — Long. 33.3 mm.; alt. 32 mm.; diam. 22 mm. Distinguishable from 0. septentrionaliii. by wider, more trigonal shell and angular AENOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 101 aspect of anterior extremity. Thi.s fossil form of Conrad's is separated from the living O. intermedia by Dr. Dall. Specimens identified by Dr. Dall. Rare in upper San Pedro series of San Pedro, Los Cerritos, Deadman Island and Crawfish George's. Found also in the Pleistocene of Pacific Beach, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Pleistocene. — Santa Barbara (Conrad): San Pedro (Arnold): San Diego (Arnold). 20. Glycymeris septentrionalis MUUemhrf. Plate XVIII, Fm. 10. Pechinculus septenbionalis Midd., Carpenter, Brit. Assn. Rept., 1856, p. 219. Shell of medium size, nearly circular, conve.x, thick; umbones central, not prominent; sur- face sculptured with rather faint ridges of growth and radiating grooves, which are more or less interrupted by the ridges; triangular ligamental area between umbones divaricately striated; hinge with a semicircular row of transverse teeth; muscle impressions subequal; interior of margin crenulated. Dimensions. — Long. 30 mm.; alt. 32.2 mm.; diam. 22 mm. Distinguishable from O. harharens.h by its evenly rounded outline. Differs from Carpenter's living P. septentrionalis var. subobsoleta by having larger, thicker shell, greater convexity, and more pronounced sculpture. Specimens identified by Dr. Dall. Rare in upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's, Deadman Island and Long Beach. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Ukamok Island, Alaska coast (Carpenter). Pleistocene. — San Pedro (Arnold). Subfamily ARGIN^E. Genus Area (Linne) Lamarck. Shell oblong, subquadrangular, gaping anteriorly or inferiorly; hinge linear, straight, formed of a large number of small pectinated teeth; ligament external, inserted upon a lozenge-shaped area between the beaks, beaks high, rather wide apart; muscular impressions very distinct; pallial im- pression entire. Type, Area nom Linne. 21. Area labiata Son-erhij. Plate SVIII, Fig. 4. Area labiata Sby., Carpenter, Brit. Assn. Rept., 1856, pp. 310, 363. Shell of medium size and thickness, arculate below, straight above, with small but promi- nent presocoelous beaks; anterior extremity evenly rounded; posterior extremity angular near base, a rather prominent convex angle running from beak to lower portion of the posterior extremity; right 102 CALIFORNIA ACADEMY OF SCIENCES. valve with twenty-eight square topped, rather narrow, radial ridges, separated by shghtly narrower interspaces; cardinal area triangular, broad, faintly sculptured with parallel lines transverse to hinge line; two nearly equal series of teeth, crowded in middle, becoming slightly oblique and further separated at the distal ends; margins serrate. Dimensions. — Long. 28 mm.; alt. 26 mm.; distance between dorsal and ventral margins 20 mm.; umbo to anterior extremity 11 mm.; to posterior e.xtremity 17 mm. 'ibis is the only Area so far reported from the Pleistocene of the Pacific Coast. It has been reported by Carpenter as being one of the few species common to both the West Indian and Pacific (Panama) faunas. This species and Hippomjx antiqua- tus, which Carpenter considers equal to H. miirula of the West Indian fauna, are the only two species which occur in the Pleistocene of San Pedro and the living fauna of the West Indies. These two species offer no proof of a close water connection be- tween these two regions during Pleistocene time, for the occurrence in both regions of these two species is merely accidental, or a coincidence. The specimen described was identified by Dr. Dall. Rare in the upper San Pedro series of San Petlro; two specimens, a right and a left valve. The specimen figured is from the upper San Pedro serie.< at San Pedro, and is now in the collection of Delos Arnold. Lioing. — Gulf of California; Central America; West Indies (Carpenter). Pleistocene. — San Pedro (Arnold). Superfamily OSTRACEA. Family VIII. OSTREID.E. Genus Ostrea (Linnf) Lamarck. Shell irregular, attached by the left valve; upper valve flat or concave, often plain; lower convex, often plaited or foliaceous, and with a prominent beak; ligamental cavity triangular or elongated; hinge toothless, structure subnacreous, laminated, with a prismatic-cellular substance between the margins of the laminte. Type, Ostrea edulis Linne. 22. Ostrea lurida Carpenter. Ostrea lurida Cpr., Brit. Assn. Rept., 1S63, p. 645; Jour, de Conch., Vol. XII, 1865, p. 137. Gabb, Pal. Cal., Vol. II, i86g, p. 106. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 256. Keep, West Coast Shells, p. 164, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 193. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 687. Shell of medium size, irregular, suborbicular, ellipsoidal, or elongated; surface laminated and sometimes irregularly plaited; beak prominent; hinge toothless. Di9netisions. — Long. 35 mm.; alt. 50 mm. Grades into two varieties, expansa Cpr., which is nearly circular, and rafoides Cpr., which is of a retldish hue on the interior. Specimen identified by Dr. Dall. AKNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 103 Typical form exceedingly common in the upper San Pedro series of San Pedro, Los Cerritos and Long Beach; rare in the lower San Pedro series of Dead man Island and San Pedro. Fonnd also in Pleistocene of Twenty-sixth street and Pacific Beach, San Diego. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — Benicia, Solano County; San Diego (Cooper; Arnold): San Pedro (Arnold). Superfamily PECTINACEA. Family IX. PECTINID.E. Genus Pecten Midler. Shell suborbicular, regular, resting on the right valve, usually ornamented with radiating ribs; beaks approximate, eared; anterior ears most prominent; posterior side a little oblique; right valve most convex, with a notch below the front ear; hinge margins straight, united by a narrow ligament; cartilage internal, in a central pit; adductor impression double, obscure; pedal impression only in the left valve, or obsolete. Type, Ostrea maximd Linne. Subgenus Pecten .s. s. Right valve moderately inflated, left valve flattish; sculpture of strong ribs with radial stri- ation, more or less roughened by simple concentric lamellation or incremental sculpture; ears subequal. Type, Pecten mn.ciinus Linne. [S. B.] Pecten (Pecten) bellus Conrad. Plate XXI, Fics. 1 and 2. Janira bella Conrad, Proc. Acad. Nat. Sci. Phila., 1S56, p. 312; Pac. R. R. Rept., Vol. VI, 1857, p. 71, PI. Ill, fig. 16. Gabb, Pal. Cal., Vol. II, 1S69, PI. XVI, fig. 20. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 244; not P. bellis McCoy {teste Dall). Pecten (Pecten) hemphitli Dai.1., Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p, 706 (pars. ?). Pecten (Pecten) bet/us Con., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 704. Shell large, thin, inequivalve, elegantly, radiately ribbed. Left (upper) valve slightly convex, the point of greatest convexity being generally about one-fourth the distance from the apex toward the ventral margin; between this point of greatest convexity and the apex there is a deeply depressed area, the depression generally not affecting the two outer ribs on each side, which inclose the depres- sion on the sides; surface of left valve ornamented by thirteen or fourteen prominent, flat-topped, sometimes faintly bicarinated, radiating ribs, which have flat, sloping sides; these ribs become broader, less elevated and less sharply angulated near the periphery in the adult; interspaces slightly wider than the tops of the ribs, with slightly rounded bottoms; whole surface of left disk covered with fine, sharp, concentric, regular lamelkt; ears rather small, subequal, slightly concave, finely concentrically lamellated, separated from the disk by an impressed line. Right (lower) valve prominently convex, the point of greatest convexity being about one-third the distance from the apex to the ventral margin of the disk; the umbo in this valve curves sharply and meets the plane of the ears at an angle of 104 CALIFOKNIA ACADEMY OF SCIENCES. about ninety degrees; surface of right valve ornamented by fourteen or fifteen prominent, nearly flat- topped, square, radiating ribs, some of them with one or two longitudinal obsolete lines; the ribs become somewhat less elevated and the sides more sloping as the periphery is approached in the adult; surface of right disk ornamented with close, fine, squamosa, concentric wrinkles; ears subequal, arched, covered with crowded, elevated lamelke; byssal notch small. Dimensions. — Alt. 80 mm.; lat. 108 mm.; diam. 32 mm.; length of hinge-line, 45 mm. Found in the Pliocene at tSanta Barbara, California (Coniad, Gabb, Yates Cooper, Arnold). The description, measurements, and figures are of Gabb's type specimen of Janira bella (No. 960, Collection Academy Natural Sciences, Philadelphia), which was kindly loaned to the writer by Professor H. A. Pilsbry, Curator of Mollusca. F. stearnsii and P. diegeiisis are distinguishable from P. bellus by the more numerous (25 or 28 in the first, 20 or 22 in the second), narrower, sharper defined, perpendicular-sided, radiating ribs on the right valve, and by evenly rounded, promi- nently and evenly lamellated ribs of the left valve. /'. hemphilli is distinguishable from P. hellua by its smaller size; by having on the right valve more numerous (15 or 16 in the former), round-topped, narrower, nearly perpendicular-sided, radiating ribs, which retain their prominence for their entire length, and by the less convexity of the disk, more numerous, narrower and more elevated radiating ribs of the left valve. P. hemphilli has the .same depression below the apex in the left valve, but the less degree of convexity of the rest of the disk lessens the prominence of the de- pression, which is so marked in most specimens of P. bellns. P. deutains is dis- tinguishable from P. bellns by its smaller size, greater convexity of right valve, greater concavity of left valve, greater number of ribs, and by the auxiliary ribs in the left valve. After a careful comparison of a large series of P. bellus with Conrad's descrip- tion and figure and Gabb's figure and type specimen, the writer has no hesitancy in adopting the synonymy given at the beginning of this article. Dall is of the opinion that Conrad's species and that of Gabb are different. This idea was probably caused by the exaggeration of the bicarination of the ribs in Conrad's figure. Several of the specimens of P. bellus examined by the writer show this bicarination to a greater or less degree, although as a rule the ribs are nearly smooth-topped. A large series of /■'. bellus and P. hemi^hilli show the differences enumerated in a previous paragraph to be constant for the adults. The young of both species up to an altitude of twenty millimeters are nearly identical in appearance. 23. Pecten (Pecten) dentatus Soirerbi/. Plate XII, Figs. 1 and In. Pecten dentatus Sbv., Thes. Conch., Vol. I, p. 39, PI. XV, figs. 105, 106. Dall, Trans. Wagner Ins. Sci., Vol. Ill, Part 4, 1892, p. 707. Vola dentata Sby., H. &. A. Ad.vms, Gen. Rec. Moll. /anira dentata Sby. {=J. excavata, Val., 7?af^ Carpenter, Brit. Assn. Rept., 1863, p. 654). Gabb, Pal. Cal., Vol. II, 1869, p. 104. Cooper, -th Ann. Rept. Cal. St. Min., 1S88, p. 244 (==/'. stearnsii Dall, in part). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 105 Shell of medium size, subcircular, inequivalve, concavo-convex, rather thin; right valve gib- bous, with twenty smooth, rounded, only moderately convex ribs, separated by very faintly channeled, narrow interspaces; surface smooth except for fine, undulating lines of growth; ears on this valve con- vexly bent, and separated from the disk by a deep groove; anterior ear with small byssal notch, obsoletely, radiately ribbed, and with fine incremental lines; posterior ear similar except that it lacks the notch; left valve concave, with nineteen or twenty prominent squarish ribs, which are separated by deep channeled interspaces of equal width with the ribs; a faint rounded rib runs along the middle of each of the interspaces; surface with fine undulating incremental lines; ears of this valve concave, with obsolete radiating ridges and fine lines of growth. Dimensions. — Long. 70 mm.; alt. 67 mm.; diam. 25 mm.; hinge 35 mm. Distiugaishable from P. liemphilli Dall by greater convexity of the right valve, and by the greater number of ribs, P. hempldUi having only about fifteen ribs; distinguishable from P. stearnsii and P. dlegensis Dall by greater convexity of right valve, low rounded ribs rather than square ones on this valve; and by square ribs, between which are faint rounded riblets, rather than sharply rounded ribs on the left valve. P. dentatus is of the same shape as the Japanese species P. laqueatus Sby., which has fewer, but squarer, broader ribs on the right valve. This last species has been reported from the Tertiary of Japan by Dr. Brauns in his Geology of the Environs of Tokio.' "P. laqueatus has been erroneously cited by Reeve from Cali- fornia" (Dall). An almost perfect right valve of this beautiful southern shell was found in the upper San Pedro series of San Pedro. It differs from a living specimen from the Gulf of California by having twenty rather than twenty-three ribs, and by having slightly less convex ribs and wider interspaces. In degree of convexity and in its ears it agrees exactly with the living shell. The specimen was identified by Dr. Dall. Cooper has mistaken the flat valve of P. dearnsii for this species. A specimen in the State Museum collection at the University of California, Berkeley, labeled "Janira dentata Sby., San Pedro, Quaternary," is a P. stearnsii from the Pliocene of Deadman Island. The specimen figured is a living shell from the Gulf of California, and is now in the collection of the Department of Geology, Leland Stanford Junior University. Living. — Gulf of California (Carpenter; Button). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold). Pliocene. — San Diego well (Cooper) — (probably P. hemphilli). [S. D.] Pecten (Pecten) hemphilli Dall. Peden hetnphilli Dall. , Proc. U. S. Nat. Mus., Vol. I, 1879, p. 15. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 706. Not Janira bella CoN., Pac. R. R. Rept., Vol. VI, 1857, p. 71, PI. Ill, fig. 16; nor Gabb, Pal. Cal., Vol. II, 1869, PI. XVI, fig. 20. Shell of medium size, thin, inequivalve. Upper (left) valve flat or slightly concave, with a concave depression between middle of valve and umbo; surface of this valve sculptured by sixteen > Mem. Univ. Tokio, No. 4, 1881, p. 48, PI. VII, fig. 31. ( 14 I November 3, 1902. 106 CALIFORNIA ACADEMY OF SCIENCES. or seventeen very prominent, rather narrow radiating ribs, which are nearly fiat-topped and have nearly perpendicular sides; interspaces wider than ribs, with rounding bottoms; fine incremental lamellae cover the surface of this valve; ears square-cornered and concave, covered with incremental lamelke. Lower (right) valve convex, most apparent between middle of valve and umbo; sculptured by sixteen prominent squarish ribs, which are similar to those on the upper valve, except that they are slightly broader and have a more rounded top; whole surface sculptured by very fine incremental lines; ears similar to those of upper valve except convex, and the right one having three or four radi- ating ridges and a small byssal notch. Dimerisions. — Long. 63 mm.; alt. 56 mm.; diam. 15 mm.; hinge-line 28 mm. This species is readily distinguishable from P. stearnsii and P. diegensis by its smaller size, greater convexity of lower valve, and fewer ribs. Distinguishable from P. bellus by smaller size, flat or concave upper valve, and narrow, more elevated and prominent radiating ribs. Common in the upj^er horizon of the Pliocene at Pacific Beach, and also in the strata exposed on Tenth Street, near Russ School, San Diego. Pliocene. — Pacific Beach and Buss School, San Diego (Hemphill; Dall; Arnold). 24. Pecten (Pecten) stearnsii Dull. Plate XII, Fin. 3. Pedoi stearyisii Dall., Proc. U. S. Nat. Mus., Vol. I, 1878, p. 14; Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 706, PI. XXVI, fig. 5. /antra dentata Sby. (?), Gabb, Pal. Cal., Vol. II, 1S69, p. 104 (in part). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 244 (in part). Shell of medium size, subcircular, inequivalve, concavo-convex, thin; right valve slightly convex, with about twenty-six regular, even, square ribs, separated by channeled interspaces some- what narrower than the ribs ; the top surface of each rib is flattened with a broad, shallow groove in the middle, with one or two faint riblets on each side of the groove; whole surface covered with concentric lamelte which are much finer and about twice as crowded as those of the left valve; left valve flattened or concave, with about twenty-four regularly rounded, vaulted, even ribs, separated by slightly wider channeled interspaces; the whole surface covered with fine, sharp, concentric, regular lamellae, a little looped backward over the tops of the ridge; ears of this valve concave, with obsolete radiating ridges, and fine, concentric lamellae; ears of right valve subequal, arched, covered with crowded, elevated lamellae; byssal notch very small. Dimensions. — Long. 71 mm.; alt. 62 mm.; diam. 14 mm ; hinge 25 mm. "This is the Pliocene precursor of P. diegensis Dall (Plate XII, fig. 5), {P. floridus of Hinds, not of Gmelin) from which it differs by having five or six more ribs, which, in the adult, have a conspicuous median sulcus." (Dall.) Mrs. Old- royd has eight P. diegensis which have been hauled up in the fishermen's nets at San Pedro; two of these are over six inches in diameter and are exceptionally high colored for this species. Two imperfect left valves from the Pliocene of Deadman Island. The figure is of a left valve from the Pliocene of San Diego. Specimens identified by Dr. Dall. Pliocene. — San Pedro (Arnold) : San Diego (Pacific Beach, lower horizon), (Dall; Hamlin; Hemphill; Arnold). AENOLD— THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDKO. 107 Subgenus Chlamys Bolten. Valves moderately inflated, subequal, in general similar (except in color); sculpture of radial ribbing with or without Camptoyiectes striation, with or without an imbricate surface layer; frequently spinose on the ridges; ears often discrepant, the posterior smaller. Type, Pecten islandicus (Miiller). Section Patinopeden Dall. Valves with small ribs, flat on the right valve and sometimes dichotomous; smaller and more rounded on the left valve; concentric sculpture inconspicuous; radial stride absent or obsolete; ears subequal ; valves nearly equilateral. T3'pe, Pecten cauiinus (Gld.). 25. Pecten (Patinopecten) caurinus Gould. Plate XIII, Fig. 6. Peclen caurinus Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1850, p. 345; Wilkes E.xpl. Exped., Vol. XII, 1852, p. 458, fig. 569. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 193; T=: p. yessoeiisis Cpr., (non Jay, 1856); ^= P. propatulus Carpenter (non Conrad, 1849) {Jide Dall., Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 710). Amusium cauriuum Gld., Carpenter, Brit. Assn. Rept. , 1863, p. 645. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 228. Keep, West Coast Shells, p. 168, 1892. Shell large, nearly circular, flat inequivalve, rather thin; right valve with twenty strong, flat-topped, smooth, squarish ribs, with interspaces wider than the ribs ; left valve less conve.x than right, with seventeen rather acutely rounded ribs, with wide, shallow interspaces ; surface of left valve sculptured by regular, fine, undulating, concentric lines; ears not large, obliquely truncated at ends. Dimensions. — Long, no mm.; alt. no mm. ; diam. 16 mm.; hinge 46 mm. Tliis large, flat Pecten i.s distinguishable from the others of this genus found in these deposits b}^ its size and shape. P. expansua Dall differs from this species by having twenty-five to thirty dichotomous ribs. P. yessoensis from Amori, Rikonoken, Japan, differs from P. caurinus by having a more convex shell, wider, lower, more rounded ribs on the right valve, less prominent ribs on the left valve, and by hav- ing larger ears, which are truncated more nearly at right angles at the ends. Pecten jtrojMtulus Conrad is more convex and has fewer but stronger ribs and narrower interspaces on the right valve. Specimens identified by Dr. Dall. Common in the Pliocene of Deadman Island and Timm's Point; rarer in the lower San Pedro series of Deadman Island and San Pedro. Also found in Pleisto- cene on beach near bath-house and in Pliocene at Packard's Hill, Santa Barbara. The specimen figured is from the Pliocene of Deadman Island and is now in the col- lection of Delos Arnold. Living. — Puget Sound (Carpenter). Pleistocene. — Santa Barbara; San Pedro (Cooper; Arnold). Pliocene. — Eagle Prairie, Humboldt County; San Fernando (Cooper). 108 CALIFORNIA ACADEMY OF SCIENCES. [S. D.] Pecten (Patinopecten) expansus Dali. Pecieti expansus Dall, Proc. U. S. Nat. Mus., Vol. I, 1879, p. 14; Trans. Wagner Inst. Sci., Vol- III, Part 4, 1898, p. 706. Shell large, thin, slightly convex ; outer surface of upper (left) valve marked by sixteen to twenty sharp radiating ridges, but slightly elevated, and whose sides shade off insensibly into the broad interspaces ; faint indications of ridges appear between the principal ones ; surface of upper valve covered with fine, slightly raised, sharp lamellae ; lower (right) valve with twenty or thirty dichotomous ribs, flattened above, but not sharply differentiated from the interspaces, sculptured with fine lines of growth, with faint appearances of radiating strite ; ears rather small, and distinctly but not strongly marked off" from the disk ; byssal notch rounded, moderately deep. Dimensions. — Long. 140 mm.; alt. 135 mm.; diam. 32 mm.; hinge-line 65 mm. This species is close to P. cnurinus, but may be distinguished by the dicho- tomous ribs on the lower valve, and the faint ribs between the principal ones on the upper. A species of Pecten near, if not identical, to P. expansus is found in the Plio- cene near Purisiraa, Sau Mateo County, California. P. expansus is common in the lower horizon of the Pliocene at Pacific Beach, near San Diego. Pliocene. — Pacific Beach, San Diego (Hemphill; Dall; Hamlin; Arnold). Section Nodipecten Dall. Both valves convex, usually of large size and heavy ; ribs intermittently nodose, with more or less prominent hollow nodes or buttse ; radial striation pronounced ; ears unequal, the pos- terior smaller; the valves often more or less oblique; imbricate surface layer sometimes very marked. Type, Pecten nodosus Linne. 26. Pecten (Nodipecten) subnodosus Soiverby. Pecten suktiodosus Sby., Proc. Zool. Soc, 1835, p. 109. Carpenter, Brit. Assn. Rept., 1856, p. 311; Brit. Assn. Rept., 1S63, p. 621. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 710. Pec/en ijitermedius Con., Am. Jour, Conch., Vol. Ill, 1867, p. 7. Shell large, suboval, convex; surface sculptured with numerous high, square ribs, three or four of which are generally more prominent than the others; interspaces deeply channeled, averaging about equal in width with the ribs; surface, including the ribs and interspaces, sculptured by fine radiating, squamose ridges, and fine lines of growth; ears rather small, sculptured in same manner as the disk. Dime7isio7is. — Long. 120 mm.; alt. 125 mm.; diam. 45 mm. This large tropical species is distinguishable by strong elevated ribs and pecu- liar squamose, radiating ridges. Dr. Dall .says of this species: "There seems to be little reason for separating this form from the P. nodosus of the Antilles. Both vary through a strictly analogous series of mutations." One-half of a large left valve was found in the upper San Pedro conglomerate of Deadman Island by Dr. A. A. Wright, who also found a young specimen of the same species in the upper San Pedro series of San Pedro. Living. — Lower California to Panama (Carpenter). Pleistocene. — San Pedro; San Diego (Arnold): Cerros Island and Lower Cali- fornia (Dall). ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 109 Section Chlaviys s. s. Ribs small and numerous, imbricate or spinose; valves subequal, similar, oblique, or with unequal ears, the posterior smaller; Ca^nptonedes striation and imbricate surface layer usually present; shell usually solid and opaque; byssal notch and ctenolium present. Type, Peden idandicus (Mllller). 27. Pecten (Chlamys) hastatus Soiverby. Plate XI, Figs. 4 and 4«. Pedeii hastatus Sby., Thes. Conch., 1843, p. 72, PL XXII, fig. 236 (not of Carpenter, Brit. Assn. Rept., 1863, p. 645 = /". hericeus Gld.); (? not of Gabb, Pal. Cal., Vol. 11, 1869, p. 104); (? not of Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257). Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 708. Shell similar in shape and general characteristics to P. hericeus. Left valve sculptured with eight to ten prominent, narrow, convex, coarsely spinose, radiating ribs separated by interspaces several times wider than the ribs; interspaces ornamented with fasciculi of small spinose ribs, which in some cases have only the importance of spinose lines; anterior ear large, acutely pointed, with three or four prominent, spinose, radiating ribs; right valve with eight to ten pairs of equally prominent, coarsely spinose ribs, each pair separated from the next by deep rounded interspaces along the bottoms of which run fine spinose lines: the members of each pair of ribs separated from each other by interspaces about as wide as one rib, and also ornamented with spinose lines ; anterior ear with four or five strong spinose ribs and separated from disk by deep notch; posterior ears nearly obsolete, radiately spinose. Dimensions. — Long. 54mm.; alt. 61 mm.; diam. 21 mm.; hinge 28 mm. Distinguisliable from P. hericeun by the less nuraerou.s, but more prominent and more strongly spinose radiating ribs. Dr. DalP says that Carpenter confused P. hericeus with P. hastatus, and as Gabb and Cooper have probably used Car[)enter's P. " hastatus " as their type, their localities for that species would come under P. hericeus. Mrs. Oldroyd has a beautiful pair of Pecten hastatus which was taken from a fisherman's net at Ban Pedro. Dr. Dall identified this shell and said that it was the first genuine P. hastatus that had ever been found at San Pedro. This species is a northern form. Rare in Pliocene and lower San Pedro series of Deadman Island; one speci- men from upper San Pedro series of Crawfish George's. The specimen figured is from the Pliocene of Deadman Island, and is now in the collection of Delos Arnold. Found also in the Pliocene at Packard's Hill, Santa Barbara, and Pacific Beach, San Diego; and in the Pleistocene at the bath-house, Santa Barbara. Living. — San Pedro (Oldroyd; Raymond). Pleistocene. — San Pedro; Santa Barbara (Arnold). Pliocene. — San Pedro; Santa Barbara; San Diego (Arnold). 1 Trans. Wagner Inst. Sci., Vol. Ill, 1898, p. 708. 1 1 0 CALIFORNIA ACADEMY OF SCIENCES. 28. Pecten (Chlamys) hericeus Gould. Plate XI, Fig. 2. Pecten hericeus Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1S50, p. 345; Wilkes E.xpl. E.>;ped., Vol. XII, 1852, p. 457, fig. 570. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 708. Pecten hastatus of Carpenter, Brit. Assn. Rept., 1863, p. 645 (not of Sowerby, Thes. Conch., 1843). ? Gabb, Pal. Cal., Vol. II, 1869, p. 104. ? Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257. Shell of medium size, triangular ovate, compressed, equivalve, thin; surface of left valve sculptured by about fourteen to sixteen groups of fasciculated ribs, the groups being more prominent and containing more ribs as the middle of the shell is approached; the surface of all the ribs roughened by numerous rather small, erect, arched spines; right valve nearly the same as left; anterior ear of left valve large, acutely pointed with seven to eight sharp, squamosely striated radiating ribs; posterior ear nearly obsolete; ears of right valve the same e.xcept that a deep byssal notch separates anterior ear from disk; sides of umbo rise abruptly from ears. Dime^isions. — Long. 40 mm.; alt. 47 mm.; diam. 12 mm.; hinge 19 mm. Thi.s species resembles P. hastatus in shape and general characteristics. In P. hastatus there are seven to ten strong, narrow, prominent ribs, coarsely spinose, while in P. hericeus the ribs occur in fourteen to sixteen fasciculi, each fascicle con- sisting of three or four nearly equally prominent, finely spinose ribs, and forming a convex ridge. Specimens identified by Dr. Dall. Rare in Pliocene of Deadman Island. The specimen figured is fi-om that horizon and is now in the collection of Delos Arnold. Found rarely in the Pliocene of Pacific Beach, San Diego. JAving. — Straits of Fuca (Gould) : ? Sitka to Santa Barbara (Cooper). Pleistocene. — San Diego (Dall) : ? Santa Barbara to San Diego (Cooper) : San Pedro (Arnold). Pliocene. — San Pedro (Arnold): ? Santa Barbara; San Fernando; San Diego well (Cooper): San Diego (Arnold). 29. Pecten (Chlamys) hericeus var. strategus Dall. Pl.-vte XI, Fig. 5. Pecten hericeus var. strategus Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 709. Shape and general te.xture same as P. hericeus. " The fasciculi of the left valve, to the number of five to seven, with the riblets coalescent, forming large, smooth-backed, turgid ribs, with smaller imbricate intercalary threads. The large ribs sometimes break up suddenly into the usual small riblets near the base. The recent specimens are bright scarlet." (Dall). The right valve oi a young from the Pleistocene of Deadman Island shows nine fasciculi, most of which seem to be made up of two riblets which keep their individuality to the umbo, instead of coalescing; the interspaces are slightly narrower than the fasciculi. The anterior ear of this right valve is prominent and ornamented with six radiating ribs, and near the disk, by elevated lines of growth; byssal notch rather deep; whole surface ornamented with minute, lattice-like scul[)ture. Dimensions. — ^Long. 18 mm.; alt. 21 mm.; diam. 5.2 mm.; hinge 9.4 mm. AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. HI Distinguishable by the few prominent, sulcated ridges, and smooth surface, except for minute sculpture. Specimens identified by Dr. Dall. Two specimens from the lower 8an Pedro series of Deadman Island, one of which is figured, and is now in the collection of Delos Arnold. Living. — Unalaska (Dall). Pfeis^ocene.^Alaska (Dall): San Pedro (Arnold). 30. Pecten (Chlamys) jordani, sp. nov. Plate XII, Figs. 6 axd 7. Shell of medium size, shape of/', hericeus, inequi valve, rather thin; right valve with twenty- five to thirty angular, smooth-topped, imbricated ribs, which become dichotomous after reaching a length of about 30 mm.; interspaces deeply channeled and narrower than ribs; anterior ear imper- fectly radially ribbed with six ridges, and showing elevated, concentric, incremental lines; posterior ear nearly obsolete, showing four ribs; byssal notch not deep; left valve shows twenty-five to thirty narrow, convex ribs, showing imbrications only slightly; interspaces as large as ribs; after a diameter of about 30 mm. has been reached by the shell, small riblets appear in the widening interspaces; anterior ear shows five narrow, imbricated ridges, with wide interspaces; both valves show a tendency to contract suddenly at the basal margin upon nearing completion of growth ; surface of both valves covered with a minute, lattice-like sculpture, which is generally worn off on exposed portions of the shell. Dimensions. — Long. 42 mm.; alt. 45 mm.; diam. 15 mm.; hinge 18 mm. Allied to F. opimtia Dall, but having fewer ribs on disk and ear, and having dichotomous ribs after reaching a diameter of 35 mm. Distinguished from P. hericens and P. hastaius by not having fasciculated nor spinose ribs. Rare in Pliocene of Deadman Island and lower San Pedro series of Deadman Island. Found also in Pliocene of Packard's Hill and Pleistocene of bath-house, Santa Barbara. The specimen figured is the type, which is from the Pliocene of Deadman Island and is now in the United States National Museum. Pleistocene. — San Pedro, Santa Barbara (Arnold). Pliocene. — San Pedro, Santa Barbara (Arnold). 31. Pecten (Chlamys) latiauritus Conrad. Plate XII, Figs. 2 and 2a. Pecten latiauritus Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 238, PI. XVIII, fig. 9. Reeve, Conch. Icon., PI. I, sp. 5. Sowerby, Thes. Conch., PI. I, p. 57. Carpenter, Brit. Assn. Rept, 1863, p. 645. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257. Keep, West Coast Shells, p. 167, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 193; = P. tioiica Phil., 1844, -\- P. mesotimeris Sowerby, 1847 {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 709.) Shell small, suboval, inequivalve, subequilateral, compressed, thin ; surface ornamented with from twelve to fifteen squarish, elevated, distinct ribs, with about equal, channeled interspaces; ribs often mesially grooved; hinge line wide, the ears pointed above. Dimensio7is. — Long. 25 mm.; alt. 23 mm.; diam. 9 mm.; hinge 20 mm. 112 CALIFORNIA ACADEMY OF SCIENCES. This is the type form and is distinguishable by acutely pointed ears, distinct, squarish ribs and wide shell. Specimens identified by Dr. Dall. Common in upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's, Deadman Island, San Pedro, and Long Beach; rare in lower San Pedro series of Deadman Island and San Pedro. Found also at Spanish Bight and Twenty- sixth Street, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Santa Barbara to San Diego (Carpenter). Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold): San Pedro; San Diego (Dall): San Diego (Arnold). 32. Pecten (Chlamys) latiauritus Con., var. fragilis, var. nov. Plate XII, Fig. 8. Shell of same general type as P. latiauritus. More compressed and much thinner; ribs seven to nine, very low and rounded, with shallow, rounded interspaces; surface smooth, the concentric sculpture being nearly obsolete ; hinge long, ears sharply pointed. Dimensions. — Long. 26 mm.; alt. 26 mm.; diam. 78 mm.; hinge 25 mm. Distinguishable from var. jlucicolus Dall, which it resembles, by having a longer hinge-line and pointed ears. Rare in upper San Pedro series of San Pedro and Los Cerritos. The speci- men figured is the type, which is from the upper San Pedro series at San Pedro, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). 33. Pecten (Chlamys) latiauritus Con., var. monotimeris Con. Plate XII, Figs. 4 and -ta. Pecten motiotimeris Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 233, PI. XVIII, fig. 10. Carpenter, Brit. Assn. Rept., 1863, p. 645. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257. Keep, West Coast Shells, p. 167, fig. 140, 1892. Pecten latiauritus vav. 7no)iotimeris Coii. , Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 709. Shell resembling P. latiauritus, but more oblique, inflated, and markedly shorter, with smaller ears. Dimensions. — Long. 19 mm.; alt. 20 mm.; diam. 9 mm. Rare in lower San Pedro series of Deadman Island and San Pedro, and in upper San Pedro series of Los Cerritos, San Pedro, Long Beach, and Crawfish George's. Found also in Pleistocene of Spanish Bight, San Diego, and Barlow's ranch, Ventura. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Santa Barbara to San Diego (Dall). Pleistocene. — Santa Barbara; San Pedro (Dall): San Pedro; San Diego; Ventura (Arnold). AKNOLD— THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 113 I [S. D.] Pecten (Chlamys) opuntia Dull. Pecten (Chlamys) opuntia Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 707, PL XXIX, fig. 6. Shell of medium size, allied to P. hericeus var. navarchus Dall, from which it differs by its smaller and not fasciculated radial ribs, more elongated anterior ear, more densely, radially costate posterior ear, small size when adult, and by a tendency to be suddenly contracted at the basal margin on the completion of growth. Dimetisions.— Long. 32.5 mm.; alt. 35 mm. This species is distinguishable from tlie allied species by the large number (forty or fifty) of unfasciculated imbricated ribs, which are of about equal prominence. Found in the Pliocene at Pacific Beach, near San Diego, and in the Pliocene at Packard's Hill, Santa Barbara. Pliocene. — Santa Barbara (Arnold): San Diego (Hemphill; Hamlin; Arnold). Section Plagioctenium Dull. Shell thin, orbicular, with subequal inflated valves, usually equilateral, with uniform, well- marked radial, not dichotomous ribs; the concentric sculpture in looped lamellae; the ribs strong, frequently smooth above; the submargins impressed below the subequal auricles; the valves well inflated, with a tendency to oblique growth in the adult. Type, Pecten ventricosus Sowerby. 34. Pecten (Plagioctenium) newsomi, sp. nov. Plate XI, Figs. 1 and la. Shell of medium size, ovate-triangular, compressed, equilateral, rather thin; twenty-two stout, smooth-topped, squarish ribs, with channeled interspaces of same width as ribs ; interspaces and sides of ribs showing sharp imbricating lines of growth; ears of left valve subequal, with subacute corners; surface of ears radially striated, and showing sharp incremental lines. Dimeiisions. — Long. 24 mm.; alt. 26 mm.; diam. 8 mm.; hinge 16 mm.; angle of dorsal margins 87 degrees. This variety is distinguishable from P. venlricosu.^ by the much smaller angle (87 degrees) made by the dorsal margins of the disk, that of a typical P. ventricosus being about 110 degrees. P. neivsomi is also very much less ventricose than the latter, and has much narrower ridges, wider interspaces, and a thinner shell; distin- guishable from P. subventricosns by much smaller angle formed by dorsal margins, and by narrower ridges. It resembles P. subventricosns in degree of convexity. This species is named in honor of Dr. John F. Newsom, of Leland Stanford Junior University. Rare in upper San Pedro series of San Pedro and Los Cei-ritos. The speci- men figured is the type, which is from the upper San Pedro series at Los Cerritos, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). ( 15 ) December 26, 1902. 114 CALIFORNIA ACADEMY OF SCIENCES. [S. D.] Pecten (Plagioctenium) subventricosus Ball. Peclen (Plagioctenium) subventricosus Dall, Trans. Wagner Inst. Sci. , Vol. Ill, Part 4, 1898, p. 707, PI. XXIX, fig. 8. "Shell of the type of P. ventricosus Sby., from which it differs by being smaller and less tumid, less expanded laterally, with the ribs rounded, instead of flattened, above, and with narrow interspaces; the tops of the ribs smooth, the sides with a dense fringe of concentriclamellae." (Dall). Dimensions. — Long. 65 mm.; alt. 65 mm.; diam. 24 mm. Several specimeus of tliis sjiecies were found in the Pliocene of Pacific Beach, near San Diego. Pliocene. — Ventura County (Bovver.s): San Diego (Hemphill; Stearns; Arnold). 35. Pecten (Plagioctenium) ventricosus Sowerby. Plate XI, Fics. 3, 3a, 6 and (in. PecteJi ventricosus Sby., Thes. Conch., Pecten, 1843, p. 51, PL XII, figs. 18, 19. Gabb, Pal Cal., Vol. II, 1869, p. 104. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 258. ^ P. ticmidus Sby., 1835 (not of Turt., 1S22, nor of Zeiten, 1830) = P. circularis Sby. {ex parte) = P. inca d'Orb., 1847 ^fi'^^ Dall., Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1S98, p. 710). Shell thin, orbicular, with subequal inflated valves which are subequilateral ; uniformly radiately ribbed; about twenty-two strong, angular, even ribs separated by narrow interspaces; the whole surface covered with fine, sharp, concentric, looped lamellce, which exhibits the oblique growth in adult shells; ears moderately small, nearly equilateral in left valve; byssal notch prominent; surface of ears ornamented with fine concentric lamelke of growth, and sometimes with radiating ridges. Dimensions. — Long. 59 mm.; alt. 50 mm.; diam. 32 mm.; hinge 31 mm.; angle of dorsal margin 1 10 degrees. P. cequisulcaius Carpenter resembles this species very closely, but is thinner and flatter and has narrower ribs. Probably all the Pleistocene forms would come under the head of P. ventr'icosua, but many of them have been labeled P. /.(^qui- sulcatus. Specimens identified by Dr. Dall. Figures 6 and 6«, Plate XI, represent a shell which was found in the upper San Pedro series at San Pedro, and which is probably a variety of P. ventricosus. Very common in the upper San Pedro series of San Pedro, Long Beach, Los Cerritos, Crawfish George's, and Deadman Island. Found also in Pleistocene on Old Mission ditch, north of Ventura, and in the Pleistocene at Tweuty-sixth Street. Sau Diego. The specimen figured is from the upper San Pedro series at Sau Pedro, and is now in the collection of Delos Arnold. Lioing. — Santa Barbara to west tropical America (Dall). Pleistocene. — San Pedro; San Diego; Lower California (Hemi'hill; Stearns; Orcutt; and Cooper): San Pedro; Ventura; Sau Diego (Arnold). ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHY OF SAN PEDRO 115 Subgenus Hinnites Defrance. Shell (up to advanced youth) a typical Ck/aniys. later becoming- sessile and irregular, in which stage the resilial pit is elongated and the cardinal margin develops an obscure area. Type, HinniteH cortezl Defr. 36. Pecten (Hinnites) giganteus Gray. Hinnites giganteus Gray, Ann. Phil., 1826, p. 103. Carpenter, Brit. Assn. Rept. . 1863, p. 675. Gabb, Pal. Gal., Vol. II, 1869, p. 105. Cooper, 7th Ann. Rept. Gal. St. Min., 1888. p. 243. Keep, West Goast Shells, p. 165, fig. 138, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 193. -f H. poulsoni Conr. ^ (?) //. crassus GoN., {Jide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 711) Shell large, oval, irregular, inequivalve, subequilateral; surface sculptured by about seventeen irregular, squamose, rounded, prominent radiating ridges, with two or three minor ones between each pair of the large ones. Dimensions. — Long. 65 mm.; alt. 65 mm.; diam. 25 mm. Adult.s distinguishable from Pecten on account of distortion caused by attach- ment to some object (hiring the later stages of growth. The young, unattached shells of this species much resemble the young of P. hasfalus. but are distinguishable from this species by a less spinose growth on the ribs, and also in having a much heavier shell. Rare in upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's, and Deadman Island; a few specimens from the lower San Pedro series of San Pedro. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold). Pliocene. — Santa Rosa Island; Ventura County; Los Angeles County (Cooper). Family X. LIMlDyE. Genus Lima {Britgiiin-e) Cnvier. Shell equivalve, compressed, obliquely oval; anterior side straight, gaping, posterior rounded, usually close; umbones apart, eared; valves white, smooth, punctate-striate, or radiately ribbed and imbricated ; there is usually a thin, brownish epidermis ; hinge-area triangular, cartilage pit central ; adductor impression lateral, large, double ; pedal scars, two, small. Lima squamosa Lam. is a characteristic species. Subgenus Lima .s. .s. Hinge edentulous; valves gaping, inequilateral. Section Mantellum Adams Submargins not impressed. Type, Liina hiaiis Gmel. IIG CALIFORNIA ACADEMY OF SCIENCES. 37. Lima (Mantellum) dehiscens Conrad. Lima de/itscens Con., ]our. Phil. Acad. Sci., Vol. VII, 1837, p. 247, PL XIX, figf. 7. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 245. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part4, 1898, p. 769. Lima orieiiialis (not of Ad. & RvE.) of Carpenter, Brit. Assn. Rept., 1863, p. 645. Keep, West Coast Shells, p. 168, fig. 142, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 193. Shell equivalve, compressed, obliquely oval, thin, white; anterior side straight; posterior rounded ; umbones eared, posterior ears acutely pointed ; surface smooth, radiately striate with fine grooves; hinge-area long, narrow, triangular; cartilage pit central, prominent; margin finely crenulated. Ditnensions. — Long. 13 mm. ; alt. 18.5 mm. ; diam. 8 mm. Looks like an obliquely deformed Pecten. Specimen identified by Dr. Dall. Rare in lower San Pedro series of Deadman Island; one specimen collected by Mi-s. Oldroyd. Living. — Monterey to San Diego (Cooper): Santa Catalina Island (Arnold). Pleido'cene. — San Pedro (Mrs. Oldroyd). Pliocene. — Santa Barbara (Cooper). Superfamily ANOMIACEA. Family XL ANOMIID.E. Genus Pododesmus Philippi. Shell suborbicular, very variable, translucent and slightly pearly within ; attached by a plug passing through a hole or notch in the right valve ; a single conspicuous byssal scar on the disk ; valves radiately grooved ; hinge unarmed. Pododesmus rudis Brod. is a characteristic species. Section Monia Gray. Adult hole or foramen large. Pododesmus macliroscTiisma Deshayes is a characteristic species. 38. Pododesmus (Monia) macroschisma Deshayes. Anomia macrosc/iisma Desh., Reeve, Zool. Soc. Cuvierienne, 1S39, p. 359. Mag. Zool., 1841, PI. XXXIV. MiDDENDORF, Beitr. Mai. Ross,, Bd. Ill, 1849, p. 6. Philippi, Abbild. beschr. Conch., 1850, p. 132, PL I, fig. 4. Placunanomia viacroschisma Desh., Gray, Proc. Zool. Soc, 1849, p. 121. Cat. Anam. Brit. Mus., 1850, p. 12. Carpenter, Brit. Assn. Rept., 1863, p, 646. Tryon, Syst. Conch., Vol. Ill, p. 294, PL CXXXI, fig. 76, 1884. Cooper, 7th Ann. Repi. Cal. St. Min., 1888, p. 260. Keep, West Coast Shells, 1892, p. 163, fig. 137. Placunajiomia {Monia) macroschisma Desh., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, P- 194- , Pododesmus {Monia^ mactoscliisma Desh. ^Placunanomia ccpio Gray ^= Placitnanomia alope Gray, {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 780). ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 117 " Shell adherent, subequivalve, irregular, flattened ; hinge with two thick, divergent, elongated lamella in the inferior, corresponding with two long pits in the upper valve; upper valve with only two muscular impressions; the pedal scar radiately striated"; surface with incremental laminse and sometimes radial ridges. Part of the above description was taken from Tryon. This species resembles Anomin lampe, but may be distinguished by its greater size and fewer muscle-impres- sions. Specimen identified by Dr. Dall. Rare in the upper San Pedro series of San Pedro, Crawfish George's, and Deadman Island. Found also in the Pleistocene of the bluff west of the bath-house, at Santa Barbara. Living. — Unalaska to San Diego; Japan (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold): California; Oregon; Alaska (Dall): Santa Barbara (Arnold). Pliocene. — San Diego well (Dall)^ 2Iiocene. — Sooke, Vancouver Island (Newcombe). Genus Anomia Linne. Shell suborbicular, translucent, attached by a plug passing through a hole or notch in the right valve ; upper valve convex, smooth, lamellar, or striated ; two byssal scars on the disk, main byssal scar largest; foramen open, ample; hinge unarmed. Anomia ejyhijjpium Linne is a characteristic species. 39. Anomia lampe Gray. Anomia lampe Gray, Proc. Zool. Soc, 1849, p. 114. Carpenter, Brit. Assn. Rept., 1863, p. 646. Gabb, Pal. Cal, Vol. II, 1S69, p. 106. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 229. Keep, West Coast Shells, p. 163, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 194. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 785. Shell of medium size, suborbicular, thin, translucent and slightly pearly within; surface of left valve sculptured with fine, irregular, concentric lamellar lines and several prominent, irregular, rounded, radiating ridges; interior of this valve with submarginal cartilage pit and four muscular impressions; right or lower valve concave, with a deep rounded notch in front of the cartilage process. Dimensions. — Long, and alt. 48 mm.; diam. 9 mm. This species is variable both in regard to its shape and its sculpture, but is easily distinguisliable by the thin, lamellar, translucent shell. Distinguishable from A. limatula Dall by its smaller size and radial ridges. Specimens identified by Dr. Dall. Common in the upper San Pedro series of San Pedro, Los Cerritos, Long Beach, and Crawfish George's; rare in the lower San Pedro series of Deadman Island 118 CALIFORNIA ACADEMY OP SCIENCES. and San Pedro. Found also in tlie Pleistocene at Barlow's ranch, Ventura, and in tlie Pleistocene of Spanish Bight and Pacific Beach, San Diego. Living. — Monterey to Mexico (Cooper). Pleistocene. — San Pedro (.Cooper; Ai'nold): Ventura; San Diego (Arnold). [S. D.] Anomia limatula Dull. Anomia limahda Dall, Proc. U. S. Nat. Mu.s., Vol. I, 1879, p. 15. Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 785, PI. XXXV, fig. 19. Shell large, thin, irregular, with a rather thickened hinge-line; external surface rough, like fiesh fractured china-ware ; surface devoid of all normal radial sculpture, and still retaining on its yellowish valves traces of dark purple, irregularly radial blotches. The calcareous plug of this species is peculiar, being hollow, and the cylinder incomplete on one side. Distinguishahle from A. lampe and Pododesmiis macroschisma b}' its lack of radial sculpture. Reported in the Pleistocene of San Pedro by Stearns. Pleistocene. — San Pedro (Stearns): Ventura County, eight miles inland and two hundred feet elevation above sea-level (Bowers): Si)anish Bight and Coronado Beach, San Diego (Hemphill; Stearns): Twenty-sixth Street, San Diego (Hemphill; Arnold). Superfamily MYTILACEA. Family XII. MYTILID.T:. Genus Mytilus (Linnf) Bolten. Shell wedge-shaped, rounded behind; umbones terminal, pointed ; hinge-teeth minute or obsolete; pedal muscular impressions two in each valve, small, simple, close to the adductors. Mytilus smaragdinns Chemn. is a characteristic species. Section Mytilus .s. .s. Surface with chiefly concentric sculpture, or smooth. Type, Mytilus eduHs Linnc. 40. Mytilus edulis Linne. Mytilus edulis Linn., Syst. Nat., Ed. X, 1758, p. 705. = M. Lwrcalis Lam. = M. abbrcviatus Lam. = M. velustus Lam. = /J/, incurvatus Lam. = M. pcllucidiis Pennant = M. notatus DEK;yY = M. subsaxatilis Williamson [fide Carpenter. Brit. Assn. Rept. , 1856, p. 219). Carpenter, Brit. Assn. Rept., 1863, p. 643. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 252. Keep, West Coast Shells, p. 173, 1892. Williamson, Proc. U. S. Nat. Mus., Vol.XV, 1892, p. 191. = Modiola piilcx H. C. Lea (not of Lam.) = Mytilus minganensis Mighels, &c. {fide Dall, Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 788). Mytilus pedrmviis Con., Pac. R. R. Rept., Vol. V, 1853, p. 325, PI. V, fig. 40. ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 119 Shell of medium size, wedge-shaped, rounded behind, thin; surface smooth, except for concentric, incremental lines; umbones terminal; dorsal margin slightly depressed in middle; hinge- teeth minute. Dimensions. — Long. 55 mm.; lat. 24 mm.; diam. iS mm. The only difference between the Pleistocene specimens and the living form is in the coloraiion of the epidermis, that of the former being reddish brown, while the latter is blue. Specimens identified by Dr. Dall. Rare in the lower San Pedro series of Deadman Island; and in the upper San Pedro series of Deadman Island, Crawfish George's, and San Pedro. Living. — San Pedro (Williamson): Monterey, north; Japan; circiimpolar (Cooper): Atlantic Ocean south to North Carolina (Dall). Pleistocene. — Benicia, Solano County (Cooper): San Pedro (Arnold): Atlantic coast from Labrador to St. John's River, Florida; northern Europe; northwest coast of Ameriqa (Dall). Pliocene. — Red Crag, Great Britain (Dall). Genus Septifer Reduz. Shell equivalve, very inequilateral; ventral margin subconcave and cut out for the passage of the byssus; beaks subterminal, curved; hinge without teeth, furnished with a lamellar septum; ligamental pits linear, marginal, dorsal, anterior, with a white, nearly spongy margin within; muscu- lar impressions superficial, the anterior small, rounded, the posterior large, subdorsal, uniform. Septifer heberti Desli. is a characteristic species. 41. Septifer bifurcatus Conrad. Mylilus bifutcaliis Conrad, Journ. Phil. Acad. Sci., Vol. VII, 1837, p. 241, PI. XVIII, fig. 14. Reeve, Conch. Icon., PL IX, fig. 41. Septi/cr bifurcatus RvE., Cakpenter, Brit. Assn. Rept., 1863, p. 643. Gabb, Pal. Cal, Vol. II, 1869, p. loi. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Keep, West Coast Shells, p. 171, fig. 144, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 191. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 789. Shell small, wedge-shaped, equivalve, convex, rather thick; beaks pointed, terminal; surface sculptured by numerous strong, rounded, terminally bifurcating, radiating ridges, and fine concentric, incremental sulcations; margin corrugated; a small lamellar deck stretches across the interior of the shell near the umbo; teeth small. Dimensions. — Beak to ventral margin 10 mm.; lat. 6 mm.; diam. 4 mm. This little shell is shaped like a Mylilvs edulis, but is smaller and has prominent, bifurcating, radiating ridges, delicate incremental sculpture, and an umbonal deck. Rare in the lower San Pedro series at Deadman Island. Living. — Farallon Islands to San Diego (Cooper). Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro (Arnold). 120 CALIFORNIA ACADEMY OF SCIENCES. Genus Modiolus Lanuirck-. Shell oblong, inflated in front; umbones anterior obtuse; hinge toothless; pedal impressions three in each valve, the central elongated; epidermis often produced into long beard-like fringes. Type, Mytilus modiolus Linne. Section ilodiolus s. s. ' Surface smooth, shell inflated, edentulous, epidermis more or less hirsute. Type, Mytilus modiolus Linne. 42. Modiolus fornicatus Carpenter. Modiola fornicaia Cpr., Brit. Assn. Rep., 1863, p. 643; Ann. cS: Mag. Nat. Hist , 3rd Ser., Vul. XV, 1865, p. 179. Keep, West Coast Shells, p. 173, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 191. Shell of medium size, short, oblong, inflated in front, swollen, equivalve; beaks anterior, not quite terminal, obtuse, marginal, bent forward; surface sculptured only with concentric incre- mental lines; margins smooth; no hinge teeth. Dimensions. — Beaks to ventral margin 54 mm.; lat. 31 mm.; diam. 30 mm. This species is distinguishable by its short, swollen form. Rare in the lower San Pedro series of Deadnian Island, and in the upper San Pedro series of Los Cerritos. Found also in the Pleistocene of Bai'lovv's ranch, Ventura, and bluff west of bath-liouse, Santa Barbara. Liviny. — Monterey to Santa Barbara (Carpenter): San Pedro (Williamson). Pleistocene. — San Pedro (Ai'nold): Ventura; Santa Barbara (Arnold). 43. Modiolus rectus Conrad. Modiola recta CoN., Journ. Acad. Nat. Sci. Phil., Vol. VII, 1837, p. 243, pi. XIX, fig. i. Carpenter, Brit. Assn. Rept., 1863, p. 643. Gabb, Pal. Cal. Vol. II, p. loi, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 251. Keep, West Coast Shells, p. 171, fig. 145, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192. Dale, Trans. Wagner Inst. .Sci., Vol. Ill, Part. 4, i8yS, p. 793. Shell large, rhomboidal, narrow, evenly convex, not sharj^ly ridged, sculptured by numerous fine, concentric, incremental lines; lower margin a nearly straight line; ligament long, narrow, straight. Dimensions. — Long. 150 mm.; alt. 50 mm.; diam. 38 mm. Specimen identified by Dr. Dall. Rare in lower San Pedro series of Deadman Island, and the upper San Pedro series of Deadman Island, San Pedro, and Los Cerritos. Found also in the Pliocene of Pacific Beach, and the Pleistocene of Pacific Beach and Twenty-sixth Street, San Diego. Living. — Santa Cruz to San Diego (Cooper). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 121 Pleistocene. — San Pedro (Cooper, Arnold) : San Diego (Arnold). Pliocene. — Santa Rosa; Twelve Mile House, San Mateo County; Soquel, Santa Cruz County; San Fernando; San Diego well (Cooper): San Diego (Arnold). Miocene. — El Toro Ranch, Monterey County; Foxin's, Santa Barbara County (Cooper). Genus Lithophaga Bolten. Shell cylindrical, inflated in front, wedge-shaped behind; epidermis thick and dark; interior nacreous. Type, Mijtilus lithophagus Linne. 44. Lithophaga plumula Hanley. Lithophagus plumnla Hanley, Carpenter, Brit. Assn. Rept. , 1863, p. 644. Keep, West Coast Shells, p. 171, 1892. Williamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 192. Lilhophaga plumula Hanley, Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part. 4, 1898, p. 799. Shell subcylindric, with nearly terminal beaks; two radial sulci extending backward from the beaks, incrustation plume-like, arranged in a distinct pattern on the areas between the sulci, and, when projecting beyond the ends of the valve, apposited symmetrically. One perfect cast of a shell of this species was found on the inside of a Metis alia in the upper San Pedro series at Los Cerritos. Living. — Monterey to San Diego (Carpenter). Pleistocene. — San Pedi'o (Arnold). Order ANOMALODESMACEA. Superfamily ANATINACEA. Family XIII. PERIPLOMID.E. Genus Periploma Schumacher. Shell oval, very inequivalve, inequilateral, slightly nacreous ; left valve deepest; posterior side very short and contracted; hinge with a narrow, oblique, spoon-shaped process in each valve, and a small triangular ossicle; an internal rib proceeds from under the hinge to the posterior margin; muscular impressions unequal, the anterior long and narrow, the posterior small, semilunar; pallial impression marginal. Periploma incequivakis Schum. is a characteristic species. 45. Periploma argentaria Conrad. Periplofna argenlaria CoN., Journ. Phil. Acad. Sci., Vol. VII, 1837, p. 238, PI. XVIII, fig. 8. Carpenter, Proc. Zool. Soc, 1856, p. 211; Brit. Assn. Rept., 1863, p. 638. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 258. Keep, West Coast Shells, p. 204, fig- i75> 1892. Dall, mss., 1900. ( 11 ) December 27, 1902. 1'2'J CALIFORNIA ACADEMY OF SCIENCES. Periplo?na p/aniiiscula Sby. + P. lenlicularis Sby. = P. argcntaria CoN. = P. alta C. B. Ad = P. excurvaCPR. (fide Stearns, Proc. U. S. Nat. Mus., Vol. XIII, 1890, p. 223). Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 184. Shell of medium size, elliptical, inequilateral, inequivalve, fragile; umbones small, anterior to center; posterior extremity long and evenly rounded, but produced farthest a little above the middle; anterior portion much shorter than posterior, faintly biangulated; surface sculptured by fine concentric, incremental lines; hinge a hollow spoon-shaped process, projecting inwards from below the umbones; this cartilage process is strengthened by an elongated callus slanting anteriorly; pallial sinus short, cuneiform. Dimensions. — Long. 46 mm.; alt. 33 mm.; diam. iS mm.; umbo to anterior extremity 13 mm.; to posterior extremity 33 mm. Specimens identified by Dr. Dall. Rare in the San Pedro series of San Pedro, Los Cerritos, Crawfish George's, and Deadman Island. Found also in the Pleistocene at Twenty-sixth Street and Spanish Bight, San Diego. Living. — Point Conception south to Mexican coast (Stearns). Pleistocene. — San Pedro (Arnold): San Diego (Cooper, Arnold.) Family XIV. THRACIID.E. Genus Thracia (Leach) Blainville. Shell oblong, nearly equivalve, slightly compressed, attenuated and gaping posteriorly; smooth or minutely scabrous; cartilage process thick, not prominent, with a crescentic ossicle; pallial sinus shallow. Thracia jJubescens Pult. is a characteristic species. 46. Thracia trapezoides Conrad. Thracia trapezoides Con., Wilkes Exped., Vol. X, 1849, p. 723, Pi. XVII, fig. 6. Gabb, Pal. Cal. , Vol. II, 1869, p. 90. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 267. Shell of medium size, subtrigonal, compressed, thin ; umbones central, bent slightly posteri- orly ; anterior margin evenly arcuate from umbones, bending off quite evenly into the arcuate ventral margin; anterior extremity most produced near base; posterior dorsal margin depressed near umbo, sloping off slightly concavely to a line which abruptly truncates the posterior extremity ; this truncating line is slightly arcuate, but is angular at both ends; surface sculptured by faint incre- mental lines; a prominent fold runs from the umbones to the lower part of the truncated extremity. Dimensions. — Long. 48 mm.; alt. 38 mm.; diam. 16 mm. After comparing the San Pedro Pliocene specimens with several Miocene shells from the Astoria horizon of Blakely, Washington (Conrad's type came from this same horizon), it is evident that the two forms are identical. The San Pedro specimens, however, average much larger in size. Dr. Dall labeled these specimens ''Thracia? carta." T. carta is much less depressed behind the beaks, has a much AENOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 123 straighter ventral margin, and a more evenly ronnded anterior extremity than T. trapezoides. This species is fonnd in only one narrow stratnm of the San Pedro Pliocene. This stratnm outcrops near the base of Deadraan Island, and also on tlie top of the ridge at the head of the railroad grade in the southeastern part of San Pedro. It is the predominating species in this one stratum. Pliocene. — Eagle Prairie, Humboldt County (Cooper): San Pedro (Arnold). Miocene. — Oregon (Cooper): Blakely, near Seattle, Washington (Arnold). Family XV. PANDORIDiE. Genus Pandora. Shell inequivalve, tliin, pearly inside; valves close, attenuated behind ; right valve flat, with a diverging ridge and cartilage furrows ; left valve convex, with two diverging grooves at the hinge; pallial line slightly sinuated. Subgenus Kennerlia Carpenter. Hinge ossicle thin; radiating ribs on the right valve. Type, Kennerlia bicarinatd Carpenter. 47. Pandora (Kennerlia) bicarinata Carpenter. Plate XVIII, Fio. 2. Kennerlia bicarinata CPR., Brit. Assn. Rept., 1863, p. 638; Proc. Zool. Soc, 1S64, p. 603. Tryon, Syst. Conch., Vol. Ill, 1884, p. 143. ? Pandora bilirata Con., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257. Shell small, planoconvex, oval, thin; umbones minute, about one-third length from anterior end; anterior and posterior dorsal margins straight, making an angle a little less than 160 degrees at the umbo; ventral margin arcuate, rounding upward at each end and meeting dorsal margins in angulated turns; two posterior submargina! ridges run from the umbo to the extremity in the convex valve; surface sculpture and hinge as in K.filosa. Dimensions. — Long. 14 mm.; alt. 9 mm.; diam. 3 mm.; umbones to anterior extremity 4 mm.; to posterior extremity 10 mm. This species is closely related to K.filosa, but is distinguishable by its broader, shorter shell, rounded rather than beaked po.sterior extremity, and more nearly central umbones. Probably the same as Pandora bilirata of Conrad. One left valve from the lower San Pedro series of Deadman Island, which is 6gured, and is now in the possession of Delos Arnold. Living. — Catalina Island (Carpenter). Pleistocene. — San Pedro (Aiiiold): Santa Barbara (Cooper). 124 CALIFOENIA ACADEMY OF SCIENCES. 48. Pandora (Kennerlia) filosa Carpenter. Plate XVIII, Fig. 3. Kennerlia filosa Cpr., Brit. Assn. Rept., 1863, p. 638; Proc. Zool. Soc. , 1864, p. 602. Shell small, planoconvex, elongate-oval, thin; umbones minute, about one-fourth length from anterior extremity; anterior and posterior dorsal margins straight, making an angle of 160 degrees at the umbo; ventral margin arcuate; posterior extremity long, narrowed and truncated at the end; anterior rounded up from base but making an angle with dorsal margin ; a single prominent poste- rior, submarginal ridge runs from umbo to extremity on each valve, being nearer the margin in the flat valve; surface of both valves sculptured by numerous fine, concentric, incremental lines, and that of the right valve by fine radiating sulcations; left valve with a thin hinge ossicle; right valve with two ossicles, the anterior one being short. Dimensions. — Long. 16 mm.; alt. 7 mm.; diam. 3 mm.; umbo to anterior end 4 mm.; to posterior end 12 mm. The right valve of this little shell looks .something like a wing, and resembles Clidiophora punctata, but is distinguishable by the straight dorsal margin, radiating sulcations, and narrower form. Specimens identified by Dr. Dall. One right and one left valve found in the lower San Pedro series of Deadman Island. The specimen figured is from the lower Ban Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Puget Sound (Carpenter). Pleistocene. — San Pedro (Arnold). Genus Clidiophora Carpenter. Shell inequivalve, thin, pearly inside; valves close, attenuate behind; right valve rather tumid, with three hinge teeth, the posterior one elongated; left valve often with two teeth; ossicle present; pallial line simple. Clidiophora claviculata Carp, is a characteristic species. 49. Clidiophora punctata Conrad. Pandora punctata CoN., Journ. Phil. Acad. Sci., Vol. VII, 1837, p. 228, PI. XVII, fig. i. Clidiophora punctata Con., Cpr., Brit. Assn. Rept., 1863, p. 638. Cpr., Proc. Zoo!. Soc, 1864, p. 598. Gabb, Pal. Cal., Vol. II, p. 90, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 235. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 183. Shell rather small, suboval, much compressed, thin; umbo posterior to center, marginal, not elevated; anterior dorsal margin concavely arcuate; anterior extremity rostrated; posterior extremity evenly rounded; outer surface sculptured with fine, concentric, incremental lines; interior pearly, punctate; right valve slightly tumid, with three hinge teeth; left valve with two hinge teeth. Dimensions. — Long. 30 mm.; alt. 19.5 mm.; diam. 5 mm.; umbo to anterior end 21 mm.; to posterior end 9 mm. Specimens identified by Dr. Dall. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 125 Rare in the lower San Pedro series of Deadmaii Island and upper San Pedro series of San Pedro. Found also at Spanish Bight, San Diego. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — San Pedro (Arnold): San Diego (Arnold). Pliocene. — San Benito County (Coojjer). Miocene. — Ventura Count}' (Cooper). Family XVI. LYONSIID.E. Genus Lyonsia Tiirfon. Shell nearly equivalve, left valve largest; thin, subnacreous, close, truncated posteriorly; cartilage plates oblique, covered by an oblong ossicle; pallial sinus obscure, angular. Lyonsia norvegica is a characteristic species. 50. Lyonsia californica Conrad. Lyonsia californica Con., Journ. Phil. Acad. Sci., Vol. VII, 1837, p. 248, PI. XIX, fig. 20. Cpr., Proc. Zool. Soc, 1856, p. 210; =L. bracteata Gld. =Z-. iiitida Old., {fide Carpen- ter, Brit. Assn. Rept., 1863, p. 638). Keep, West Coast Shells, p. 202, fig. 174, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 184. Shell of medium size, elongate-oval, truncated and narrowing slightly posteriorly, convex, thin; long, slightly depressed posterior to umbo; short, convex anterior; surface sculptured with fine, concentric, incremental lines; external layer chalky and fugacious, pearly beneath; cartilage- plates oblique, covered by an oblong ossicle; pallial sinus obscure. Ditnensions. — Long. 31 mm.; alt. 14 mm.; diam. 11 mm. This frail shell is generally found with the outer layer gone, leaving the pearly surface of the lower layer exposed. Outline variable. Specimens identified by Dr. Dall. Rather common in the Pliocene of Deadman Island, the lower San Pedro series of Deadman Island and San Pedro, and the upper San Pedro series of Dead- man Island, Crawfish George's, and San Pedro. Living. — Puget Sound to San Diego (Carpenter). Pleistocene. — San Pedro (Arnold). Pliocene. — San Pedro (Arnold). Genus Mytilimeria Conrad. Shell rounded oval, more or less ventricose, equivalve, fragile, covered by a thin caducous epidermis; beaks subspiral; hinge without teeth, but formed of small linear excavations under the beaks to receive the ligament, which contains a small ossicle; muscular impressions small; pallial impression with an obtuse sinus. Type, Mytilimeria nvttalli Conrad. 12G CALIFORNIA ACADEMY OF SCIENCES. 51. Mytilimeria nuttalli Conrad. Plate XVII, Fig. 8. Mytilimeria tnMa/ii Con., }ourn. Phil. Acad. Sci., Vol. VII, 1837, p. 247. Cpr., Brit. Assn. Rept., 1863, p. 638. Gabb, Pal. Cal., Vol. II, p. 90, 1869. Tryon, Syst. Conch., Vol. Ill, 1884, p. 147, PI. CVIII.fig;. 68. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 252. Keep, West Coast Shells, p. 203, 1892. Shell small, equivalve, suboval, convex, thin; beaks central, subspiral, small; surface sculp- tured by fine, concentric, incremental lines and numerous delicate radiating sulcations, the whole having a pearly luster; hinge edentulous, with a slight linear cavity under the beaks; pallial sinus broad, obtuse. Divicnsio7is. — Long. 11 mm.; alt. 17 mm,; diam, 10 mm. Thi.s fragile little shell resembles a very small and broad Mytilns, but is easily distinguishable by its delicate scnlptnre. Specimens identified by Dr. Dall. Rare in the Pliocene and lower San Pedro series of Deadman Island, and in the lower San Pedro series of San Pedro. The species figured is imperfect. It came from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Straits of Fnca to San Diego (Cooper). Pleiaiocene. — San Pedro (Cooper; Arnold). Miocene. — Tomales, Marin County (Cooper). Superfamily POROMYACEA. Family XVII. VERTICORDIIDiE. Genus Verticordia S. Wood. Shell suborbicular, with radiating ribs; beaks subspiral; margins denticulated; interior brilliantly pearly; hinge with one prominent cardinal tooth in each valve; adductor scars two, faint; pallial line simple; ligament internal, oblique; epidermis dark brown. Type, Verticordia cardiiformis Wood. 52. Verticordia novemcostata Adumi^ <£• Reeve. Plate XVII, Fig. 10. Verticordia nove^ncostata Ad. & RvE,= V. oriiata D'Orb. (yza'f Cpr., Brit. Assn. Rept., 1863, p. 645.) Shell small, suborbicular, compressed, thin; beaks subcentral, subspiral, small, sharp, anterior extremity evenly rounded; posterior dorsal margin evenly arcuate, and joining arcuate ventral margin in an angular extremity; surface with nine prominent, sharp, arcuate, radiating ridges; the first and third interspaces wider than the others; margins sharply denticulate; liinge with one prominent cardinal tooth in each valve; adductor scars two, faint; pallial line simple; ligament internal, oblique; interior pearly. Dimensions. — Long. 4 mm.; alt. 3.5 mm.; diam. 2 mm. ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 127 This little shell is one of the unique species of this fauna. Specimens identi- fied by Dr. Dall. One specimen from lower San Pedro series of Deadman Island, which is figured, and is now in the collection of Delos Arnold. Living. — Santa Barbara; Samarang, China; South America (Carpenter): San Pedro (Raymond). Pleistocene. — San Pedro (Arnold). Order TELEODESMACEA. Superfamily ASTARTACEA. . Family XVIII. , ASTARTID.E. Genus Astarte Soiverby. Shell suborbicular, compressed, thick, smooth, or concentrically furrowed; lunule com- pressed; ligament external; epidermis dark; hinge-teeth two in each valve, the anterior tooth of the right valve large and thick ; anterior pedal scar distinct ; pallial line simple. Astarte semisulcata Leach is a characteristic species. Subgenus Crassinella Bayle. Shell obliquely lengthened, subquadrangular. Astarte ohliqua Dash, is a characteristic species. 53. Astarte (Crassinella) branneri, sp. nov. Plate XVIII, Fig. 12. Shell small, subtrigonal, equivalve, inequilateral, convex, thick; umbo small, sharp; ante- rior dorsal margin straight to anterior extremity, where it meets the arcuate ventral margin in an angle ; posterior dorsal margin evenly arcuate, sloping down to rounded, posterior extremity ; surface sculptured with numerous angular, concentric undulations or ridges ; lunule long, narrow, extending to anterior extremity, and circumscribed by a narrow, angular ridge ; ligament external, not promi- nent; two prominent cardinal teeth in right valve; one in lelt; no laterals; pallial line entire, running from the middle of adductor scars ; adductor scars subequal, small. Dimensions. — Long. 10 mm.; alt. 8.9 mm.; diam. 5 mm. This species somewhat resembles Astarte compacta Cpr., but has a longer lunule, finer concentric ridges, and is more bilaterally symmetrical. Specimens pronounced a new species by Dr. Dall. Named in honor of Dr. John C. Branner, Professor of Geology, Leland Stanford Junior University. Rare in the upper San Pedi'o series of San Pedro and Los Cerritos. The specimen figured is the type, which is from the ujijier San Pedro series at Los 128 CALIFORNIA ACADEMY OF SCIENCES. Cerritcs, ■ and i.s iiow in tliu United State.s National Museum. Found also in the Pleistocene of Twenty-sixth Street, Sau Diego. Pleistocene. — San Pedro; San Diego (Arnold). Superfamily CARDITACEA. Family XIX. CAKDITID.E. Genus Venericardia Lamarck. Shell siiborbicular, inequilateral, radiately ribbed; hinge widi two oblique cardinal teeth and no laterals. Venericardia planicostata Lamarck is a characteristic species. 54. Venericardia barbarensis Stearns. Venericardia barbarensis Stearns, Proc. U. S. Nat. Mus., Vol. XIII , 1891, p. 214, PI. XVI, figs. 3, 4. Shell rounded, inequilateral, variable in outline, more or less oblique, moderately convex; beaks small, slightly elevated and turned forward; surface ornamented with nineteen or twenty radi- ating ribs, usually somewhat granulose; lunule small, slightly sunken, faintly defined; hinge-line small, not thick ; hinge composed of, in' left valve, a single strong cardinal sloping posteriorly and a smaller tooth, often obscure, slanting anteriorly; a third tooth-like process is generally present, situated under, and apparently a projection of, the edge of the lunule; the right valve has a single strong cardinal tooth with a slanting, somewhat sinuous groove above and a slight notch and tooth- like point below the upper part of the lunule; muscle impressions small. Diiuensiofis. — Long. 19.5 mm.; alt. 17 mm.; diam. 14 mm. Distinguishable from I', ventricosa by more subrectangular outline, greater relative length; greater number of ribs, less prominent beak, much narrower and longer hinge-line, and shorter, slighter posterior cardinal tooth, which is straight. Common in Pliocene and lower San Pedro series of Deadman Island; rare in Pliocene at Timm's Point and upper San Pedro series of Crawfish George's and San Pedro. Found also west of bath-house at Santa Barbara. Living. — Santa Barbara Islands (276 fathoms) (Stearns). Pleistocene. — San Pedro (Arnold): Santa Barbara (Arnold). Pliocene. — San Pedro (Arnold). 55. Venericardia venti-icosa Gim/d. Cardila ventricosa Gi^u., Proc. Bost. Soc. Nat. Hist., 1850, p. 276; Wilkes Hxpl. E.x[)ed., Vol. XII, p. 417, PI. XXXVI, fig. 532, 1852, =C. subte7ita Con., =C. monilicosta Gabb, ^C. occi- dentalis Con., {fide Gabb, Pal. Cal., Vol. II, 1869, p. 100). Venericardia borealis \-3S . ventricosa Gld., Cpr., Brit. Assn. Rept., iS63,ix 643, Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 269. Veiiericardia veyitricosa Gld., Stearns, Proc. U. S. Nat. Mus., Vol. XIII, 1891, p. 216, PI. XVI, figs. 5 and C. W1LLIAM.S0N, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 129 Shell small, subcircular, ventricose, thick ; umbones slightly anterior to center, much bent forward, prominent; surface sculptured by about thirteen prominent, rounded, radiating ridges, which are slightly roughened by regular lines of growth; sulcations narrow; hinge area broad, short; two prominent teeth in each valve, anterior short; margin closely crenulated. Dimensions. — Long. 12.5 mm.; alt. 13 mm.; diam. 8 mm. Distingui.shable by small size, coarse sculpture and heavy hinge. Common in the Pliocene of Deadman Island and Timin's Point; rare in lower San Pedro series of Deadman Island. Found also in Pleistocene of Pacific Beach, near San Diego; and in the Pliocene of Packard's Hill and the Pleistocene near the bath-house, Santa Barbara. Living. — Alaska to Cataliua Island (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa Bar- bara; San Diego (Arnold). Pliocene. — San Fernando; Santa Barbara to San Diego (Cooper): San Pedro; Santa Barbara (Arnold). Miocene. — Oregon; Foxin's, Santa Barbara County; Santa Monica (Cooper): Blakeley, near Seattle, Washington (Arnold). Genus Lazaria Conrad. Shell transverse, oblong, inequilateral; beaks subanterior, radiately ribbed ; hinge with two cardinal and two lateral diverging teeth in each valve, the posterior teeth being in each case much elongated, the anterior short and more or less pointed, sublunular. Lazaria pectunculus Brug. is a characteristic species. 56. Lazaria subquadrata Carpenter. Lazaria subquadrata Cpr., Brit. Assn. Rept., 1S63, p. 642; Ann. Mag. Nat. Hist., 3d ser.. Vol. XV, 1865, p. 179. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 244. Keep, West Coast Shells, p. 179, fig. 152, 1892. Williamson, Proc. U. S. Nat. Mus.,Vol. XV, 1892, p. 190. Shell small, transverse, subrectangular, inequilateral, ventricose, thick; beaks subanterior, not prominent ; dorsal posterior margin long, straight ; anterior portion abruptly truncated just in front of beak; surface sculptured with heavy, squamose, rounded, radiating ridges; interior margin coarsely crenulated; hinge with two lateral diverging teeth in each valve, the posterior teeth being in each case much elongated, the anterior short and pointed. Dimensions. — Long. 10 mm.; alt. 6 mm.; diam. 5.6 mm. Distinguishable by its small size, rectangular outline, and coarse, squamose ridges which radiate from one corner of the rectangle. Specimens identified by Dr. Dall. Rare in the lower San Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series of Crawfish George's and San Pedro. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). ( n ) December 29, 1902. 130 CALIFOKNIA ACADEMY OF SCIENCES. ■Superfamily CHAMACEA. Family XX. CIIAMID.E. Geuus Chama {Plimj) Linne. Shell attached usually by the left umbo; valves foliaceous; the ujjper smallest; hinge-tooth of free valve thick, curved, received between two teeth in the other; adductor impressions large; oblong, the anterior encroaching on the hinge-tooth. Chama lazarus Linne is a characteristic species. 57. Chama exogyra Conrad. Chama exogyra Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 256. Reeve, Conch. Icon., sp. 38, PI. VII. Carpenter, Proc. Zool. Soc, 1856, p. 217; Brit. Assn. Rept., 1863, p. 641. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 233; Bull. Cal. St. Min. Bureau, No. 4, 1894. p. 24. Keep, West Coast Shells, p. 182, 1892. Williamson, U. S. Nat. Mus., Vol. XV, 1892, p. 189. Shell of medium size, oval, irregular; left valve subcompressed, thick, attached when living; umbo small, submarginal, much twisted, either de.\tral or sinistral, generally the former; surface foliated with irregular, disconnected, rough, translucent, concentric frills; hinge-tooth thick in free valve; two teeth in attached valve; adductor impressions large, oblong, the anterior encroaching on the hinge-tooth. Dimensions. — Long. 33 mm.; alt. 33 mm.; diam. 16 mm. Distinguishable from C. fMucida by larger, thicker shell, fewer and less spiny, though more prominent frills; and by being attached generally by the left valve. Specimens identified by Dr. Dall. Rare in upper San Pedro series of San Pedro and Los Cerritos. Living. — Bodega Bay to San Diego; Mexico (Cooper). Pkidocene. — Santa Barbara to San Pedro (Cooper): San Pedro (Arnold): San Nicolas Island (Bowers). 58. Chama pellucida Soiverbi/. Chama spinosa Brod. vi,x. pellucida Sv.y., Proc. Zool. Soc, 1834, p. 150. Chama pellucida Sby., Cpr., Brit. Assn. Rept., 1S63, p. 641. Keep, West Coast Shells, p. 182, fig. 155, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 189. Cooper, Bull. Cal. St. Min. Bureau, No. 4, 1894, p. 24. Shell of medium size; right valve (attached), exceedingly ventricose, rather thin; left valve nearly flat, thicker; surface of attached valve sculptured with numerous prominent, spiny frills; surface of upper valve with more numerous, small frills, which are sometimes spiny near the margin of the valve; hinge-teeth and muscle-impressions as in C. exogyra. Dimensions. — Long. 20 mm.; alt. 25 mm.; diam. 15 mm. Distinguishable from C. exogyra by smaller size, more prominent frills on upper valve, and by the fact that in C. pellucida the right valve is generally attached, ■Hid is exceedingly ventricose, while in 0. exogyra the left valve is the larger, and is attached. Specimens identified by Dr. Dall. ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHY OF SAN PEDRO. 131 Rather common in the Pliocene; rarer in the lower San Pedro series of Dead- man island; and only found occasionally in the upper San Pedro series of San Pedro, Deadman Island, Los Cerritos, and Crawfish George's. Living. — San Francisco to San Diego (Carpenter). Pleistocene. — San Pedro (Arnold). Pliocene. — Ventura County (Bowers). Superfamily LUCINACEA. Family XXI. LUCINIDJ^I Genus Lucina Brugih-e. Shell orbicular, white; umbones depressed; lunule distinct; margins smooth or minutely crenulated ; ligament oblique, semi-internal; hinge-teeth two in each valve; laterals, two in right valve, four in left ; muscular impressions rugose ; anterior elongated within the pallial line, posterior oblong; umbonal area with an oblique furrow. Lucina jamaicensis Linne is a characteristic species. 59. Lucina acutilineata Conrad. Lucina acutilineata Con., Wilkes Expl. Exped., Vol. X, p. 725, PI. XVIII, fig. 2, 1849. Cyclas acutilineata Con., Jour. Conch., 1865, p. 153. Lucina borealis (not of Linn.BUS, Syst. Nat., Edition XII, p. 1413); of Cpr., Brit. Assn. Rept., 1863, p. 643; ^= Pectunculus patulus Con., Jour. Conch., 1865, p. 153; not Wilkes Expl. Exped., p. 726 PI. XVIII, fig. 9; =^Lucina tetrica CoN. {fide Gabb, Pal. Cal., Vol. II, p. 100, 1869). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 246. Shell large, orbicular, only slightly convex, rather thin; umbones depressed, central; surface ornamented by numerous equal, equidistant, sharp, raised, concentric lines; interspaces show lines of growth; lunule small, but deeply impressed and distinct; two sharp cardinal teeth in each valve; lateral teeth nearly obsolete; anterior muscle-impression much elongated. Dimensiojis. — Long. 57 mm.; alt. 53 mm.; diam. 28 mm. This species is easily distinguishable by its large size and sharp, concentric, raised lines. This beautiful shell is always found in a fine .state of preservation in the Deadman Island formations, in many cases occurring in pairs. The .shell is translucent, and in only a few instances have imperfect specimens been found. The convexity of the shell is slightly variable, being more in the younger shells, the older ones being inclined to become flatter. The Pliocene specimens are smaller, more convex, and have the concentric lines much closer set than do the Pleistocene forms. Sjiecimens identified by Dr. Dall. Common in Pliocene and lower San Pedro series of Deadman Island and San Pedro; rare in the upper San Pedro series of Deadman Island, Crawfish George's, and San Pedro. Only one or two specimens have been found in each of the upper San Pedro localities; thus practically restricting the northern species to the Pliocene and 132 CALIFORNIA ACADEMY OF SCIENCES. lower San Pedro series. Found also in the Pleistocene west of bath-house, Santa Barbara; and in the Pleistocene of Pacific Beach, San Diego. Living. — Catalina Island (Cooper) : Santa Barbara channel (Carpenter) : Puget Sound (Arnold). Pleistocene. — Santa Barbara to San Diego (Cooj)er) : San Pedro; Santa Bar- bara; San Diego (Arnold). Pliocene. — Santa Rosa; Santa Cruz; Sargent's, Santa Clara County; Santa Barbara; San Fernando; San Diego well (Cooper): Stanford University (Arnold). Miocene. — Oregon; Martinez; Griswold's, San Benito County; Orestima Can- yon, Stanislaus County; Foxin's, Santa Barbara County (Cooper): Point Blakely, near Seattle, Washington (Arnold). 60. Lucina calif ornica Conrad. Liicina californica CoN.,Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 255, PI. XX, fig. I. CPR., Brit. Assn. Rept., 1863, p. 642. Gabb, Pal. Cal., Vol. II, 1869, p. 100. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 247. Keep, West Coast Shells, p. 178, fig. 151, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. Shell of medium size, orbicular, only slightly conve.x, rather thick; umbones depressed, central; surface ornamented with numerous fine, close- set, sharp, concentric lines and very faint, fine, radiating strife; lunule small but distinct, deep-set, wholly in right valve; ligament prominent; two cardinal teeth in each valve ; two prominent anterior, lateral teeth in left valve, one in right valve, other laterals small ; muscle-impressions as in L. acutilineaia. Dimensions. — Long. 31 mm.; alt. 29 mm.; diam. 16 mm. Distinguishable from L. acutilineaia by smaller size, close-set, concentric lines, and having the lunule wholly within the right valve. Found in the Pliocene of Deadraan Island; in the lower San Pedro series of Deadraan Island and San Pedro; and rarely in the upper San Pedro series at Craw- fish George's, San Pedro, Los Cerritos, Deadman Island, and Long Beach. Found also in the Pleistocene at the bath-house, Santa Barbara, and in the Pleistocene of Pacific Beach, San Diego. Living. — Santa Cruz to San Diego (Cooper). Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro; Santa Bar- bara; San Diego (Arnold). 61. Lucina nuttalli Conrad. Lucina nnttalli Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 255, fig. 2, PI. XX. Cpr., Brit. Assn. Rept., 1863, p. 642. Gabb, Pal. Cal., Vol. II, p. 100, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 247. Keep, West Coast Shells, p. 179, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. Shell small, orbicular, only slightly convex, thin; umbones depressed, small, central; surface ornamented by numerous sharp, regular, concentric lines and prominent radiating grooves, which are most prominent near the ends, the whole giving a rather cancellated appearance to the surface; lunule small, nearly all in left valve; hinge and interior as in Z,. californica. Dimensions. — Long. 20 mm.; alt. 20 mm.; diam. 10 mm. AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 133 Distinguishable by small size, cancellated surface, and luniile in left valve. Specimens identified by Dr. Dall. Common in the lower San Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's, Deadman Island, and Long Beach. Found also in the Pliocene of Pacific Beach, and the Pleistocene of Twenty-sixth Street and Pacific Beach, San Diego. Living. — Monterey to San Diego (Cooper). Pleistocene. — Santa Barbara; San Pedro (Cooj)er) : San Pedro; San Diego (Arnold). Pliocene. — San Diego (Arnold). 62. Lucina tenuisculpta Carpenter. Lucina tenuisculpta Cpr., Brit. Assn. Rept., 1S63, p. 642. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 247. Shell small, orbicular, deeply convex, thin; umbones prominent, central ; surface sculptured by numerous fine, concentric lines and radiating striae; lunule prominent, the greater part being in the right valve; cardinal teeth small, laterals prominent ; anterior muscle-impressions not as elongated as in L. acutilineata and others. DimensioJis. — Long. 9 mm.; alt. 8.8 mm.; diam. 6.4 mm. Distinguishable by small size, sculptured surface, and great convexity. This sjiecies resembles Diplodonta orhella very closely in shape and size, but may be distinguished by the lack of jirominent cardinal teeth, by its lateral teeth, and by the radiating striae. Specimens identified by Dr. Dall. Rare in the upper San Pedro series of San Pedro. Found also in the Pleis- tocene of Spani.sh Bight, San Diego. Living. — Straits of Fuca to Catalina Island; Mazatlan (Cooper). Pleistocene. — San Pedro; San Diego (Arnold). Pliocene. — San Diego well (Dall). Family XXIL DIPLODONTID^. Genus Diplodonta Brown. Section Diplodonta s. s. Shell rotund, equilateral, externally concentrically striated or smooth, with inconspicuous epidermis; two cardinal teeth in each valve, of which the right posterior and the left anterior are distally sulcate or bifid; no lateral teeth; the hinge-plate when developed is usually excavated distally- there is no circumscribed lunuIe or escutcheon; the adductor scars are subequal, continuous with the pallial line, and close to the hinge-plate; the margin is entire, the pallial line simple, and pallial area often radiately striate. Type, Diplodonta hqnnus Brocchi. 134 CALIFORNIA ACADEMY OF SCIENCES. 63. Diplodonta orbella Gould. Plate XVIII, Figs. 8 and 8rt. Lticina orbella Gld. , Proc. Bost. Soc. Nat. Hist., Vol. IV, 1851, p. 90; Bost. Jour. Nat. Hist., Vol. VI, 1853, p. 395, PI. XV, fig. 3; Cal. & Mex. Shells, p. 22, PI. XV, fig. 3. Diplodonta orbella Gld., Gould & Carpenter, Proc. Zool. Soc, 1856, pp. 202, 218. '=( Mysia) Sphairella tumida CoN. {Jide Cpr., Brit. Assn. Rept. , 1863, p. 643). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 238. Keep, West Coast Shells, p. 179, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1189. Shell small, subglobose, thin; beaks nearly median, not prominent; surface sculptured with fine incremental lines, which at some parts are more conspicuous than at others and render the surface somewhat irregular; no distinct lunule; ligament prominent; two cardinal teeth in right valve, of which the anterior is smallest, and the posterior bifid; and two in the left valve, of which the anterior is bifid, and the posterior very oblique; no lateral teeth; muscle-impressions large, faint. Dimensions. — Long. 11. 9 mm.; alt. 11. 9 mm.; diam. 9 mm. Kesembles Lucina tenuiscidpia, but may be distinguished by lack of radiating stria?, and by the prominent cardinal teeth and hick of lateral teeth. Sjiecimens identified by Dr. Dall. Rare in the lower San Pedro series at Deadman Island; and the upper San Pedro series of San Pedro and Crawfish George's. Found also in the Pleistocene of Twenty-sixth Street, San Diego. The specimen figured is from the lower San Pedro series of Deadman Island, and is now in the collection of Delos Arnold. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego (Arnold). Pliocene. — San Diego well (Dall). 64. Diplodonta serricata Reeve. Plate XVIII, Fios. 5 and 5n. Diplodonta serricata Rye., Cpr., Brit. Assn. Rept., 1S56, p. 248. Shell small, orbicular, only slightly convex, thin; umbones central, not prominent ; surface sculptured with numerous fine, incremental lines, which are regular in prominence; lunule not distinct; hinge prominent; teeth and interior as in D. orbella. Dimensions. — Long. 13.8 mm.; alt. 14 mm.; diam. 7 mm. Distinguishable from D. orhclla by its much less convexity and more regular concentric lines. Specimens identified by Dr. Dall. Not uncommon in the upi^er San Pedro series of San Pedro. This species is very common in the Pleistocene deposits at Twenty-sixth Street, San Diego. The specimen figured is from this horizon, and is now in the collection of Delos Arnold. Living. — Mazatlan (Carpenter). Pleistocene. — San Pedro; San Diego (Arnohl). ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDKO. 135 Family XXIII. CRYPTODONTID^E. Genus Thyasira Leach. Shell globular, posterior side furrowed or angulated; umbones much recurved; lunule short or indistinct; ligament usually and to a certain extent external, placed in a groove on the hinge-line, and outside the hinge-plate; teeth altogether wanting. llujaslra Jiexuosus Mont, is ;i characteristic species. 65. Thyasira bisecta Conrad. Platf, XV. Fig. 5. Venus bisecta Con., Wilkes Expl. Exped., Vol. X, App. i, p. 724, PI. XVII, figs. 10, loa, 1849. Thyatira? bisecta Con., Meek, Smithsonian Inst., Check-List Mioc. Fossils, 1864. Cyprina bisecta Co*i., Jour. Conch., 1S65, p. 153. Conchocele bisecta CoN. Gabb., Pal. Cal., Vol. II, p. 99, 1869. Coyichoccle disjuncta Gabb, Pal. Cal., Vol. II, pp. 28, 29, PI. VII, fig. 48, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 236. Cryptodon bisectus Con., Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 189; Vol. XVII, 1894, P- 713, PI. XXVI, figs. 2-5. Shell large, subquadrate, convex, of medium thickness, equivalve, inequilateral ; beaks terminal, anterior; anterior end abruptly and angularly truncated; posterior dorsal margin arcuate, sloping down toward posterior extremity; surface marked only by lines of growth except near the posterior part, where the peculiar truncation takes place, the surface suddenly descending at right angles to the curve of the shell, for a short distance, and then resuming its former direction ; ligament long and elliptical; large lunular area in front of the beaks. Dimensions. — Long. 72 mm.; alt. 62 mm.; diam. 41 mm. Specimens identified by Dr. Dall. Gabb describes this shell as occurring in the Miocene of Deadmau Island, while Cooper gives its occurrence as in the " Quaternary " of the same place. It is found most abundantly in a hard stratum near the base of the Deadraan Island Pliocene deposits; a few shells, however, have been found in Pliocene strata above this layer; found also at Timm's Point in the Pliocene. Tlie specimen figured is from the Pliocene of Deadman Island, and is now in the collection of Delos Arnold. Living. — Paget Sound, sixty-nine fathoms (Dall). Pliocene. — San Pedro (Arnold). Miocene. — Astoria, Oregon (Conrad): Blakely, near Seattle, Washington (Arnold). 66. Thyasira gouldi Philippi. Cryptodon flexuosHs (not of Montagu) of Carpenter,- Brit. Assn. Rept., 1S63, p. 643. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 237. Shell small, globular, posterior side angulated or furrowed ; umbones much recurved ; sur- face sculptured with fine incremental lines ; lunule indistinct, depressed in front of beaks ; ligament external, placed in a groove on the hinge-line and outside the hinge-plate ; teeth wanting. Dimensions. — Long. 9.5 mm.; alt. 11 mm.; diam. 8 mm. 136 CALIFORNIA ACADEMY OP SCIENCES. This species is distinguishable from T. biaecta by its much smaller size, more central umbones and less prominent lunule. Dr. Dall says that 2\ gouldi has been mistaken for Cryptodon flexuosus by West Coast collectors. Rather common in the Pleistocene of Dead Man Island and Timm's Point. Not found above the horizon in the San Pedro deposits, so far as known. Living. — Catalina Island (Cooper): Catalina Island, ten fathoms (Arnold). Pleistocene. — Santa Barbara (Cooper). Pliocene. — Santa Barbara; San Diego well (Cooper): San Pedro (Arnold). Superfamily LEPTONACEA. Family XXIV. LEPTONID^. Genus Bornia I'hiUjrpl. Shell ovate or subtrigonal, subequilateral, with a more or less flattened disk; the peri- ostracum usually brilliant; the surface smooth or divaricately more or less plicate; pallial line not sinuated, and the pallial area piquantly punctate or radially striate; hinge with one moderately long posterior, and two shorter anterior, lamina- in the left valve; in the right, one anterior and one longer, sometimes remote, posterior lamina; one or both of the anterior laminae in either valve may have the aspect of cardinals; hinge-plate usually excavated. Ty2:)e, Bornia corhuloides (Phil.). 67. Bornia retifera Dull. Plate XVII, Fig. 12. Bornia retifera Dall, Proc. U. S. Nat. Mus., Vol. XXI, 1899, p. 889, PI. LXXXVII, fig. 2. Shell thin, white, moderately conve.x, rounded, trigonal, nearly equilateral; beaks distinct, not high; surface polished, with faint incremental lines and minute, close punctations whose inter- spaces give the effect of a fine netting ; hinge narrow, delicate; one tooth opposite beak, then a depression posterior to this, and then a second tooth completely filling the anterior end of the posterior ligamental groove; adductor scars rounded and high up. Dimensio7is — Long. 7 mm.; alt. 5.5 mm.; diam. 3 mm. Looks like a Kellla laperou»ii, but is distinguishable by the microscopic sculpture and hinge. Specimens identified by Dr. Dall. One right valve from the lower San Pedro series of Deadman Island, which is figured herewith, and is now in the collection of Delos Arnold. Living. — Station 2,900, thirteen fathoms, off Santa Barbara (Dall). Pleistocene. — San Pedro (Arnold). Genus Kellia Turton. Section Kellia Turtou a. s. Shell rounded and inflated, concentrically striated or smooth ; with an obsolete external ligament and a large internal resilium without a lithodesma ; two anterior and two posterior teeth in ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 137 each valve, of which the anterior ones are shorter and may be concrescent or free and pustular ; interior of valves commonly shows radial striation; and valves frequently distorted. Type, Kellia suborbicularis (Montagu). 68. Kellia laperousii Deshayes. Pl.ate XVIII, Figs. 7 and la. Kellia laperousii Desh., Carpenter, Brit. Assn. Rept., 1863, p. 6+3. Keep, West Coast Shells, p. 178, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 191. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1155. Shell of medium size, suborbicular, convex, thin; umbones slightly anterior, not prominent; surface sculptured by fine incremental lines which are slightly variable as to prominence; no lunule; each valve with one very prominent cardinal tooth ; right valve with two posterior laterals, left with one; hinge-area lacking between cardinal and lateral teeth; muscle-impressions not distinct. Dimensions. — Long. 23 mm.; alt. 19 mm.; diam. ii mm. Di3tingai.shable from K. suborbicularis by its larger size and less convexity. These two species may be recognized by their thin, suborbicular shells, and the lack of a hinge-area in the region of the uiubones, the vacancy at first giving the impres- sion that the hinge-area has been broken. Specimens identified by Dr. Dall. Rare in lower !San Pedro series of San Pedro and Deadman Island. One perfect valve from the Pliocene at Deadman Island. Found also in the Pleistocene of Spanish Bight, San Diego. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Puget Sound to Monterey (Carpenter). Pleistocene. — San Pedro (Arnold): San Diego (Arnold). Pliocene. — San Pedro (Arnold). 69. Kellia suborbicularis Montatju. Plate XVIII, Figs. I and la. Kellia suborbicularis Mont., Testacea Britannica, pp. 39, 564, PI. XXVI, fig. 6, 1804. Carpenter, Brit. Assn. Rept., 1863, p. 643. Tryon, Syst. Conch., Vol. Ill, p. 220, PL CXX, fig. 2, 1884. Keep, West Coast Shells, p. 177, 1892. William.son, Proc U. S. Nat. Mus., Vol. XV, ,1892, p. 191. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. II 55. Shell small, suborbicular, deeply convex, thin; beaks small, slightly anterior; surface orna- mented with fine lines of growth which become somewhat irregularly constricted near margin, roughening the surface; no lunule; margins smooth; hinge and teeth as in K laperousii. Dimensions. — Long. 8.4 mm.; alt. 7.4 mm.; diam. 5.8 mm. Distinguishable from K. laperousii by smaller size and greater convexity. Specimens identified by Dr. Dall. Rare in lower San Pedro series of San Pedro and Deadman Island. The ( 18 ) December 31, 1902. 138 CALIFOKNIA ACADEMY OF SCIENCES. specimen fii^urecl is from tlie lower San Petlro series at Deachnaii Island, and is now in the collection of Delos Arnold. Living. — Puget Sound to Lower California; England (Carpenter). Pleistocene. — San Pedro (Arnold). Funiily XXV. KELLIELLID.E. Genus Aligeua //. G. Lea. Shtll rounded, triangular, inflated; single small anterior tooth under the beaks, separated by a gap from the surface ot attachment, under the posterior dorsal margin, of an elongate internal resilium carrying a lithodisma. Type, Aligeua striata (Lea). 70. Aligena cerritensis, sp. no v. Plate XIII, Fig. 3. Shell small, rounded, triangular, inflated, thin; inequilateral, the umbo being nearly terminal posteriorly; anterior dorsal margin nearly straight; anterior extremity quite sharply rounded and produced furthest below middle; posterior extremity sloping off abruptly from umbo and rounded near base; ventral margin arcuate; surface with faint concentric sculpture; umbones small, pointed, anteriorly twisted, with a minute tooth below them on the cardinal margin; pallial line entire; muscle- scars subequal. Dimensions. — Long. S.5 mm.; alt. 8 mm.; diam. 5 mm. This species resembles Acila castrensis in outline. Specimens identified by Dr. Dall, who pronounced it a new species. Two specimens from the upper San Pedro series of Los Cerritos, one of which is the type, which is figured, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Superfamily CARDLVCEA. Funiily XXVI. GARDIID/E. ■ Genus Cardium (Linne) Lamarck. Shell variably sculptured, usually with predominantly radial ornamentation, usually closed or gaping but slightly, with no lunula or escutcheon ; pallial line rather distant from the margin of tile valves. Subgenus Trachycardium March. Shell rotund, closed, with the ribs imbricate or granulose; the channels also sometimes granulose ; left cardinals anterior when interlocked. Type, Cardium iAnrarilia (Liiinc). AENOLD— THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDRO. 139 71. Cardium (Trachycardium) quadrigenarium Conrad. Cardt7im qtiadrigenarUim CoN., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 230, PI. XVII, fig. 5; = Inteolabriim Gld. (tJo'i? Carpenter, Brit. Assn. Rept., 1863, p. 642). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, page 232. Keep, West Coast Shells, p. 192, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part. 5, 1900, p. 1091. Shell large, oval, ventricose, thick; umbones central, prominent, turned only slightly an- teriorly; surface sculptured with about forty prominent, subangular, smooth, radiating ridges, which are roughened by prominent pointed tubercles on their posterior angle; those ridges near the pos- terior margin are less prominent, but are nodose for nearly their whole length; teeth and interior as in C. cordis: margin sharply serrated. Dimensiotis. — Long. 105 mm.; alt, 105 mm.; diam. 86 mm. Distinguishable by laro;e .size and tuberculated ridges. Specimens identified by Dr. Dall. Found in the upper San Pedro series of San Pedro, Los Cerritos and the Long Beach bluff. Found also in the Pleistocene of Twenty-sixth Street and Pacific Beach, San Diego. Living. — Monterey to San Diego (Cooper). Pleistocene. — San Pedro (Arnold): San Diego (Cooper; Arnold). Pliocene. — Calleguas Ranch, Ventura County (Cooper). Subgenus Ringicardium Fischer. Shell rotund, gaping, with flat ribs and channels, the posterior area with granulose channels; posterior margin sharply spinose, the spines crossing each other over the gap; left cardinals when interlocked posterior to the right ones. Type, Cnrdium ringens (Gmel.). 72. Cardium (Ringicardium) procerum Sowerhy. Plate XV, Fig. 6. Cardmm p7-occrui>i Sby., Carpenter, Brit. Assn. Rept., 1863, p. 620. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1091. Cardmm panamense , not of Sby., of Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 232. Shell of medium size, suboval, of medium thickness, ventricose, with a rather angular appearance at about one-fourth the length from the anterior margin; surface sculptured by about 22 subangular, smooth radiating ridges, with narrow, canel-like grooves between; each valve with three very prominent sharp teeth; margin sharply serrate. Dimensions — Long, i mm.; alt. 23 mm.; diam. 19 mm. Distinguishable by angular appearance near anterior side, and by the com- paratively small number of smooth radiating ridges. Specimens identified by Dr. Dall. Rather common in the upper San Pedro series of San Pedro, Long Beach and Los Cerritos; one specimen from the lower San Pedro series of Deadman Island. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the 140 CALIFORNIA ACADEMY OF SCIENCES. collection of Delos Arnold. Found abundantly in the Pleistocene of Twenty-sixth Street and Spanish Bight, San Diego. Living. — Gulf of California to Panama (Dall). Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Cooper; Dall; Arnold). Subgenus Cerastoderma Movch.. Shell rotund or obovate, closed; with strong ribs obsoletely granulosa or intricate or smooth; no posterior or anterior area; channels single; hinge normal. Type, Cardium edule (Linne). 73. Cardium (Cerastoderma) corbis Mariyn. Pectunculis corbis Mart., Univ. Conch., PI. XXVIII, fig. 2, p. 1784. Cardium corbis Mart., Carpenter, Brit. Assn. Rept., 1863, p. 642, ^=C. californicum Con. =C. 7milalli Co-a. {fide Gabb, Pal. Cal., Vol. II. p. 98, 1869). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 232. Keep, West Coast Shells, p. 180, fig. 153, 1892. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1093. Shell large, subtrigonal, ventricose, thick; umbones prominent, anterior to center; surface ornamented with about thirty-seven prominent, regular, squarish, close-set, radiating ridges, which are made more or less rugose by incremental ridges on their surface; near the posterior margin these ridges become more rounded and less prominent; between the ridges are equal, deep, canal-like grooves; margin crenulated; ligament short, external, prominent; each valve with one prominent cardinal tooth, and two laterals, one anterior and the other posterior; muscle impressions prominent, subequal. Dimensions.- — Long. 71 mm.; alt. 71 mm.; diam. 57 mm. Distinguishable by the regular, only slightly rugose ridges. Specimens identified by Dr. Dall. Found in the lower San Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series of Deadman Island, San Pedro, Los Cerritos and Crawfish George's. Found also in the Pleistocene of the bath-house, Santa Barbara. Living. — Kodiak to Santa Barbara; Kamtschatka (Cooper). Pleistocene. — San Francisco; Monterey; San Pedro (Cooper): San Pedro; Santa Barbara (Arnold). Subgenus Laevicardium Swainson. Shell thin, oval, closed; middle of the valves smooth or feebly radially sculptured; ends with a smooth area; hinge normal, but with the anterior laterals springing from the umbonal cavity; periostracum smooth. Type, Cnrdiuin norvegiciim (Spengler). ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 141 74. Cardium (Laevicardium) elatum Sowcrby. Plate XX. Cardium e/atum S^\'., Conch III, Vol. I, 1838. Reeve, Conch. Icon., PI. VIII, fig- 41. Valen- ciennes, Voy. Venus, PI. XVII, fig. r, 1846. Liocardium elatum Sby., Carpenter, Brit. Assn. Rept. , 1863, p. 642. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 246. Keep, West Coast Shells, p. 181, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. Lcsvicardium elatum Sby., Gabb, Pal. Cal., Vol. II, p. 99, 1869. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 11 11. Shell large, oval, oblique, elongated, equivalve, somewhat inequilateral ; surface sculptured by numerous faint, squarish, radiating ribs, and fine, wavy incremental lines; inner surface of margin corrugated ; hinge strong, with one prominent cardinal and one prominent anterior lateral tooth in each valve ; muscle-impressions distinct. Dimeyisions. — Long. 144 mm.; alt. 167 mm.; diam. 136 mm. This is the largest of the Gardiidm, and is easily recognizable by its immense size and nearly smooth surface. A tine pair of this species, described above, and figured, was found in the upper San Pedro series at the north end of the San Pedro bluflf. Another specimen was obtained by Dr. A. A. Wright and Mrs. Oldroyd in tlie upper San Pedro deposits of Los Cerritos. This species is one of the typical southern forms found in the upper San Pedro series. Living. — San Pedro to Mazatlan (Cooper). Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Gabb; Dall). 75. Cardium (Laevicardium) substriatum Conrad. Cardium substriatum Con., Jour. Phil. Acad. Sci , Vol. VII, 1837, p. 228, PI. XVII, fig. 2. Liocardium substriatum Coti , ^= cruentatum Gould, {Jide Carpenter, Brit. Assn. Rept., 1863, p. 642.) Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 246. Keep, West Coast Shells, p. 181, fig. 154, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. Lcsvicardium substriatum Con., Gabb, Pal. Cal., Vol. II, p. 99, 1869. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, page mi. Shell small, obliquely ovate, ventricose, thin ; surface smooth, except for minute incre- mental lines and nearly obsolete radiating striae ; one small sharp cardinal tooth in each valve ; two narrow elongated lateral teeth in each valve, the posterior one in the left valve not prominent ; interior of margin finely crenulated. Dimensions. — Long. 17 mm.; alt. 18 mm.; diam. 13 mm. Distinguishable by its small size and smooth surface. Specimens identified by Dr. Dall. Rare in the lower San Pedro series of Deadman Island and San Pedro, and in the upper San Pedro series of Deadman Island, San Pedro, Crawfish George's, and Los Cerritos. Found also in the Pleistocene at Twent3r-sixth Street, San Diego. Living. — Monterey to South America (Cooper). Pleistocene. — Santa Barbara; San Pedro; San Diego (Cooper): San Pedro (Arnold): San Diego (Arnold). 142 CALIFORNIA ACADEMY OF SCIENCES. Genus Protocardia Beyrich. Shell globose, with a posterior area sharply distinguished by sculpture from the rest of the surface; closed; hinge normal; no lunule or escutcheon. Type, Cardium hillaniim (Sowerby). 76. Protocardia centifilosa Carpenter. Cardiiim var. centifilosmn Cpr., Brit. Assn. Rept. 1863, p. 642. Cardium ccntifilosian Cpr., Gabb, Pal. Cal., Vol. II, p. 99, 1869. Cooper, yth Ann. Rept. Cat. St. Min., 1888, p. 232. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 189. Protocardia centifilosa CpR., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 11 13. Shell small, suboval, ventricose, thin; umbones central, prominent, only very slightly bent; surface sculptured by numerous fine, close-set, rounded, radiating ridges, which are made slightly rugose by numerous fine, incremental lines on their surface; thin, sharp teeth in each valve; pallial sinus shallow, wide; margin beautifully and sharply serrate. Ditnensiotis . — Long. 23 mm.; alt. 22.5 mm.; diam. 15 mm.. Distinguishable by tlie nearly circular outline and numerous fine, radiating ridges. Specimens identified by Dr. Dall. Not uncommon in the Pliocene of Deadman Island and Timm's Point; rare in the lower San Pedro .series of Deadman Island. Found also in the Pleistocene at bath-house and the Pliocene of Packard's Hill, Santa Barbara. Living. — Monterey to Catalina Island (Cooper). Pleistocene. — San Pedro (Cooper; Arnold): Santa Barbara (Arnold). Pliocene. — San Pedro (Arnold): San Diego well (Dall): Santa Barbara (Arnold). Pliocene. — Sunol, Alameda County (Cooper). Superfamily VENERACEA. Family XXVIT. VENERID^. Subfamily VENERIN^. Genus Tivela Linl-. Shell triangular, subequilateral, cuneiform; three to five cardinal teeth in one valve, four to six in the other; anterior lateral tooth narrow, elongated, compressed; pallial impression with a short oblique or sometimes horizontal sinus. Cyfherea is a characteristic species. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 143 77. Tivela crassatelloides Conrad. Cytherea {Trigonella) crassatelloides Con., Jour. Phil. Acad. Sci. , Vol. VII, 1837, p. 253, PI. XIX, fig. 17. Hinds, Voyage Sulpher, p. 65, PI. XXI, fig. i, 1844. Donax slidtorum Marve, Linn., Lyst. Conch., pp. 37, 40, PI. IX, fig. 7, 1823. Gray, Index. Test. Suppl., PI. II i^Donax), fig. 2, 1828. Cytherea crassatelloides Con., Hanley, Descr. Cat. Rec. Bivalve Shells, p. 106, 1843. Sowerbv, Thes. Conch., Vol. II, p. 612, PI. CXXVII, figs. 1-3. Reeve, Icon. Conch., Vol. XIV, PI. I, fig. 3, 1864. Cytherea slidtorum Gray, Hanley, Descriptive Cat. Rec. Bivalve Shells, p. 106, 1843. Trigonella crassatelloides Con., Jour. Phil. Acad. Sci., Vol. I, 1849, p. 213. Trigo/iia crassatelloides CoK., Deshayes, Cat. Conch. Coll. B. M., Part i, p. 46, 1S53. Trigonia stultorum Gray, Deshayes, Cat. Conch. Coll. B. M., Part i, p. 46, 1853. Pachydesma crassatelloides CoN., Proc. Phil. Acad. Sci., 1854, p. 121. Carpenter, Brit. Assn- Rept. 1863, p. 640; =Cytherea solidissima Phil., Gabb, Pal. Cal. Vol. II, p. 96, i86g. Cooper, 7th. Ann. Rept. Cal. St. Min., 18S8, p. 256. Keep, West Coast Shells, p. 189, fig. 162, 1892. Tivela crassatelloides CoN., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 187. Cytherea {Tivela) crassatelloides Con., Stearns, Proc. U. S. Nat. Mus., Vol. XXI, 1898, pp. 371- 378, PI. XXIII-XXV. Stearns, Nautilus, Vol. XIII, 1899, p. 73. Shell large, subequilateral, trigonal, depressed, thick; umbones subcentral, small; anterior extremity shorter and more obtusely rounded than posterior; anterior dorsal margin nearly straight slopes down obliquely from umbo ; posterior dorsal margin slightly concave in fi-ont of umbo, slope less than anterior; posterior extremity narrower than anterior; three prominent, thick, cardinal teeth in each valve, anterior lateral tooth elongated; pallial sinus short, angular. Dimensions. — Long. 80 mm.; alt. 55 mm.; diam. 30 mm. The Pleistocene specimens have a tendency toward more central umbones than do the living forms. This species is distinguishable from the Mactras by its very thick shell and heavy cardinal teeth. Specimens identified by Dr. Dall. Common in the upper San Pedro series of San Pedro, Los Cerritos, Long- Beach, Crawfi.sh George's and Deadman Island; rare in the lower San Pedro series of Deadman Island. Found also in the Pleistocene of Twenty-sixth Street and Spanish Bight, San Diego. Living. — Santa Cruz to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego; (Arnold). Genus Callista Poli. Shell oval, transverse, inequilateral; pallial sinus suboval, profound. Cytherea erycina Linn, is a characteristic species. 78. Callista newcombiana Gahb. Lioconcha ne^vcombiana Gabb, Proc. Cal. Acad. Sci., 1865, p. 189; Pal. Cal., Vol. II, p. 96, i86g. Callista newcombiana Gabb, Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 187, PI. XXIII, fig. 4. Shell thin, trigonally ventricose, polished, marked by minute concentric strize; beaks large, subcentral; anterior end prominent, narrowly rounded; posterior end a little the widest; base arcuate; 144 CALIFOKNIA ACADEMY OF SCIENCES. lunule not excavated, but bounded by an impressed line; hinjjje not strong; two small cardinal teeth; ligamental area excavated, internal. Dimensions. — Long. 38 mm.; alt. 30 mm.; diam. 10 mm.; length of lunule 12 mm. This species is distinguisliiible from C. sahdlaphana Carpenter by its promi- nent impre-sseJ liinule-bounding line, ronnded pallial sinus, and by its coloration in the living specimens. Rare in upper San Pedro series at Deadmau Island. Abundant at Twenty- sixth Street, San Diego. Living. — Monterey to Catalina Island (Cooper): San Pedro (Williamson). Pleistocene. — San Pedro (Arnold): San Diego (Coo]ier; Arnold). Pliocene. — San Diego well (Cooper). 79. Callista subdiaphana Carpenter. Plate XIII, Fig. 4. Clevie7ilia subdiaphana Cpr., Brit. Assn. Rept. 1863, p. 640; Proc. Phil. Acad. Sci., 1865, p. 56. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 235. Dall, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 185, PI. VII, figs. 5 and 6. Shell of medium size, oval, transverse, inequilateral, ventricose, rather thin; beaks small, incurved; anterior extremity quite sharply angulated about middle of shell; posterior extremity much longer and wider than anterior and very evenly rounded, projecting furthest a little below the middle; ventral margin evenly arcuate; surface sculptured by numerous fine, regular, concentric, incremental lines; neither lunule nor escutcheon, but a faint lunular circumscribing line in front of umbo; three prominent, sharp, cardinal teeth in each valve, the anterior one being narrower and longer than the other two; external ligamental groove long, narrow; pallial sinus cuneiform, rather deep. Dimensions. — Long. 43.5 mm.; alt. 34 mm.; diam. 26 mm.; umbo to anterior extremity 10 mm.; to posterior extremity 33.5 mm. This sjiecies is very close to Conrad's Dioue anr/usfiformis from the Astoria Miocene, the external characteristics of both being almost identical. Specimens identified by Dr. Dall. Rather common in the Pliocene of Deadman Island and Timm's Point. ' Cooper's " Quarternary " at San Pedro includes the Pliocene, and his specimens from San Pedro were probably from the Pliocene. The writer has never found Callista subdiaphana in the Pleistocene of San Pedro or vicinity. The specimen figured is from the Pliocene of Deadman Island, and is now in the collection of Delos Arnold. Living. — South Alaska Coast to San Francisco (Dall). Pleistocene. — San Pedro to San Diego (Cooper). Pliocene. — San Diego well (Cooper): San Pedro (Arnold). 80. Callista subdiaphana Carpenter, pedroana, var. nov. Plate XIII, Fio. 2. Shell of medium size, subelliptical, transverse, inequilateral, ventricose, rather thin; beaks small, incurved; anterior extremity evenly rounded, short; posterior extremity faintly biangular, ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 145 caused by a slight, very oblique truncation across the middle of the extremity; posterior portion of the ventral line nearly straight; interior the same as in C. siibdiaphana. Dimensio7is. — Long. 32.5 mm.; alt. 24 mm.; diam. 15 mm. This variety is very distinct from the typical G. dlapliana, being much narrower, less ventricose and smaller; and having a shorter, more rounded anterior extremity, a biangular posterior extremity, and a nearly straight ventral margin. This variety has been found only in the lower San Pedro series of Dead- man Island. Pleistocene. — San Pedro (Arnold). Subgenus Amiantis Car^^enter. Fulcra very thick and surface very concentrically rugose. Type, Cytherea callosa Conrad. 81. Callista (Amiantis) callosa Conrad. Cytherea callosa Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 252. Venus callosa Con., Sowerby, Thes. Conch., Vol, II, p. 712, PI. CXIV, figs. 44, 45. Dosinia callosa Con., Carpenter, Proc. Zool. Soc, 1856, p. 216. Amiantis callosa Con., Carpenter, Brit. Assn. Rept., 1863, p. 640. G-\bb., Pal. Cal., Vol. II, p. 96, 1869. Tryon, Syst. Conch., Vol. Ill, p. 178, 1884. ^ Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 266. Keep, West Coast Shells, p. 187, fig. 160, 1892. Cooper, Bull. No. 7, 1894, Cal. St. Min. Bureau, p. 24. Meretrix callosa Con., Fischer, Conchologie, p. 1079, 1887. Callista (Ainiantis) callbsa Con.; =Dio7U' ywbilis RvE. (^fide Dall, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 187). Shell large, suboval, inequilateral, equivalve, heavy; umbones anterior to center, prominent, recurved; anterior dorsal margin slightly concave; anterior extremity quite sharply rounded near upper margin; ventral margin evenly arcuate; posterior dorsal margin slightly arcuate; posterior extremity faintly biangular; surface sculptured by numerous prominent, flat-topped, concentric ridges, between which are interspaces equal in width to the ridges; lunule distinct, concentrically striated; hinge heavy; two prominent, strong cardinal teeth; pallial sinus wide, deep and rather pointed. Di^nensions. — Long. 66 mm.; alt. 55 mm.; diam. 34 mm.; umbo to anterior extremity 20 mm.; to posterior extremity 46 mm. Cooper (Seventh Ann. Rept. Cal. St. Min., p. 266) says that this species is like Tapes montana, described by Conrad from the "Miocene of San Buenaventura." Specimens identified by Dr. Dall. Common in the upper San Pedro series of Los Cerritos, but exceedingly rare in the same horizon of San Pedro. This species is very abundant in the Pleistocene at Spanish Bight, San Diego. Living. — Santa Barbara to Lower California (Carpenter). Pleistocene. — San Pedro (Arnold): San Diego (Arnold). ( 19 ) December 31, 1902. 14G CALIFORNIA ACADEMY OF SCIENCES. Subfamily Doainina. Genus Dosinia Scupoll. Shell orbicular, compressed, concentrically striated, pale, ligament sunk; lunule deep; hinge like Cylherea; margin even; pallial sinus deep, angular, ascending. Dosinia discus Reeve ia a characteristic species. [S. D.] Dosinia ponderosa Gray. Artemis ponderosa Gray, Analyst, Vol. VIII, 1838, p. 309. Dosinia ponderosa Gray, H. & A. Adams, Gen. Rec. Moll., Vol. II, p. 432; =Cyiherea gigantea Sby. ^fide Gabb, Pal. Gal. Vol. II, p. 97, 1869). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 239. Shell large, thick, equivalve, subcircular in outline, convex; surface sculptured by many obsolete, concentric lamellje, and fine, incremental lines; lunule deeply impressed, small, finely sculptured; beaks small, not elevated; hinge very wide and heavy, with three heavy, cardinal teeth, the posterior one in the right valve being bifid; ligament long, narrow, sunken. Dimensions. — Long. 119mm.; alt. 105 mm.; diam. 55 mm.; lunule 15 mm. Commou in the upper San Pedro series (Pleistocene) of Twenty-sixtli Street, San Diego. Living — West Mexican coast to Panama (Carpenter). Pleistocene. — San Diego (Hemjihill; Arnold). Pliocene. — Kirker's Pass, Contra Costa County; San Fernando (Cooper): Stanford University, Santa Clara County (Arnold). Genus Venus Linne. Shell thick, ovate, smooth, sulcated, or cancellated; margins minutely crenulated; cardinal teeth three in each valve; pallial sinus small, angular; ligament prominent; lunule distinct. Venus verrucosa Linne is a characteristic species. [S. B.] Venus perlaminosa Conrad. Mercenaria perlaminosa CoN., Proc. Phil. Acad. Sci., 1855, p. 267. Gabb, Pal. Cal.. Vol. II, pp. 22, 55, 94; PI. V, fig. 38; PI. XV, fig. 14; 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 250. Veyms ke7inerleyi Rye., Icon. Conch. ( Venus'), PI. XII, fig. 41 {^fide Gabb). "Shell large, thick, rounded, subquadrate, very inequilateral; beaks anterior; anterior end excavated under the beaks, rounded below; base broadly rounded; posterior end convexly truncated; cardinal margin slightly convex. Surface closely marked by numerous prominent, recurved, lamelliform concentric ribs. Lunule marked by an impressed line. Hinge robust. Pallial line strong, sinus small, oblique, acute at base; muscular scars nearly equal in size; margin minutely crenulated; the purple color between the pallial line and the base is very persistent." — [Gabb.] Found in the Pliocene at Packard's Hill, and in the Pleistocene at the bath- house, Santa Barbara. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 147 Subgenus Chione Megerle. Shell oval, triangular or subcordiform; margins finely crenulated; hinge narrow, solid, with three teeth in the right valve and two in the left, the anterior tooth longest; ligament narrow; pallial sinus shallow. Venus gnidin Bred, is a characteristic species. 82. Venus (Chione) fluctifraga Soiverby. Plate XIV, Fig. 2. Vemis fluctifraga Sby., Thes. Conch., 1842-1859. Chione fluctifraga Sbv., -\-C. callosa Sv,\.\ = Venus cortesi Slo at; = V. giddosula (Desh.) KvE. {fide Carpenter, Brit. Assn. Rept., 1863, pp. 641, 666). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 234. Keep, West Coast Shells, p. 187,1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188. Shell of medium size and thickness, suboval; surface roughened by radiating rows of squarish blocks, this condition being caused by wide concentric ridges being cut by radiating sulcations; spaces between the concentric ridges ornamented by fine, even, incremental lines; lunule of same sculpture as shell, scarcely differentiated; two prominent teeth and a rudimentary anterior one in the right valve; pallial sinus quite deep; muscle-impressions elongate-oval. Diniejisions. — Long. 25 mm.; alt. 21 mm.; diam. 15 mm. Distinguishable from others of this genus found in these beds by being more swollen, oval rather than cordiforin in shape, thinner shelled, by the " blocked " surface, and by the lunule being scarcely differentiated from the rest of the shell. Specimen identified by Dr. Dall. Rare in upper San Pedro series of San Pedro ; one specimen, a right valve, which is figured, and is now in the collection of Delos Arnold. Common in the Pleistocene at Twenty-sixth Street, San Diego. Living. — San Pedro to San Diego; Gulf of California (Cooper). Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro; San Diego (Arnold). 83. Venus (Chione) gnidia Broderip £ Sowerby. Plate XIV, Fig. 7. Verms gnidia Sby., Gen. Rec. & Fos. Shells ( Venerida:), fig. 7, 1824. Venus gnidia Brou. & Sby., Zool. Jour., Vol. IV, 1829, p. 364; Zool. Beechey's Voyage, p. 151, PI. XLI, fig. 3, 1839. Reeve, Syst. Conch., Vol. I, fig. 5, 1841. Carpenter, Brit. Assn. Rept., 1856, p. 175; 1S63, p. 561. Chione gnidia Brod. & Sby., Tryon, Syst. Conch., Vol. Ill, p. 176, PI. CXIII, fig. 14, 1884. Shell large, thick, subcordiform; surface ornamented by several prominent, palmate, concen- tric frills and numerous squarish, radiating ribs between which are canal-like sulcations of about equal width with the ribs; the ribs are sharper in outline near the beak and multiply in number both by division and intercalation as the margin is approached; near the periphery, and also on the anterior portion of the shell, the ridges become wider and less prominent, and in some cases almost obsolete; the concentric frills become widely separated in the adult shell; lunule prominent, shows fine laminae 148 CALIFORNIA ACADEMY OF SCIENCES. of growth which are most prominent when projections of the frills; hinge narrow, solid; three cardinal teeth in right valve, two in left; ligament narrow; pallial sinus much shorter than lunule; muscle-impressions distinct. Dimensio7is. — Long. 98 mm.; alt. 83 mm.; diam. 62 mm.; lunule 18 mm. This is the largest of the genus found in these deposits and is easily distinguishable by its size, prominent concentric frills and numerous radiating ribs. The specimen whose dimensions are given above had twenty-four concentric frills and about ninety radiating ribs. S^jecimens identified by Dr. Dall. Rare in the upper San Pedro series of San Pedro, whence the specimen figured came. This specimen is now in the collection of Delos Arnold. Living. — -Gulf of California to Panama (Carpenter). Pleistocene.- — San Pedro (Arnold). 84. Venus (Chione) neglecta Soiverby. Plate XIV, Fig. 3. Venus neglecta Sv.N., Thes. Conch., 1842-1849. Carpenter, Brit. Assn. Rept., 1856, p. 306. Shell of medium size and thickness, suboval; surface ornamented with quite numerous, about equidistant, undulating, concentric, low frills, and numerous unequal, rounded, radiating ridges^ which are most prominent on the middle of the shell; lunule prominent, ornamented with minute concentric and radiating sculpture; hinge and pallial sinus are as in C. succinta. Dhnensiojis. — Long. 29.5 mm.; alt. 24 mm.; diam. 13 mm ; lunule 6 mm. This species is close to C. succincta, but may be differentiated by its more oval outline, thinner shell, relatively less diameter, and less prominent but more numerous concentric frills. Specimen identified as " probably 0. neglecta " by Dr. Dall. Rare in ujjper San Pedro series of San Pedro and Los Cerritos. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Gulf of California and Central America (Carpenter). Pleistocene. — San Pedro (Arnold). 85. Venus (Chione) simillima Sowerby. Venus simillima Sbv., Thes. Conch., p. 708, PI. CLIII, figs. 17, 18, 1842-1859. Chione simillima Sbv., Carpenter, Brit. Assn. Rept., 1863, p. 641. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 234. Keep, West Coast Shells, p. 186, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188. Shell of medium size, thick, subcordiform ; surface ornamented by numerous slightly crenulated, refle.xed, concentric frills, which grow closer and closer together as the periphery is approached, and by about twenty bifurcated, radiating ridges, which are largest in the middle of the shell, becoming obsolete anteriorly and posteriorly, and increasing in number, but fading out as the periphery is approached; lunule prominent, ornamented with incremental lamina; hinge narrow; only two prominent cardinal teeth on each valve; pallial sinus very shallow; margin crenulated. Dimensions. — Long. 40 mm. ; alt. 35 mm. ; diam. 25 mm. ; lunule 9 mm. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 149 Distinguishable from others of this genus occurring in these deposits by the even, close, lattice-like sculpture. Specimens identified by Dr. Dall. Common in upper San Pedro series at San Pedro, Los Cerritos, Crawfish George's, and Deadman Island; rare in the lower San Pedro series at Deadman Island. Found also in the Pleistocene at Twent3'--sixth Street, San Diego. Living. — Monterey to Lower California (Carpenter). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego (Arnold). 86. Venus (Chione) succincta Valenciennes. Plate XIV, Fig. 1. Veiius sticcincta Val., Humb. & Bonpl., Obs. sur Zool., p. 219, PI. LXVIII, fig. i, 1833. Chione succincta Val. =C califoniiensis Brod. =C mdtalli Con. ^fide Carpenter, Brit. Assn. Rept., 1863, p. 641.) Chione succiticla Val. = Venus californica CoN. = V. nuttalli CoN. = V. laynellifera Con. (Wilkes' Exped. and Jour. Conch., 1865; not V. lamelli/era Cofi.,]onT. Phil. Acad., Vol. VII, viW\ch ^ Tapes siajninea var. ruderaia) =V. brevilineata Con. =^Chione brevilineata Con. = F. securis Shum. (yfide Gabb, Pal. Cal., Vol. II, p. 94, 1869). Cooper, 7th Ann. Rept Cal. St. Min., 1888, p. 234. Keep, West Coast Shells, p. 187, fig. 159, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188. Shell of medium size, thick, subcordiform; surface ornamented by several about equidistant, slightly reflexed, low, concentric frills and numerous rounded, radiating ridges, most prominent on the middle of the shell, which increase by intercalation and become flattened and less prominent as the periphery is approached; lunule prominent, ornamented by both incremental laminae and rounded, radiating ridges; hinge narrow; two prominent cardinal teeth in each valve; pallial sinus very shallow; margin crenulated. Dimensions. — Long. 55 mm.; alt. 50 mm.; diam. 32 mm.; lunule 13.5 mm. The specimen whose measurements are given was the largest of the specimens examined. Distinguishable by the equidistant concentric frills, low, rounded, radiating lines, and radiating lines on the lunule. Rather common in upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's and Deadman Island. Found also in the Pleistocene of Barlow's ranch, Ventura, and Twenty-sixth Street, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Santa Barbara to San Diego; Mexico; South America (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold). Pliocene. — Seven Mile Beach, San Mateo County; San Fernando (Cooper). Miocene. — Oregon; Martinez; San Pablo; Griswold's, San Benito County; Foxin's, Santa Barbara County; Santa Monica (Cooper). Superfamily TAPETIN.E. Genus Tapes Megerle. Shell oblong, umbones anterior; margins smooth; teeth three in each valve, more or less bifid; pallial sinus deep, rounded. Ihpes litterata Linne is a characteristic species. 150 CALIFORNIA ACADEMY OF SCIENCES. 87. Tapes laciniata Carpenter. Plate XIV, Fig. 5. Ta/>es laciJiiata Cpr., Brit. Assn. Rept., 1863, p. 641; Jour, de Conch., Vol. XII, 1865, p. 136 Keep, West Coast Shells, p. 186, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188. Shell large, oval, swollen, thick, but brittle; surface net-like, caused by prominent, thick rounded, concentric frills, and numerous rounded, radiating ridges; margin smooth; hinge and interior parts as in T. staminea. Dimensions. — Long. 80 mm.; alt. 6S mm.; diam. 56 mm. Resemble.? T. staminea in otitliiie, but is much larger, heavier, ami more brittle, and has a much more decided cancellate sculpture. Rare in upper San Pedro series at San Pedro, but rather common at Los Cerritos in the same horizon. The specimen figured is from the upper San Pedro series at Los Cerritos, and is now in the collection of Delos Arnold. Living. — Monterey to San Diego (Carpenter). Pleistocene. — San Pedro (Arnold). 88. Tapes staminea Conrad Plate XIV, Fig. 4. Venus slaminea CoN., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 250, PI. XIX, fig. 15, Tapes staminea Con., Carpenter, Brit. Assn. Rept., 1S63, p. 641; ^ V. lamelli/era Con., (Jour. Phil. Acad., Vol. VII, 1837; not of Wilkes' Exped.); = T. diverstim Co'N.; =T. /ineafi/m Con.; =Ve7ius rigida Gld. (/(/cGabr, Pal. Cal., Vol. II, p. 97, 1869). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 266. K5EP, West Coast Shells, p. 185, fig. 158, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188. Shell of medium size and thickness, suboval, convex; surface sculptured with numerous, crowd- ed, rounded, radiating ridges, and concentric lines, which are most prominent on anterior end; nolunule; margin sometimes crenulated; hinge narrow; ligament narrow, long; three teeth in each valve; posterior two in right valve and middle one in left valve bifid; pallial sinus long, rounded; muscle- impressions not sunken. Dimensions. — Long. 50 mm.; alt. 42.5 mm.; diam. 30 mm. This is a variable species, the shape of the shell and the sculpture varying in different individuals. The form above described is the most common in tlie San Pedro beds. Specimens identified by Dr. Dall. Rare in the lower San Pedro series at Deadman Island and San Pedro; common in the upper San Pedro series at Deadman Island, San Pedro, Los Cerritos, Crawfi.sh George's and Long Beach. Tbe specimen figured is from the upper San Pedro series of San Pedro and is now in tbe collection of Delos Arnold. Found in the Pliocene at Pacific Beach and Russ School; and in the Pleistocene at Twenty- sixth Street and Spanish Bight, San Diego. Living. — Straits of Fuca to Lower California (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego (Arnold). ARNOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDRO. 151 Pliocene. — Santa Rosa; Twelve Mile House, San Mateo County; Kirker's Pass, Contra Costa County; Monterey; San Fernando (Cooper) ; San Diego (Arnold). Miocene. — West of San Jose; Foxin's, Santa Barbara County (Cooper). 89. Tapes tenerrima Carpenter. Plate XIV, Fi<;. 6. Tapes lenerrima Cpr., Proc. Zool. Soc, 1856, p. 200; (jun.) ^=Vcnus rigida Gld., pars, {fide Carpenter, Brit. Assn. Rept., 1863, p. 641.) Gabb, Pal. Cal, Vol. II, p. 97, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 267. Keep, West Coast Shells, P- 157. fig, 136, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188. Shell large and thin, oval, convex; surface sculptured by numerous low, sharp, concentric frills, and numerous tine, rounded, crowded, radiating lines, these latter lines being almost obsolete in some specimens; margin smooth, hinge long and narrow; three teeth in each valve, the anterior two in the right valve and the middle one in the left valve prominently bifid; pallial sinus very deep and rounded; no lunule. Dimensions. — Long. 86 mm.; alt. 63.5 mm.; diam. 34 mm. This is the largest and finest Tapnn found in these deposits, and is easily distinguishable by its largo, thin, shallow shell and regular, oval outline. Specimens identified by Dr. Dall. Rather rare in the upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's and Deadman Island. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Found also in the Pleistocene at Barlow's ranch, Ventura, and at Spanish Bight, San Diego. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego; Ventura (Arnold). Pliocene. — Santa Barbara (Cooper). Genus Saxidomus Conrad. Shell transversely oval, inequilateral, solid, ventricose; without lunule; umbones tumid; teeth three or four, inequal, narrow, the central bifid; ligament very thick, elongated; muscular impressions oval or rouuded, nearly equal; pallial sinus large, elongated, horizontal. Type, Saxidomus nuttallii (Con.). 90. Saxidomus aratus Gould. Saxidomus araius Gld., Otia Conch., p. 168, 1862. Carpenter, Brit. Assn. Rept., 1863, p. 641. Keep, West Coast Shells, p. 183, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188. Tapes gracilis Gld., Pac. R. R. Rept, Vol. V., p. 333, PI. XIX, fig. 20, 1853. Saxidomus gracilis, Gld., = Venus maxima Phil, (fide Gabb, Pal. Cal., Vol. II, 1869, p. 98). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 263. 152 CALIFORNIA ACADEMY OF SCIENCES. Shell large, transversely elliptical, equivalve, inequilateral, convex, thick; umbones turned, anterior to middle; anterior end evenly rounded; posterior end much more produced, having a slight tendency toward biangulation; surface sculptured with strong, elevated concentric lines, which in the adult often have the prominence of concentric lamina; ligamental area external, wide, long, strong; cardinal teeth four, anterior one long and narrow; pallial sinus long, rather narrow, rounded extremity near middle of shell and impressed against the posterior adductor scar. Dimens/o/is. -^hong. 89 mm.; alt. 62 mm.; diam. 44 mm.; umbo to anterior extremity 30 mm. ; to posterior extremity 59 mm. Specimens identified by Dr. Dall. Rare in the lower San Pedro series of Deadman Island; common in the upper San Pedro series at Deadman Island, Crawfish George's, Los Cerritos and San Pedro. Found also in the Pleistocene at Barlow's ranch, Ventura, and at Twenty-sixth Street, San Diego. Living. — Baulines Bay to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; Blakeley, near Seattle, Washington (Arnold) : San Diego; Ventura (Arnold). Pliocene. — Kirker's Pass, Contra Costa County; Twelve Mile House, San Mateo County; Santa Barbara, San Fernando (Cooper). Miocene. — Martinez; Walnut Creek, Contra Costa County; Santa Cruz; Santa Inez, Santa Barbara County; Santa Monica (Coojier). Subfamily GEMMIN.E. Genus Psephis Carpenter. Shell thin, rounded or quadrangular, somewhat inflated; pallial sinus small; three elongated, thin, cardinal teeth in each valve. Psephis lordi (Baird) is a characteristic species. 91. Psephis salmonea Carpenter. Psephis salmonea CpR., Brit. Assn. Rept., 1863, p. 641. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 261. Shell very small, ovate trigonal, inequilateral; posterior end evenly rounded; posterior dorsal margin rounded; in other ways resembles P. ianlilla. Dimensions. — Long. 5 mm.; alt. 4 mm.; diam. 2.5 mm. Distinguishable from P. tantilla by smaller size and less trigonal outline. Specimens examined showed no coloration. Rare in the lower San Pedro series at Deadman Island and San Pedro. Found also in the Pliocene at Packard's Hill, and in the Pleistocene at the bath- house, Santa Barbara. Living. — Catalina Island (Cooper; Arnold): 10 fathoms (Arnold, 1901). Pleistocene. — Santa Barbara (Cooper): San Pedro; Santa Barbara (Arnold). Pliocene. — Santa Barbara (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 153 92. Psephis tantilla Gould. Plate XIII, Fig. 5. Venus tantillus Gld., Bost. Jour. Nat. Hist., Vol. VI, 1853, P- 906, PI. XV, fig. 10. TrigoJiJa ianiilla Gld., Carpenter, Proc. Zool. Soc, 1856, p. 201. Psephis tantilla Q\.v>., Carpenter, Brit. Assn. Rept., 1S63, p. 640; =Venus rysonia Gabb {Jide Gabb. Pal. Cal., Vol. II, p. 96, i86g). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 261. Keep, West Coast Shells, p. 186, 1892. Williamson, Proc. U.S. Nat. Mus., Vol. XV, 1S92, p. 188. Shell small, ovate-trigonal, inequilateral; beaks acute, slightly anterior to center; surface smooth or faintly waved with distant, concentric furrows; the dorsal margins are nearly straight, and meet at the apex in a right angle, but the posterior side is a fourth longer than the anterior; the anterior basal angle is well rounded, while the posterior is acute; basal margin gently curved; hinge area short, wide; three prominent, elongated cardinal teeth in each valve. Dimensions. — Long. 10 mm.; alt. 8 mm.; diam. 4.9 mm. Somewhat re.sembles a very small Tivela crassaielloides. Some show original purple spot on posterior end. Specimens identified by Dr. Dall. Rather common in the lower San Pedro series at Deadraan Island and San Pedro; rarer in the upper San Pedro series at Deadman Island, Los Cerritos, and San Pedro. The specimen fii^ured is from the lower San Pedro series at Deadman Island and is now in the collection of Delos Arnold. Living. — Straits of Fuca to Catalina Island (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). Family XXVIII. COOPERELLID.E. Genus Cooperella Carpenter. Shell small, thin, smooth, or concentrically striate or undulate, equivalve, nearly equilateral, with entire margins; ligament long; resilium short; hinge plate narrow, carrying two right and three left subumbonal, divaricating, short cardinal teeth; laterals none; pallial line narrow, with an ample sinus. Type, CEdalia suhdiaphnna (Carpenter). 93. Cooperella subdiaphana Carpenter. Plate XIII, Fig. ]. CEdalia subdiaphana Cpr., Brit. Assn. Rept., 1863, p. 639; Jour, de Conch., Vol. XII, 1865, p. 134. QLdali7ia subdiaphana Cpr., Proc. Cal. Acad. Sci., Vol. Ill, 1866, p, 208. Cooperella subdiaphana Cpr., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1062. Shell small, subquadrangular, subequilateral, convex, very thin and fragile; posterior extremity evenly rounded; anterior extremity rounded near base; surface smooth except for incremental lines; beaks slightly raised, sharp, prominent; two narrow, tall, sharp, bifid teeth in left valve, three in right; pallial sinus very large. Dimensions. — Long. 12 mm.; alt. 9 mm.; diam. 6 mm. ( 20 ) January 8, 1903. 154 CALIFORNIA ACADEMY OF SCIENCES. Externally this species mucli resembles a Kellia, but may be distinguished by the pallial sinus and hinge teeth. Specimens identified by Dr. Dall. Two left valves from lower San Pedro series of Deadman Island, one of which is figured, and is now in the collection of Delos Arnold. Rather common in the Pleistocene at Spanish Bight, San Diego. Living. — Vancouver Island to Todos Santos Bay (Dall). Pleistocene. — Sau Pedro (Dall; Arnold): San Diego (Arnold). Family XXIX. PETRICOLID.E. Geuus Petricola Lamarck. Shell oval or elongated, thin, tumid, anterior side short; hinge with generally three teeth in each valve, the external often obsolete; pallial sinus deep. Type, Venus lapicida (Chemn.). Section Petricola Larnarch a. s. Shell ovate, with a short or moderately wide pallial sinus, the radial sculpture more or less divaricate or zigzag. Type, Petricola lapicida (Gmel.). 94. Petricola carditoides Conrad. Saxicava carditoides CoN., Jour. Acad. Nat. Sci. Phil., Vol. VII, 1837, p. 255, PI. XX, fig. 8. Petricola carditoides Con. , Jour. Acad. Nat. Sci. Phil., 1849, p. 213. Carpenter, Proc. Zool. Soc, 1856, p. 214; =/". califorjiica CoN. ^P. cylindracea Desh. =/*. arcuata Desh. ^P. gibba MiDD. (7?^^ Carpenter, Brit. Assn. Rept., 1863, p. 641). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 258. Keep, West Coast Shells, p. 183, 1892. William- son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 189. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p: 835; Part 5, 1900, p. 1059. Shell of medium size and variable outline, generally oblong-oval, conve.x, thick; surface ornamented with fine, concentric, incremental lines, which sometimes form irregular ridges, and by fine, wavy, radiating lines; hinge-area prominent; three cardinal teeth in each valve, the anterior one smallest; margin smooth. Dimensio7ts. — Long. 28 mm.; alt. 25 mm.; diam. 16 mm. A variable form which is recognized, however, by its sculpture, prominent teeth and thick shell. Often found in holes in the pebbles and boulders comprising the conglomerate in this formation. Specimens identified by Dr. Dall. Not uncommon in the lower San Pedro series at Deadman Island; and in the upper San Pedro series at Deadman Island, Los Cerritos, Crawfish George's, and San Pedro. Found also in the Pleistocene at Spanish Bight, San Diego. Living. — Sitka to San Diego (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 155 Section Rupellaria Fleurian. Shell inflated and rounded in front, attenuated and more compressed behind; sculpture chiefly radial ; stronger anteriorly. Type, Petricola lithophaga (Retzius). 95. Petricola (Rupellaria) lamellifera Conrad. Veyms lamellifera Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 257, PI. XIX, fig. 19. Veneriipis cordieri v^r. B, Desh., B. M. Catal. Ven., p. 191, No. i. Petricola cordieri D^sn., Rev. Zool. Soc. Cur., 1839, p. 358; Mag. Zool., PI. XVIII. Rtipellaria lamellifera Con., Carpenter, Proc. Zool. Soc, 1856, p. 214. Carpenter, Brit. Assn. Rept., 1863, p. 641. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 262. Keep, West Coast Shells, p. 1S3, fig. 156, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 184. Shell of medium size, convex, equivalve, inequilateral, thick; beaks anterior to middle, marginal, not much elevated, turned slightly forward ; anterior extremity evenly rounded ; posterior extremity widely truncated; surface sculptured by ten or twelve lamelliform, concentric, slightly reflected ribs, and rather faint radiating sulcations; lunule indistinct, sculptured; ligament rather short; hinge strong, with two bifid and one single tooth in each valve; pallial sinus deep, narrow, pointed; muscle-impressions distinct, oval. Dimensions. — Long. 26 mm.; alt. 21.5 mm.; diam. 16 mm. This species resembles Petricola carditoides, but is distinguishable by the prominent concentric lamellar frills. Like P. carditoides this shell bores in the rocks; and all of the specimens obtained were broken from the shale pebbles in the upper San Pedro gravels of Deadman Island. Living. — Farallon Islands to San Diego (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). Section Petricolaria Stoliczka. Shell elongated, pholadiform, thin; hinge-teeth protracted, slender; pallial sinus deep. Type, Petricola pholadiformis (Lane). 96. Petricola (Petricolaria) denticulata Sowerby. Petricola detiiiculata Sby., Thes. Conchyliorum (?). Petricola pedroana CoN., Pac. R. R. Rept., Vol. V, p. 324, PI. Ill, fig. 24, 1856. Gabb, Pal. Cal., Vol. II, p. 119, 1869. Petricola denticulata Sby., Carpenter, Brit. Assn. Rept., 1856, pp. 244, 297. Cypricardia pedroana Con., Cooper, Bull. No. 4, Cal. St. Min. Bureau, 1894, p. 25. Shell small, elongate-oval, convex, thin; surface sculptured by fine, concentric, incremental lines, and numerous, undulating, radiating ridges, which are most prominent on the anterior portion of the shell; anterior end short and rounded; teeth small; pallial sinus deepi Dimetisiotis. — Long. 20 mm.; alt. X2 mm.; diam. 10 mm. 156 CALIFORNIA ACADEMY OF SCIENCES. Distinguishable from P. carditoides by its smaller size, narrower form, thinner shell, and coarser sculpture. Specimens of this same species in the State Museum collection at the University of California, Berkeley, are labeled P. cognata Adams. Specimens identified by Dr. Dall. Rare in the lower San Pedro series at Deadman Island, and the upper San Pedro series at Los Cerritos and San Pedro. Living. — Mazatlan to Peru (Carpenter). Pleistocene. — San Pedro (Arnold; Blake.) Pliocene (?). — Los Angeles City (Williamson). 97. Petricola (Petricolaria) cognata C. B. Adams. Pelrkola cognala C. B. Ads., Cat. Panama Shells; Ann. N. Y. Lye. Nat. Hist., Vol. V, 1852, p. 510. Cpr., Brit. Assn. Rept., 1856, p. 363; Proc. Zool. Soc, 1863, p. 367. Shell of medium size, much elongated, transverse, conve.x, thin, equivalve; beaks small, near anterior e.xtremity, turned forward, slightly elevated; anterior extremity short, evenly, pointedly rounded; posterior extremity long, evenly, pointedly rounded; surface of shell, anterior to a line running obliquely backwards from the beaks, sculptured by ten or eleven prominent, narrow, squamosely spined, radiating ridges; surface posterior to this line ornamented by finer radiating lines; rather prominent incremental lines over the whole surface; hinge of left valve consists of a curved, saddle-shaped process of two teeth, one of which is bifid; hinge of right valve smaller and straighter with less prominent division of teeth. Dimensions. — Long. 36 mm.; alt. 10.5 mm.; diam. 10 mm.; beaks to anterior extremity 6 mm.; to posterior extremity 30 mm. The line of demarkation between the fine and prominent radiating sculpture in this species is not marked as in the Plioladidre. Distinguishable from P. denticnlafa by more prominent sculpture anteriorly, longer shell, more prominent hinge-teeth and more anterior beaks. P. cognata is close to the Atlantic P, plioladiformis. Some authorities, notably Carpenter, unite the two forms. Rare in the upper San Pedro series at the lumber yard at San Pedro and at Deadman Island. Living. — San Pedro to Panama (Dall, m.ss.). Pleistocene. — San Pedro (Arnold). Superfamily TELLINACEA. Family XXX. TELLINID^. Genus Tellina Linne. Subgenus Mcerella Fiiichei-. Shell small, compressed, hardly folded, acute behind, rounded in front, with feeble, concentric sculpture; left laterals obsolete; no interior radii; the sinus long, coalescent with the pailial line below. ^ Type, Pellina donncina (Linnr). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 157 98. Tellina (Mcerella) salmonea Carpenter. Plate XIII, Fic. 7. Mtrr a salmonea Qvsi., Brit. Assn. Rept., 1863, p. 639; Ann. & Mag. Nat. Hist., 3id Ser., Vol. IV, 1864, p. 423. Keep, West Coast Shells, p. 196, 1892. Shell small, suboval, convex, equivalve, inequilateral, thin; umbones anterior to center, small, sharp; anterior extremity short, rounded; posterior dorsal margin straight; posterior extremity acutely rounded; ventral margin evenly arcuate; surface glossy, ornamented with fine, concentric, incremental lines, and obsolete radiating scratches; cardinal tooth small, bifid; no lateral teeth; pallial sinus long, broad; one faint, internal, submarginal, posterior, radiating ridge. Dimensions. — Long. 11 mm.; alt. 8 mm.; diam 4.2 mm.; umbo to anterior extremity 3 mm.; to posterior extremity 8 mm. Resembles Bonax, but is mucb thinner, more evenly rounded anteriorly, has no lateral teeth, and is not crenulated on the interior of the margin. Specimen identified by Dr. Dall. Not uncommon in the lower San Pedro series at Deadman Island, whence the specimen figured came. This specimen is now in the collection of Delos Arnold. Living. — Vancouver to Monterey (Carpenter). Pleistocene. — San Pedro (Arnold). Subgenus Angulus Megevle. Shells elongated, generally small, compressed, with the posterior end angularly pointed and not twisted; the surface smooth or with fine concentric sculpture; nymphs short and prominent, the ligament short; hinge with a single adjacent lateral well developed in the right valve anteriorly; internally a thickened ray passes from the umbo just behind the anterior adductor scars, and one or two narrower similar rays in front of the posterior adductors; sinus largely coalescent with the pallial line below. Type, Tellina lanceolata Linnc'. 99. Tellina (Angulus) button! Dull. Plate XVI, Figs. 1 and 2. Tellina (Oudardia) buttoni Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1036, PI. XLVII, fig. 18. Angtilus modeslus of California collectors (not of Carpenter). Tellina (Angulus) var. obtusus Cpr. (noi Tellina obtusa Sowerby.) f Tellina pedroa7ia Con., Pac. R. R. Rept., Vol. V, p. 323, PI. Ill, fig. 17, 1855. ? Macoma pedroana Con., Gabb, Pal. Cal., Vol II, pp. 94, 124, 1S69. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 248. Shell small, oblong, subtriangular, compressed, thin; umbones slightly posterior to center; anterior dorsal margin evenly arcuate; anterior extremity quite acutely rounded, produced furthest near base; ventral line subrectilinear; posterior extremity cuneiform, abruptly truncated at end near base; surface sculptured by fine, concentric, incremental lines; one prominent cardinal tooth in each valve; one sharp, anterior lateral tooth in right valve; pallial sinus large, does not quite reach to anterior muscle-impression; anterior, radiating callus passes from umbo just posterior to the anterior muscle-impression. Dimensions. — Long. iS mm.; alt. 10.5 mm.; diam. 4 mm.; umbo to anterior extremity II mm.; to posterior extremity 7 mm. 158 CALIFORNIA ACADEMY OF SCIENCES. A note accompanying one of these specimens says, "Tellina striata Hanley. This specimen was identified by Dr. Dall." Upon further examination Dr. Dall pronounced them to be Anguhis buttoni. Found in lower Ban Pedro series of Deadman Lsland and San Pedro bluffs; and in the upper San Pedro series of Deadman Island, San Pedro, Crawfish George's, and Los Cerritos. Found also in the Pleistocene at Barlow's ranch, Ventura. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — West Coast. Pleistocene. — San Pedro; Ventura (Arnold). 100. Tellina (Angulus) bodegensis Hinds. Plate XV, Fig. 8. Tellina bodege7isis Hds., Voy. Sulphur, p. 67, PI. XXI, fig. 2, 1844. Carpenter, Brit. Assn. Rept., 1863, p. 639; =7! emacerata Con. {^fide Gabb, Pal. Cal., Vol. II, p. 92, 1869). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 267. Keep, West Coast Shells, p. 197, fig. 169, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185. Dall, Trans. Wagner Inst. Sci. , Vol. Ill, Part 5, 1900, p. 1029. Shell of medium size, elongated, narrow-ovate, rather thick; umbones posterior to center and pointing posteriorly; anterior portion of shell evenly rounded, the dorsal and ventral lines being nearly parallel; posterior dorsal margin depressed back of umbo, running off quite obliquely to a line which truncates the posterior end near the base; basal posterior angle nearly a right angle; basal line nearly straight; a prominent bifid cardinal tooth on each valve; pallial sinus long and narrow; generally thickened anteriorly. Dimeyisions. — Long. 48 mm.; alt. 25 mm.; diam. 12 mm.; umbo to anterior extremity 27 mm.; to posterior extremity 21 mm. Specimen identified by Dr. Dall. Common in the upper San Pedro series at San Pedro, Los Cerritos, Crawfish George's, Deadman Island, and Long Beach; rarer in the lower San Pedro series at Deadman Island and San Pedro. Found also in the Pleistocene at Spanish Bight, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Straits of Fuca to San Diego; Japan (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego (Arnold). Miocene. — Oregon; Walnut Creek, Contra Costa County (Cooper). loi. Tellina (Angulus) idae Dall. Plate XV, Fig. 7. Tellina idaD\-L\., Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 183, PI. VI., fig. 3; PI. VII, figs. I, 4. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185. Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 32. Tellinella, Cooper, No. 63, Geol. Cat., 1867. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 159 Shell of medium size, ovate-triangular, moderately elongate, compressed, thin; beaks sub- central, small, pointed, prominent; anterior extremity evenly rounded; posterior dorsal slope steeper, rectilinear, obliquely truncate at its termination; ventral margin moderately incurved at flexure, which is narrow, but well marked, and extends out into a prominent beak at the extremity of the shell; a prominent, narrow, submarginal, flexural ridge extends from beak to posterior extremity; surface sculptured with numerous, regular, sharp, elevated, concentric, incremental lines; hinge area broad and strong; one prominent cardinal tooth in each valve, which is bifid in right valve; one anterior lateral in right valve; ligamental area prominent, long; pallial sinus very large, extending nearly to anterior adductor scar. Dimensions. — Long. 62 mm.; alt. 37 mm.; diam. 10 mm. Distinguishable from T. bodegensis by larger, broader shell, more central, less curved beaks, much more prominent flexural ridge, posterior beak and incurved base line, much stronger, broader hinge, and much larger pallial sinus. Distinguishable from 7\ rubescens by more extended, beaked posterior extremity, flexural ridge, straight beaks, and much stronger hinge, especially in the ligamental area. Speci- mens identified by Dr. Dall. One valve found in the upper San Pedro series at Los Cerritos, which is figured herewith, is now in the collection of Delos Arnold. Living. — Catalina Island, 16 to 38 fathoms, young (Dall): San Pedro Bay; Long Beach (Shephard). Pleistocene. — San Pedro (Arnold). 102. Tellina (Angulus) rubescens Hanley. Plate XV, Fig. 9. Tellina rubescens Hanl., Carpenter, Brit. Assn. Rept., 1856, p. 302. Shell of medium size, ovate-triangular, compressed, thin; beaks posterior, small, sharp, turned toward the rear; anterior dorsal margin evenly but slightly arcuate to near extremity, where it turns off quite abruptly, giving an evenly rounded end, which is most produced below the middle; posterior dorsal slope steeper, rectilinear; posterior extremity truncated, with a rounded right angle at base; basal margin nearly rectilinear from posterior angle to within one-third length of shell from anterior end; a prominent angular ridge extends from beak to posterior basal angle; surface sculp- tured by regular alternating concentric bands and distinct sulcations; sculpture less regular posterior to angular ridge; hinge-area small; right valve with two cardinal teeth, posterior one bifid; one posterior lateral tooth at lower end of ligamental area in right valve; pallial sinus large, arcuate upwards near middle and extending nearly to anterior adductor scar. Dimensions. — Long. 43 mm.; alt. 26 mm.; diam. 10 mm.; beak to anterior extremity 23 mm.; to posterior extremity 20 mm. Distinguishable from 2\ bodegensis by mucli broader shell, less oblique trunca- tions, greater convexity, more regular and coarser sculpture, stronger hinge, posterior lateral tooth, and much larger pallial sinus, which extends ahnost to anterior adduc- tor. Distinguishable from 2\ idre by less produced and unflexed posterior portion, basal posterior angle, and rectilinear ventral margin, weaker hinge, and posteriorly bent beaks. This species seems to lie between 2\ idoB and ?'. bodegensis in many respects, having the large sinus of the one and the general, though much broader, outline of the other. Specimen identified by Dr. Dall. 160 GALIFOKNIA ACADEMY OF SCIENCES. Rare in upper San Pedro series of San Pedro; one perfect right valve, which is figured, is now in the collection of Delos Arnold. Living. — Pananaa; Central America (Carpenter). Pleistocene. — San Pedro (Arnold). Genus Metis H. <£• A. Adams. Shell slightly inequivalve, suborbicular, compressed; valve sillonated; posterior flexuosity submedian; no lateral teeth. Tellina meyeri Phil, is a characteristic species. 103. Metis alta Conrad. Tellina alia Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 258; (not T. alia Con., Foss. Tert. Form., Vol. I, No. 4, p. 41, 1833. Hanley, Thes. Conch., Vol. I, p. 332, PL LXII, fig. 200, 1847. Lutricola alia Con., Carpenter, Brit. Assn. Rept., 1863, p. 639; =Arcopag7a medialis Con. (^fide Gabb, Pal. Cal., Vol. II, p. 92, 1S69), Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 247. Keep, West Coast Shells, p. 197, 1892. Williamson, Proc. U.S. Nat. Mus., Vol. XV, 1892, p. 186. Alelis alia Con., ^ Scrobicularia biangiilata Cpr. {,fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, igoo, p. 1044). Shell large, suboval, approaching to subcircular, ventricose, of medium thickness; beaks central; anterior extremity obtusely rounded ; posterior side of the deeper valve biangulated; the opposite valve with an angular groove; surface sculptured by numerous prominent lines of growth and by numerous minute, radiating lines; cartilage-pit more vertical than oblique; muscle- impressions large. Dimensions. — Long. 75 mm.; alt. 65 mm.; diam. 40 mm. Resembles a large, rounded, ventricose Macoma. Specimens identified by Dr. Dall. Common in upper San Pedro series of San Pedro, and exceedingly so in the Pleistocene of Los Cerritos, where they occur in beautifully preserved pains. A few specimens found in the upper San Pedro series at Deadman Island and Crawfish George's; and in the lower San Pedro series at Deadman Island. Found in the Pliocene at Pacific Beach, and in the Pleistocene at Spanish Bight, San Diego. Living. — Santa Barbara to San Diego (Cooper). Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Arnold). Pliocene. — Santa Barbara (Cooper): San Fernando (Cooper; Arnold): Sau Diego (Arnold). Miocene. — Monterey; El Toro Ranch, Monterey County (Cooper). Genus Macoma Leach. Shell without lateral teeth, usually subtrigonal and with a marked posterior flexure; the surface feebly sculptured concentrically, or smooth; the siphons naked. Ty[)e, J\L tenera Leach. ARNOLD— THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO. 161 Subgenus Macoma s. s. Shell subtrigonal, the periostracum conspicuous; usually colorless, or, if colored, without color pattern; flexure well marked; the pallial sinus coalescent with the pallial line below, and often discrepant in the two valves; inhabiting the cooler seas, and especially boreal waters. 104. Macoma calcarea Gmelin. Plate XVI, Fig. 2. Tellina calcarea, teste ovala, etc., Chem., Conch. Cab., Vol. VI, p. 140, Pi. XIII, fig. 136, 1782. Tellina calcarea, Gmelin, Syst. Nat., Ed. VI, p. 3236, No. 38, 1792. Macoma calcarea Chem. = Sanguiiiolaria californica Con. = Tellina pedroana Con. = Tellina ienera Leach {fide Gabb, Pal. Cal., Vol. II, p. 124, 1869). Cooper, 7th Ann. Rept. Gal. St. Min., 1888, p. 248. Macoma calcarea GwEiAii. =^ Tellina lata Gmelin. = Tellina sudulosa Spenglkr. = Macoma tenera Leach = Tellina proxima (Brown) Sby. = Telli>ia sordida Covrnovy . = Sanguino- laria sordida Gld. {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900). Shell of medium size, suboval, slightly convex, inequilateral, thin; anterior end shorter than posterior, with fold running from apex to lower anterior extremity, which is biangular; anterior dorsal margin straight; anterior end evenly rounded; beaks anterior to middle, small, inconspicuous; surface sculptured by fine incremental lines; two cardinal teeth on left valve, anterior one bifid; pallial sinus large. Dimcnsio7is. — Long. 18.2 mm.; beak to anterior extremity 8.2 mm.; to posterior extremity 10 mm.; alt. 13.5 mm.; diam. 5.2 mm. This species is distinguishable from M. yoldiformis by its more prominent fold and much broader form; distinguished from others of this genus found in these deposits by having the anterior (folded and angular) end shorter than the posterior end. Specimens identified by Dr. Dall. Specimens of this species are labeled "J/. expansa " in the State Museum Collection, at the University of California, at Berkeley. Several specimens from the lower San Pedro series and Pliocene of Deadman Island. Tiie specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Arctic and boreal seas, south on Atlantic Coast to Long Island Sound, on Pacific Coast to Oregon and Northern Japan (Dall). Pleistocene. — Scandinavia; Scotland; Greenland; Siberia; Alaska (Dall) : San Pedro (Arnold). Pliocene. — San Pedro (Arnold). 105. Macoma indentata Carpenter. Plate XVI, Fig. 1. Macoma indentata Cpr., Brit. Assn. Rept., 1863, p. 639. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 248. Keep, West Coast Shells, p. 195, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1052. Shell of medium size, rather narrow, suboval, compressed, thin; umbones slightly posterior to center; anterior end long and evenly rounded; posterior dorsal line straight; ventral line near ( 21 ) January 9, 1903, 162 CALIFORNIA ACADEMY OF SCIENCES. posterior end indented, the posterior extremity being much projected and sharply rounded; fold very prominent; ligamental area short, scooped out. Diinenstons. — Long. 50 mm.; alt. 32 mm.; diam. 14 mm.; umbo to anterior exremity 28 mm. ; to posterior extremity 22 mm. Resembles M. nasitta and M. kcheiji, but is distinguishable by its smaller shell, jwstei'ior umboiies, indentation in ventral margin, more prominent fold and more prominently projected posterior extremity. Specimen identified by Dr. Dall. Rare in the upper San Pedro series at Los Cerritos and San Pedro. Found in the Pleistocene at Spanish Bight, San Diego. The specimen figured is from the upper San Pedro series at Los Cerritos, and is now in the collection of Delos Arnold. Living. — Monterey to San Diego (Cooper). Pleistocene. — San Pedro (Arnold): San Diego (Cooper; Arnold). Miocene. — El Toro Ranch, Monterey County; Griswold's, San Benito County (Cooper). 106. Macoma inquinata Dcshaycs. Plate XVI, Fu:. i. Tellina inquinata Desh., Proc. Zoo). Soc, 1854, p. 357. Macoma inquinata Desh., Carpenter, Brit. Assn. Rept., 1863, p. 689. Gabb, Pal. Cal., Vol. II, p. 93, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 248. Keep, West Coast Shells, p. 195, 1892. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1053. Shell of medium size, suboval, convex, thin, equivalve; umbones subcentral ; anterior end dilated, rather prominently so in front of umbo of right valve; posterior end evenly arcuate from umbo and acutely rounded at posterior end about half way between dorsal and ventral margins ; ligament of medium length, not prominent; two small cardinal teeth in each valve; pallial sinus does not reach anterior muscle-impression in the left valve. Di?ne>isio7ts. — Long. 35 mm.; alt. 27 mm.; diam. 15 mm.; umbo to anterior extremity 16 mm.; to posterior extremity 19 mm. Distinguishable by medium size, short, equally convex valves, very faint or obsolete fold; evenly, acutely rounded, rather than truncated, posterior extremity, and disconnection of pallial sinus and anterior muscle-impression. Specimen identi- fied by Dr. Dall. Not uncommon in the Pliocene at Deadman Island, the lower San Pedro series at Deadman Island, and the upper San Pedro series at Deadmnn Island, San Pedro, Los Cerritos, and Crawfish George's. Found also in the Pleistocene at Twenty-sixtli Street, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Alaska to San Diego (Cooper). Pleistocene. — Monterey to San Diego (Cooper): San Pedro; San Diego (Arnold). Pliocene. — Twelve Mile House; San Fernando (Cooper). AENOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 163 107. Macoma nasuta Conrad. Platk XVI, Fig. .S. Tellina nasuta Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 258. Macoma nasiUa Con. = y)/ tersa Gld., {fide Carpenter, Brit. Assn. Rept., 1863, p. 639). Gabb, Pal. Cal., Vol. II, p. 93, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 248. Keep, West Coast Shells, p. 194, fig. 165, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, P- 1053- Shell of medium size, ovate, compressed, thin; anterior side dilated; posterior side cunei- form, extremity truncated much above the line of the base; posterior dorsal margin straight to angle where it joins line of truncation ; fold carinated on the right valve ; umbones slightly anterior to center, slightly prominent; two prominent narrow cardinal teeth in each valve; no laterals; ligament external, long, straight, narrow; pallial sinus large, expanding interiorly, that of the left valve joining anterior muscle-impression at its lower posterior angle. Dimensions.— "Long. 76 mm.; alt. 54 mm.; diam. 23 mm.; umbo to anterior end 31 mm.; to posterior end 45 mm . Distinguishable frora M. secta by smaller size, less convex valves, less alti- tude, longer, straight posterior margin, and longer, less prominent ligaraental callus; frora M.inquinata by larger, longer shell, less convex valves, less relative altitude, straight dorsal margin with truncation posteriorly, and by less central umbones; from M. yoldiformis by more cuneiform posterior extremity, long, straight posterior dorsal margin, and by having the beaks anterior to center rather than posterior; frora M. identata by beaks being more anterior, being broader, and by lacking the promi- nent folds, indentation of ventral margin, and prominent projection of posterior extremity; from M. kelseyi, which closely resembles it, by broader shell, and more oblique truncation of posterior extremity. Specimens identified by Dr. Dall. Rather common in the lower San Pedro series at Deadraan Island and San Pedro, and the upper San Pedro series at Los Cerritos, Long Beach, Crawfish George's, Deadman Island, and San Pedro. The upper San Pedro strata afford larger specimens, as a rule, than those found in the lower San Pedro. Found also in the Pliocene at Pacific Beach, and in the Pleistocene at Spanish Bight and Pacific Beach, Sau Diego, and in the Pleistocene at Barlow's ranch, and the old ditch, Ventura. The specimen figured is frora the upper San Pedro series at San Pedro, and is now in the collection of Delo^ Arnold. Living. — Alaska to San Diego; Kamtschatka (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego; Ventura (Arnold). Pliocene. — Eagle Prairie and Danger Creek, Humboldt County; Santa Rosa; San Fernando (Cooper): San Diego (Arnold). Miocene. — Sunol, Alameda County; Foxin's, Santa Barbara County (Cooper). 164 CALIFORNIA ACADEMY OF SCIENCES. io8. Macoma nasuta Conrad var. kelseyi Ball. Mdcoma kelseyi Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1052, PI. XLIX, fig. 7. Shell of medium size, elongate-ovate, compressed, thin; posterior extremity cuneiform, obliquely truncated much above ventral margin; umbones nearly central; other characteristics same as in M. 7iasuta. Dimensions. — Long. 70 mm.; alt. 45 mm.; diam. 18 mm.; umbo to anterior end 31 mm.; to posterior end 39 mm. Distinguishable from other species by same characteristics that distinguish M. nasuta; distinguished from M. naauta by narrower, Hatter shell, and more oblique truncation of posterior end. Specimens identified by Dr. Dall. Rare in the upper San Pedro series at San Pedro and Los Cerritos. Found also in the Pleistocene at Twenty-sixth Street, San Diego. Living. — San Diego and south (Dall). Pleistocene. — San Pedro; San Diego (Arnold). 109. Macoma secta Conrad. Plate XVI, Fig. 5. Tellina secta Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 257. Hanley, Thes. Conch., p. 337, PI. LXV, figs. 245, 248, 1847. Macoma sec/a Con., Carpenter, Brit. Assn. Rept., 1863, p. 639. H. & A. Adams, Gen. Rec. Moll., p. 401, 1858. = Telli?ia ligamettlina D¥.sn. {Jide Gabb, Pal. Cal., Vol. II, p. 73, 1869). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 249. Keep, West Coast Shells, p. 191, fig. 163, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185. Macoma {Rexithcerus') secta Con. = var. edulis (Nutt. mss.) Cpr. (fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1053). Shell large, suboval, slightly ventricose, rather thin; umbones subcentral, evenly rounded anteriorly; posterior end truncated obliquely much above the base line; posterior dorsal margins short, straight, sloping off quite steeply to angle where it meets line of truncation; fold prominent ; surface sculptured bylines of growth; two cardinal teeth in each valve; ligament short, thick, inserted on an elongated, oblique, rib-like callus; margin beneath the gape appearing as if cut or broken; pallial sinus large, expanded within, not reaching to anterior muscle-impression. Dimensions. — Long. 82 mm.; alt. 65 mm.; diam. 24 mm. Distinguishable by large size, broad shell, subcentral umbones, equal convexity of valves, and the prominent short ligamental callus. Resembles a Mactra somewhat in outline. Specimens identified by Dr. Dall. Found in the lower San Pedro series at Deadman Island and San Pedro; and in the upper San Pedro series at Deadman Island, Los Cerritos, Crawfish George's, San Pedro, and Long Beach. Found also in the Pleistocene at Spanish Right, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Bodega Bay to San Diego; Japan (Cooper). Pleistocene.— ^ani-A Barbara to San Diego (Cooper) : San Pedro; San Diego (Arnold). Pliocene. — Santa Barbara; San Fernando (Cooper). ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDRO. 165 110. Macoma yoldiformis Carpenter. Plate XVI, Fig. 6. Macoma yoldiformis Cpr., Brit. Assn. Rept. 1863, p. 639. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 249. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1053. Shell small, subelliptical, compressed, very thin and fragile; umbones slightly posterior to center; anterior end evenly rounded, longer than posterior side, which is very faintly folded, biangular and more cuneiform; surface smooth, except for very fine incremental lines; ligamental area scooped out about one-half length of posterior end; teeth very small. Dit?ie7tsions. — Long. 23 mm.; alt. 13.2 mm.; diam. 6 mm.; umbo to anterior extremity 13 mm.; to posterior extremity 10 mm. This species is distinguishable from other members of the genus by its small size, subelliptical form, very thin, smooth shell, posterior umbones and faint fold; distinguishable from Tellina hodegensis by less cuneiform posterior end and smaller size. Specimens identified by Dr. Dall. Rare in the lower San Pedro series at Deadman Island. Rather common in the Pleistocene at Spanish Bight, San Diego. The specimen figured is from this locality, and is now in the collection of Delos Arnold. Living. — Straits of Fuca to San Pedro (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold). Family XXXI. SEMELIDiE. Genus Semele Schumacher. Shell rounded, subequilateral, beaks turned forwards; posterior side slightly folded; hinge teeth two in right valve and two in left; laterals elongated, distinct in the right valve; external ligament short, cartilage internal, long, oblique; pallial sinus deep, rounded. Type, Tellina reticulata Spengler. III. Semele decisa Conrad. Amphidesma decisa CoN., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 234, PI. XIX, fig. 2. 5V?«f/if (/^ma Con., Carpenter, Proc. Zool. Soc, 1856, p. 213. Carpenter, Brit. Assn. Rept., 1863, p. 640. Gabb, Pal. Cal., Vol. II, p. 94, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Keep, West Coast Shells, p. 190, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 186. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 995. Shell rounded, subequilateral, thick; beaks elevated, turned forward; posterior side shorter than the anterior, direct, biangulated; fold distinct; anterior end evenly rounded; anterior dorsal margin slightly depressed; surface with numerous, thick, concentric, rugose, slightly prominent ribs; cartilage-process oblique; cardinal teeth obsolete; lateral teeth distinct; pallial sinus wide and shallow. Dimensio7is. — Long. 8.5 mm.; alt. 78 mm.; diam. 34 mm. The specimen described is a large one. These shells are often found in pairs in these deposits. . Specimens identified by Dr. Dall. 166 CALIFORNIA ACADEMY OF SCIENCES. Rare in the lower San Pedro series at San Pedro; common in the upper San Pedro series at Los Cerritos, but rarer in the same horizon at Deadraan Islam! and San Pedro. Found also in the Pleistocene at Twenty-sixth Street, San Diego. Living. — Santa Barbara to San Diego (Cooper). Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Arnold). 112. Semele pulchra Sovterby. Plate XV, Fics. 1 and la. Amphidesma pulchra Sv.Y . y Conch., Vol. Ill, No. 2, fig. 2. Semele pukhra Sby., Carpenter, Brit. Assn. Rept., 1863, p. 640. Gabb, Pal. Cal., Vol. II, p. 94, 1S69. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Keep, West Coast Shells, p. 190, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 186. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 995. Shell small, oval, thin ; beaks turned forward ; posterior sides shorter than the anterior, slightly biangular; fold not very distinct ; anterior dorsal margin slightly convex ; anterior end evenly rounded ; surface sculptured with numerous fine, sharp concentric ridges, and fine radiating striations; interior as in 6". decisa except more delicate, and cardinal tooth in each valve prominent. Dimensions . — Long. 22 mm.; alt. 18.2 mm.; diam. 6 mm. Distinguishable from 8. decisa by smaller, thinner shell, finer concentric sculpture and radiating striations. Specimens of the species in the State Museum Collection at the University of California, Berkeley, are labeled S. jiavescens Gld. Specimens identified by Dr. Dall. Rather rare in the upper San Pedro series at San Pedro and Los Cerritos. Found also in the Pleistocene at Twenty-sixth Street, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Santa Barbara to San Diego; Acapulco to South America (Cooper). Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Cooper; Arnold). 113. Semele pulchra So^rerby, montereyi, var. nov. Plate XV, Figs. 4 and 4a. Shell small, oval, ventricose, thin; beaks quite posterior to middle of shell; anterior dorsal margin long, nearly straight; anterior extremity evenly curved; posterior end much shorter than anterior, evenly rounded; fold obsolete; cartilage-process deep, oblique; one prominent cardinal tooth in each valve; lateral teeth distinct; pallial sinus very large, rounded, expanded interiorly. Dimensions. — Long. 23 mm ; alt. 17.5 mm.; diam. 11.5 mm. Resembles 8. pulchra in size, but is much more oval, lacking the angular appearance at the beak; the beaks are situated more anteriorly in var. montereyi and the shell is much more ventricose. Easily differentiated from the typical 8. pulchra. Pronounced a new variety of pulchra by Dr. Dall. Rare in lower San Pedro series at Deadman Island. ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDKO. 167 The specimen figured is not the type, which is larger, and is in the United States National Mnseum. The specimen fignred came from the lower San Pedro Series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Monterey (Dall). Pleistocene. — San Pedro (Arnold). Genus Cumingia Soiverbj. Shell transversely oval, equivalve, rounded in front, subrostrated and slightly gaping behind; small, thin, often irregular in form; hinge with a spoon-shaped cartilage-pit, and a small anterior cardinal tooth in each valve; two elongated lateral teeth in the right valve, less developed in the left; beaks small; surface concentrically ridged; pallial sinus very wide. Type, Cianingia mutica Sowerby. 114. Cumingia calif ornica Conrad. Cumingia californica Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 234, PI. XVII, fig. 12. Car- penter, Brit. Assn. Rept., 1863, p'. 640. Gabb, Pal. Cal., Vol. II, 1869, p. 94. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 238. Keep, West Coast Shells, p. 196, fig. 168, 1892. Williamson, Proc. U. S. Nat. Mas., Vol. XV, 1892, p. 186. ^C. similis A. Ad. {Jide Dall, Trans. Wagner Inst. Sci., Vol. Ill, part 5, 1900, p. 100 1 ). Shell of medium size, transversely oval, slightly venlricose, thin; umbones small, incon- spicuous; anterior margin evenly rounded; posterior sloping from umbo at an angle of about 45 degrees, straight; posterior end somewhat obliquely truncated; surface sculptured by numerous, about equidistant, sharp, narrow, concenlric ridges or frills; hinge with a triangular, spoon-shaped cartilage-pit and a small anterior cardinal tooth in each valve; two elongated lateral teeth in right valve, less developed in the left; pallial sinus very wide, expanded interiorly and deep. Dimensions. — Long. 24.5 mm.; alt. 18 mm.; diam. 4.9 mm. Resembles Macoma nasuta in general outline, but is easily distinguishable by the sharp, concentric ridges. Specimens identified by Dr. Dall. Found in the lower San Pedro series at Deadman Island and San Pedro, and in the upper San Pedro series at Deadman Island, Crawfish George's, and San Pedro. Living. — Monterey to San Diego; Mazatlan (Cooper): Japan (Stimson). Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro (Arnold). Family XXXII. PSAMMOBIID.E. Genus Psammobia (Lamarck) Bowdich. Subgenus Psammobia s. s. Shell elongated, more or less pointed behind; compressed; somewhat rudely concentrically sculptured; the posterior dorsal area frequently sculptured diversely from the disc; the pallial sinus elongated and for the most part coalescent below with the pallial line. Type, Psammohia feroehsis Grael. 168 CALIFORNIA ACADEMY OF SCIENCES. 115. Psammobia (Psammobia) edentula Gahb. Silequaria edcntiila Gabb, Pal. Cal., Vol. II, p. 53, PI. XV, tig. 11, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Psammobia edenhi/a Gabb, Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 976. Shell large, elongated, subelliptical, flattened, thin; beaks minute, posterior to middle; surface marked by distinct lines of growth most prominent near the margin; cardinal margins straight, sloping gently toward the ends; anterior end convexly and very obliquely subtruncate above, produced and rounded below; posterior end broadly and regularly rounded, a little less prominent below than above the middle; basal margin nearly straight; ligamental area long, pro- jecting prominently beyond the cardinal line for nearly half the length of the anterior portion of the shell; projected area with large groove on outside, flat on inside; two prominent cardinal teeth, anterior less prominent and oblique; anterior muscle-impression large, subcircular; posterior smaller, subelliptical; pallial sinus deep and wide. Dimetisions. — Long. 135 mm.; alt. 6g mm.; diam. 13 mm. This fine shell was originally described by Gabb from a specimen obtained in the Pliocene of San Fernando. On account of the matrix in which his specimen was imbedded, the hinge area and interior were only partly accessible, hence it was deemed expedient to more fully describe the interior of the shell. Dr. Dall pro- nounced the shell described above a member of the genus Psammobia. The cardinal teeth, however, are rather large for one of this genus. Rare in the upper San Pedro series of San Pedro; three good specimens obtained. Living. — ? Pleistocene. — San Pedro (Arnold). Pliocene. — San Fernando (Cooper). Genus Sanguinolaria Lamarck. Section Nuttallia Dall. Shell large, suborbicular, inequivalve, more or less twisted, the right valve slightly flatter; tiie posterior cardinal in the left valve obsolete; the pallial sinus narrow in front and somewhat detached from the p.illial line. Type, Sanguinolaria nultaUi Conrad. 116. Sanguinolaria (Nuttallia) nuttalli Conrad. Sanguinolaria nuttalli Con., Jour. Pliil. Acad. Sci., Vol. VII, 1837, p. 230, PI. XVII, tig. 6. Carpenter, Brit. Assn. Rept., 1863, p. 638. Keep, West Coast Shells, p. 19S, fig. 170, 1892. Williamson, Proc. U. vS. Nat. Mus., Vol. XV, 1892, p. 185. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 979. Shell large, subovate, thin; right valve ventricose, left compressed; umbones small, distant from anterior margin, slightly prominent, acute; surface smooth, e.xcept for fine incremental lines; anterior dorsal margin sloping concavely; posterior end evenly rounded from beaks; anterior end more sharply rounded and much more produced; ventral margin evenly curved; cardinal teeth prominent, fragile; ligamental area prominently projecting beyond cardinal line. Dimensions. — Long. 80 mm.; alt. 59 mm.; diam. 23 mm. ARNOLD — THE PALEONTOLOCxY AND STRATIGRAPHY OF SAN PEDRO. 169 Distinguishable from Mncoma by the prominent ligaraental projection, hinge, and less angular asj)ect. Sj^ecimens identified by Dr. Dall. Rather rare in the upper San Pedro series at San Pedro and Los Cerritos. • Living. — Santa Barbara to San Diego (Carpenter). Pleistocene. — San Pedro (Arnold). Genus Tagelus Gray. Beaks median or subposterior; teeth two in each valve, simple, pedunculate; valves without constriction or clavicle, straight; pallial sinus deep, reaching to or beyond the beaks; posterior adductor scar rounded; pallial sinus with the ventral part partially coalescent with the pallial line. Type, Solen gihhus Spengler. 117. Tagelus calif ornianus Conrad. Soleciirliis calif orniajnis don., ]o\n. Phil. Acad. Sci., Vol. VII, 1837, p. 233, PI. XVIII, fig. 3. Carpenter, Brit. Assn. Rept., 1863, p. 638. Cooper, 7th Ann. Rcpt. Cal. St. Min., 1888, p. 265. Keep, West Coast Shells, p. 201, fig. 172, 1892. Tagelus calif ornianus Coi^., Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 184. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 984. Shell of medium size, oblong-oval, convex, thin; umbones about central; posterior dorsal margin runs straight back from umbo parallel with base; anterior dorsal margin slightly depressed, beginning a little below and in front of umbo, parallel with base; extremities evenly rounded; basal margin slightly contracted in middle; ligamental area slightly projecting; cardinal teeth, two in each valve, sharp and thin; pallial sinus long and wide, pointed. Dimensio7is. — Long. 80 mm.; alt. 22 mm.; diam. 13 mm. Specimens identified by Dr. Dall. Rare in the lower San Pedro series at Deadman Island and San Pedro; com- mon in the upper San Pedro series at Deadman Island, Los Cerritos, Crawfish George's, San Pedro, and Long Beach. Also found in the Pleistocene at Twenty- sixth Street, San Diego. Living. — Santa Barbara to San Diego (Cooper). Pleistocene. — Santa Barbara; San Pedro; San Diego (Cooper): San Pedro; San Diego (Arnold). Pliocene.^San Diego (Dall). Family XXXIIl. DONACID^. Genus Donax (Linne) Lamarck. Shell elongate, smooth, with no posterior carination; ventral margins with obsolete serra- tion; cardinal teeth two in each valve, the larger often bifid; laterals both in the left valve, the anterior hardly distinguishable from the margin, of which it is a sort of modification. Donax trunculus Linne is a characteristic species. (22) January 10, laoa. 170 CALIFORNIA ACADEMY OF SCIENCES. ii8. Donax californica Conrad. Plate XIII, Fig. 9. Donax californica Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 254, PI. XIX, fig. 21; (not of Carpenter, Brit. Assn. Rept., 1863, p. 640.); (not of Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 238); (not of Keep, West Coast Shells, p. 192, fig. 164, 1892); (not of Williamson, Proc. U. S. Nat. M us., Vol. XV, 1892, p. 186). = /?. navicula Hanley (fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 968). Donax flexiiosus (not of Gould, Bost. Jour. Nat. Hist., Vol. VI, 1857, p. 394, PI. XV, fig. 8); (not of Cpr., Brit. Assn. Rept., 1863, p. 640). ? Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 238. Keep, West Coast Shells, p. 192, 1892. ? Williamson, Proc. U. vS. Nat. Mus., Vol. XV, 1892, p. 186. Shell small, elongate-oval, rather pointed at both ends, thin; anterior end produced, quite sharply rounded; posterior portion over one-half length of anterior, rounded end; surface obscurely sculptured with fine radiating furrows; concentric, incremental sculpture sometimes visible; hinge and teeth as in D. laevigata except more delicate; interior of margin finely crenulated. Dimensions. — Long. 18 mm.; anterior portion 11 mm.; posterior 7 mm.; alt. 8 mm.; diam. 6 mm. Distinguishable from D. hmngata by smaller, narrower, thinner shell, more elongated posterior portion and much less steeply sloping dorsal margin on this end. This is the true D. californica Conrad, and not the californicas of Carpenter and other later writers (see synonymy above). Specimens identified by Dr. Dall. Rare in the lower San Pedro series at Deadmaii Island and San Pedro; and in the upper San Pedro series at San Pedro. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Santa Barbara to San Diego (Cooper). Pleistocene. — San Pedro (Arnold). 119. Donax laevigata De.shayes. Plate XIII, Fig. 8. Donax IcBvigata Deshayes, Proc. Zool. Soc, 1854, p. 352. Reeve, Conch. Icon., Vol. VIII, PI. V, fig. 31. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 969. Donax cali/ornicus (not. of Conrad, Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 254, PI. XIX, fig. 21). Carpenter, Brit. Assn. Rept., 1863, p. 640. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 238. Keep, West Coast Shells, 192, fig. 164, 1892. Williamson, Proc. U. S. Nat. Mas., Vol. XV, 1892, p. 186. Donax obesus, Gld., Proc. Bost. Soc. Nat. Hist., Vol. IV, 1851, p. 90; Bost. Jour. Nat. Hist., Vol. VI, p. 394, PI. XV, fig. 9, 1857. Shell rather small, trigonal, convex, wedge-like, closed; anterior portion produced, rounded, upper margin straight; posterior portion very short and dorsal margin nearly straight, also angulated at base; surface obscurely sculptured by fine radiating lines; incremental sculpture generally visible; interior of margin strongly crenulated; hinge teeth two in each valve; laterals one anterior and one posterior in each valve; pallial sinus deep. Dimensions. — Long. 20.5 mm.; anterior portion 14 mm.; posterior 6.5 mm.; alt. 12 nnn.; diam. 8 mm. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 171 This is the coraiuon Donax of the West Coast, and is easily recognized by its triangular shape and the short, straight, posterior end. This species has been erroneously called californicus by Carpenter and others since then, but a comparison of one of these shells with Conrad's original figure and description of californica readily shows the error. The true californica Conrad has a rather produced and rounded posterior end, and is much narrower than kevigata. Specimens identified by Dr. Ball. Rare in the lower San Pedro series at San Pedro and Deadman Island; common in the upper San Pedro series at San Pedro, Los Cerritos, Crawfish George's, Long Beach, and Deadman Island. Found also in the Pleistocene at Barlow's ranch, Ventura; and at Spanish Bight, Twenty-sixth Street, and Pacific Beach, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Monterey?; San Luis Obispo to San Diego (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego; Ventura (Arnold). Superfamily SOLENACEA. Family XXXIV. SOLENID^. Genus Solen Linne. Hinge with one cardinal in each valve; beaks nearly anterior; external surface polished; valves usually straight. Type, Solen marginatus Pulteney. 120. Solen rosaceus Carpenter. Solen {stearins ? var.) rosaceus Cpr., Brit. Assn. Rept., 1S63, p. 638; Ann. & Mag. Nat. Hist., 3rdSer., Vol. XV, 1865, p. 177. KSb/f« ;wac«/j Cpr., Gabb, Pal. Cal., Vol. II, p. 88, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888. p. 265. Keep, West Coast Shells, p. 202, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 184. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 952. Shell of medium size, long, subcylindrical, slightly falcate, margins parallel, ends gaping; beaks terminal; anterior extremity evenly rounded, projecting furthest a little below the middle; posterior extremity very long, evenly rounded; hinge-teeth, one in each valve; ligament long, ex- ternal; anterior muscle-impressions elongated; posterior oblong; sinus with squarish corners. Dimensions. — Long. 55 mm.; alt. 10.5 mm.; diam. 6 mm. This species much resembles S. sicarius but is much longer and narrower, more cylindrical, and has a much more evenly rounded and less abruptly truncated anterior extremity. Found also in the Plei.stocene at Spanish Bight, San Diego. Living. — Santa Barbara south to Gulf of California (Dall). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold): San Diego (Dall; Arnold). 172 CALlFOENIA ACADEMY OF SCIENCES. Pliocene. — Santa Rosa; San Ramon, Kirker's Pass, Contra Costa County; San Fernando; San Diego well (Cooper). Miocene. — Toraales, Marin County; Martinez, Contra Costa County (Cooper). 121. Solen sicarius Gould. Solen stearins Gv.T>. , Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1850, p. 214; Wilkes' Expl. Exped., Vol. XII, p. 287, fig. 501, 1852. Carpenter, Brit. Assn. Rept., 1863, p. 638. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 265. Keep, West Coast Shells, p. 202, fig. 173, 1892. Williamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 184. Dall, Trans. Wagner Inst. Sci. , Vol. Ill, Part 5, 1900, p. 952. Shell of medium size, elongated, transversely oblong, cylindrical, slightly falcate; beaks terminal; anterior extremity truncate obliquely at angle of about 30 degrees, somewhat everted, the portion posterior to a line across from the beak to the base, concave; posterior extremity rounded; dorsal edge rectilinear; ventral edge regularly arcuate; surface undulated by lines of growth; hinge with single, erect, recurved, triangular tooth in each valve. Diine7isions. — Long. 63 mm.; alt. i6mm. ; diam. 9'mm. Distinguishable by its terminal beak and rather falcate outline. Specimens identified by Dr. Dall. Rather rare in the Pleistocene at Deadman Island and Timra's Point; com- mon in the lower San Pedro series at Deadman Island and San Pedro; rare in the upper San Pedro series at Los Cerritos, San Pedro, Crawfish George's, and Deadman Island. Living. — Straits of Fuca to San Pedro; Japan (Cooper). Pleistocene. — San Pedro (Arnold). Pliocene. — Twelve Mile Creek, San Mateo County; San Fernando (Cooper). Miocene. — Walnut Creek, Contra Costa County (Cooper). Genus Siliqua Megerle. Shell smooth, oblong; epidermis polished; an umbonal rib extending across tiie interior of the valve; pallial sinus short. Type, Solen radius Linne. 122. Siliqua lucida Conrad. bolecurtus lucida Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 232, PI. XVII, fig. 9; ^6". radiata Linn, {^fide Conrad, Jour. Phil. Acad. Sci., 1849, p. 214). Dall, Solenidae, Proc- U. S. Nat. Mus., Vol. XXII, igoo, p. 109. Siliqua lucida Con., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 957. Shell of medium size, oblong-oval, compressed, thin, fragile; umbo a little less than one- fourth length from posterior end; interior raised callus sharp, narrow, perpendicular to dorsal margin; other characteristics the same as in var. nuitalli. Dimensions.— hong. 32 mm.; alt. 12 mm.; diam. 5 mm.; umbo to anterior end 25 mm.; to posterior end 7 mm. ARNOLD — THE PALEONTOLOGY ANt) STRATIGRAPHY OF SAN PEDRO. 173 This species is distinguishable from var. nuttalli by its small size, fragile shell, more posterior umbo, and sharper, narrower, shorter, and more nearly perpendicular interior callus. Dr. Dall in his paper on the Solenidte says that Carpenter (Brit. Assn. Rept., 18G3, p. 634) and Gabb (1868) have confounded the young of S. nuttalli with this species. A large series of S. lucida from the Pleistocene shows the above mentioned differentiating characteristics to be constant. Specimens identified by Dr. Dall. Rather rare in the lower San Pedro series at Deadman Island and San Pedro; and in the upper San Pedro series at San Pedro and Los Cerritos. Found also in the Pleistocene at Twenty-sixth Street and Spanish Bight, San Diego. Living. — Monterey to San Diego (Dall). Pleistocene. — San Pedro; San Diego (Arnold). 123. Siliqua patula (Dixon) var. nuttalli Conrad. Solecurtus 7mtlalli arlow's ranch, Ventura, and at Twenty-sixth Street, Spanish Bight, and Pacific Beach, San Diego. Living. — Santa Barbara to San Diego (Cooper). '"'^d^v Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego; Ventura (Arnold). Pliocene. — San Diego well (Dall): San Pedro (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 199 Family LI. CONID.E. Geuus Conus Linne. Shell thick, obconic, whorls enrolled upon themselves, the spire short, or not elevated, smooth or tuberculated; aperture long, narrow, the margins parallel, truncated at the base; the outer lip with a slight sutural sinus. Conus nuirniorens Linn, is a characteristic species. 162. Conus californicus Hinds. Conus californicus Hus., Proc. Zool. Soc, 1844; Voy. Sulphur, p. 7, PI. I, figs. 3, 4, 5, 1844. = C. ravus Gld. {fide Cpr., Brit. Assn. Rept., 1863, p. 65S). Gabb, Pal. Cal., Vol. II, p. 78, 1869. Tryon, Man. Conch., Vol. VI, p 17, PI. IV, figs. 62, 63, 1884. Cooper, 7th Ann. Rept. Cal. St. JNIin., 1888, p. 236. Keep, West Coast Shells, p. 54, 1892. Shell double-conical; spire compact, elevated; apex subacute; whorls seven or eight, flat, smooth, except for incremental lines; suture irregular, appressed; body-whorl conical, subangular anteriorly, spirally ornamented with fine lines, which are most prominent on lower part of whorl; aperture long, narrow, slightly wider anteriorly; outer lip thin, bulging anteriorly; obsolete pos- terior sinus. DimeJisions. — Long. 34 mm.; lat. iS mm.; body-whorl 29 mm.; aperture 27.5 mm.; defl. 83 degrees. The specimens from the Pleistocene are generally much worn, but some of them retain the reddish brown coloration of the spiral lines and upper part of the whorls. Not uncommon in the Pliocene at Deadman Island and Timm's Point; in the lower San Pedro series at Deadman Island and San Pedro; very common in the upper San Pedro series at Deadman Island, Crawfish George's, Los Cerritos, San Pedro, and Long Beach. Found also at Spanish Bight and Pacific Beach, San Diego. Living. — Farallon Islands to San Diego; Lower California (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego (Arnold). Pliocene. — San Fernando (Cooper): San Pedro; Stanford University (Arnold). Family Lll. PLEUROTOMID.E. Genus Pleurotoma Lamarck. vShell turriculated, fijsiform, terminated anteriorly by a straight, more or less long canal; aperture oval; columellar lip smooth, straight or sinuous; outer lip somewhat sinuous, with a pos- terior sinus. Pleurotoma hahijlonia Lara, is a characteristic species. 200 CALIFORNIA ACADEMY OF SCIENCES. 163. Pleurotoma perversa Gahb. Pleicrotoma perversa Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 183; Pal. Cal., Vol. 11, pp. 6, 73, PI. I, fig. ID, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., i888, p. 260. Snrcula perversa, Gabb, Tryon, Man. Conch., Vol. VI, p. 239, PI. VI, fig. 79, 1884. Shell small, sinistral, elongate, slender; whorls eight to eleven, convex; surface smooth except lor fine incremental lines which are convexly angulated posteriorly a little above middle of whorl; suture deeply impressed, distinct; aperture elongate-ovate; outer lip arcuate anteriorly; inner lip incrusted; columella smooth; posterior sinus prominent; anterior sinus long, narrow. Dimensions. — Long. 42 mm.; lat. 11.5 mm.; body-whorl 21 mm.; aperture, including canal, 16 mm.; defi. 18 degrees. Distinguishable from other member.-? of thi.s family by being sinistral. Common in the Pliocene and lower San Pedro series at Deadman Island; in lower San Pedro series at San Pedro; and rare in the npper San Pedro series at Deadman Island, San Pedro, and Los Cerritos. Common in upper San Pedro series at Crawfish George's. Living. — Vancouver Island to Cutalina Island (Coojser). Pleistocene. — Santa Barbara to San Pedro (Coojier) : San Pedro (Arnold). Pliocene. — San Pedro (Arnold). Subgenus Borsonia Bdlardi. Shell fusiform; with a plication upon the middle of the columt'll.i. Pleurotoma j^yrenaica Roualt is a characteristic species. 164. Pleurotoma (Borsonia) bartschi, sp. nov. PL.4TE V, Fig. 7; Plate IX, Fig. 1. Shell small, fusiform, elongate; apex obtuse, mammilliform; whorls seven, angulated near middle; body-whorl less angulated than those of spire; anterior portion of whorl ornamented with about twelve oblique, transversely elongated nodes, which reach their greatest prominence on the angle of the whorl; body-whorl sometimes smooth and sometimes nodose; posterior portion of whorl flat and smooth except for incremental lines; incremental lines fine, oblique, and angulated convexly posteriorly on upper portion of whorl; suture deeply appressed, distinct; aperture elongate-elliptical; outer lip thin, arcuate anteriorly below posterior sinus; inner lip incrusted; columella nearly straight, incrusted, with one sharp plication in middle of aperture; posterior sinus shallow; anterior sinus prominent. Dimensions. — Long. 19 mm.; lat. 7 mm.; body-whorl 11. 5 mm.; aperture, including canal, 8.5 mm.; defi. 28 degrees. Distinguishable from B. dallii and B. hooveii by the prominent nodes on the whorls. Looks very much like Drillin tnrosa, but is easily distinguishable by the plication on columella and more angulated body-whorls. Pronounced a new species by Dr. Dall. Specimens of Borsonia bartschi in the State Museum collection of fossils at Berkeley are labeled "Drillia mutsta." ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 201 Rare in the Pliocene and lower San Pedro series at Deadman Island. The spe- cimen figured on Plate IX is the type, which is from the lower San Pedro series at Deadraan Island, and is now in the United States National Museum; the specimen figured on Plate V is a stumpy form, which might be called variety curta. Pleistocene. — San Pedro (Arnold). Pliocene. — San Pedro (Arnold). 165. Pleurotoma (Borsonia) dalli, sp.nov. Plate VI, Fig. 2. Shell small, fusiform; spire elevated; ape.x mammilliform; whorls eight, sharply angulated a little anterior of middle; body-whorl less angulated than those of spire; posterior portion flat to slightly concave, anterior portion slightly conve.x; first four whorls slightly nodose on angle; orna- mentation consists of fine oblique, incremental lines which are convexly angulated posteriorly just posterior to angle of whorl; suture deeply impressed, distinct; aperture elongate-elliptical; outer lip thin, arcuate anteriorly; inner lip incrusted; columella slightly recurved, with one prominent plication in middle of aperture; posterior sinus prominent; anterior sinus rather short. Dime7isions. — Long. 23.5 mm.; lat. 9 mm.; body-whorl 13 mm.; aperture, including canal, 10 mm.; defl. 27 degrees. Distinguishable by mammilliform apex, small deflection, sharply angulated, smooth whorls, and plication on columella. Specimens pronounced new species by Dr. Dall. Rare in lower San Pedro series and Pliocene at Deadman Island. The speci- men figured is tiie type, which is from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Pliocene. — San Pedro (Arnold). 166. Pleurotoma (Borsonia) hooveri, sp. nov. Plate X, Fig. 1. Shell small, fusiform; apex mammilliform; whorls five or six, angulated slightly anterior to middle; body- whorl less angulated than those of spire; surface smooth, except for incremental lines, which are oblique, and angulated convexly posteriorly a little above angle of whorl; suture deeply impressed, distinct; aperture elliptical; outer lip thin, arcuate anteriorly below posterior sinus; inner lip incrusted; columella incrusted, straight, with one prominent plication in middle of aperture; pos- terior sinus shallow; anterior sinus short. Dimensions. — Long. 13 mm.; lat. 6.5 mm.; body-whorl 8.2 mm.; aperture, including canal, 6.5 mm.; defl. 50 degrees. Distinguishable from B. dallii by greatly depressed spire, fewer whorls and lack of nodes on apical whorls. Pronounced a new species by Dr. Dall. Rare in lower San Pedro series; two found at Deadman Island. The speci- men figured is the type, which is from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). ( 26 ) March 12, \WJ. 202 CALIFORNIA ACADEMY OF SCIENCES. Subgenus Leucosyrinx Dull. 167. Pleurotoma (Leucosyrinx) pedroana, sp. nov. Plate IX, Fig. 4. Shell small, elongated; ape.x subacute; whorls six, sharply angulated near anterior margin; upper portion of whorls flat; ornamentation consists simply of incremental lines, which are angulated convexly posteriorly a little posterior to the angle of the whorl; lower portion of body-whorl, and sometimes the lower portion of the upper whorls, faintly spirally ribbed; deep sutural canal; aperture ovate; outer lip thin, bulging anteriorly; inner lip smooth; posterior rims shallow and wide; canal long, narrow; columella slightly recurved. Dimensio7is. — Long. 17 mm.; lat. 6 mm.; body-whorl 10 mm.; aperture 7 mm.; defl. 22 degrees. Distinguishable by the deep, canal-like suture and the prominence of the angulation on the lower part of the whorls. Specimens identified by Dr. Dall as being new. Rare in lower San Pedro series at Deadman Island; three specimens found. The specimen figured is the type, which is from the lower San Pedro series at Dead- man Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Subgenus Genota Adams. Section Dolichotoma Bellardi. Shell mitrieform; whorls finely cancellated; aperture elongated, canal short; sinus profound. Pleurotoma mitrceformis Kiener is a characteristic species. 168. • Pleurotoma (Dolichotoma) carpenteriana Gahb. Pkurotoina (Siircida) carpenteriana Gabb, Proc. Cal. Acad, Sci., Vol. Ill, 1865, p. 183; Pal. Cal., Vol. II, pp. 5, 72, PI. I, fig. 8, 1869. Siircula carpenieria7ia Gabb, Tryon, Man. Conch., Vol. VI, p. 239, PI. VII, fig. 3, 1884. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 266. Keep, West Coast Shells, p. 57, fig. 41, 1892. Genota carpenteriana Gabb, Dall, Proc. U. S. Nat. Mus., Vol. XII, 1889, p. 303. Pleurotoma (Dolichotoma) carpejiteriajia Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 207. Shell large, fusiform; spire elevated and about as long as the aperture; whorls eight, sub- flattened on the sides, slightly concave near suture, and very slightly convex anteriorly; surface ornamented with fine spiral ridges, which alternate in size on lower part of body-whorl; suture im- pressed; aperture narrow, widest in middle; outer lip thin, arcuate anteriorly below the wide, shallow sinus; inner lip smooth, incrusted; canal broad and short. Dimensions. — Long. 88 mm.; lat. 33 mm.; body-whorl 66 mm.; aj^erture, including canal, 50 mm.; defl. 38 degrees. The specimen described is an exceediugly fine specimen, a little above the average in size. Mrs. Oklroyd has over a dozen fine specimens of the living shells of this species, which have been hauled up in the fishermen's nets at San Pedro. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 203 Not uncommon in the upper San Pedro series at San Pedro, Deadman Island, and Crawfish George's. Found also in the Pleistocene at Pacific Beach, San Diego, and at the old irrigating ditch, Ventura. Living. — Monterey to San Diego (Cooper): Cerros Island (Dall). Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro; San Diego; Ventura (Arnold). Pliocene. — Santa Rosa; San Fernando (Cooper): San Diego well (Dall). 169. Pleurotoma (Dolichotoma) cooperi, sp. nov. Plate VII, Fig. 3. Shell large, fusiform; spire elevated, same length as aperture; whorls seven, prominently angulated near middle; upper portion decidedly concave, lower portion slightly convex; first five whorls slightly nodose on angle, rest of whorls smooth on angle, except for roughness caused by in- cremental lines; surface ornamented with revolving spiral ridges, most prominent on the lower portion of whorls, and with prominent incremental lines, which, following the outline of the lip, are convexly angulated posteriorly on the upper portion of the whorl and concavely angulated on the lower portion; on the upper whorls the nearly equal prominence of the two systems of sculpture give the shell a cancellated appearance; aperture long, narrow, with sides nearly parallel; outer lip thin, arcuate anteriorly below sinus; inner lip smooth, incrusted; posterior sinus shallow, broad; canal short, nearly as wide as aperture. Dimensions. — Long. 65 mm.; lat. 24 mm. ; body- whorl 42.5 mm.; aperture, including canal, 33 mm.; defl. 39 degrees. Distinguishable by the decided convexity of the upper portion of the whorl, smooth angle and cancellated appearance of upper whoi'ls. Rare in upper San Pedro series of San Pedro; one specimen found. The specimen figured is the type, which is from the upper San Pedro series at San Pedro, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). 170. Pleurotoma (Dolichotoma) tryoniana Gabb. Pleurotoma ( Siircula) tryo7iiana Gabb, Pal. Cal., Vol. II, p. 6, PI. I, fig. 9, 1869. Sicrcula t>yoyiiana Gabb, Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 266. Shell resembles P. carpenteriana in shape; whorls eight, convex anterior to middle, with row of nodes on angle; upper portion of whorls concave; surface ornamented with revolving ridges, rather coarser on lower portion of whorl; suture impressed; aperture elongate, narrow, widest in middle; outer lip thin, bulging below the wide, shallow sinus; inner lip smooth; canal short, broad. Dimejisiojis. — Long. 75 mm.; lat. 28 mm.; body-whorl 52 mm.; aperture, including canal, 40 mm.; defl. 33 degrees. Distinguishable by nodose, convex, angular whorls. Rare in upper San Pedro series of San Pedro. Mrs. Oldroyd has several specimens of this species, which have been hauled up alive in the fishermen's nets at San Pedro. Living. — San Diego (Cooper): San Pedro (Oldroyd). Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold). 204 CALIFORNIA ACADEMY OF SCIENCES. Genus Drillia Gray. Shell turriculated; aperture oval, oblique; canal short, twisted; columella lip strongly callous above. Pletiratoma (jibhosa Kiener is a characteristic species. 171. Drillia cancellata Carpenter. Drillia canal/afa Cv^., Brit. Assn. Rept., 1863, p. 658; Proc. Phil. Acad. Nat. Sci., 1865, p. 63. Tryon, Man. Conch., Vol. VI, p. 183, 1884. Shell resembles D. hiermis in shape; whorls eight or nine, nearly flat, but slightly angulaled near anterior margin; decoration consists of five to six spiral ridges and about twenty-five rather more prominent transverse, slightly oblique ribs, the whole giving the whorls a cancellated appear- ance; suture impressed, distinct; canal long, prominent. The four specimens found were youug, and no adult lias so far been recorded from this formation. Found in the lower San Pedro series of Deadman Island, and in the upper San Pedro series of Los Cerritos. Found in the Pleistocene at Spanish Bight, San Diego. Living. — Puget Sound (Carpenter). Pleistocene. — San Pedro; San Diego (Arnold). 172. Drillia hemphilli Stearns. ' Plate V, Fio. 8. Drillia hemphilli Stearns, Proc. Cal. Acad. Sci., Vol. V, 1874, p. 80, PI. I, fig. 3. Tryon, Man. Conch., Vol. VI, p. 185, PI. XIII, fig. 49, 1884. Shell small, elongate, slender; apex acute; whorls eight, slightly convex, with fifteen distinct, transverse, slightly oblique, rounded ribs; flat anterior sutural riblet about one-fifth the width of whole whorl; suture impressed, distinct; spiral sculpture consists of a few faint grooves; outer lip thin, bulging anteriorly below posterior sinus, which is deep and narrow; anterior sinus short; inner lip and inner side of columella incrusted. Dimetisions. — Long. i6nmi.; lat. 5 mm.; body-whorl 8 mm.; aperture, including canal, 5.5 mm.; defl. 20 degrees. The speciinen described is the largest one found, the normal length being about 10 mm. Distinguishable by its small size, prominent sutural riblet, and oblique transverse ridges. Found in lower San Pedro series of Deadman Island and San Pedro, and in the upper San Pedro series of Los Cerritos, San Pedro, and Crawfish George's. Found in the Pleistocene at Barlow's ranch, Ventura; and at Spanish Bight and Twenty-sixth Street, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Lower California (Stearns). Pleistocene.— ^an Pedro; Ventura (Arnold): San Diego (Stearns; Arnold; Hemphill). ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO. 205 [S. D.] Drillia incisa Carpenter. Drillia incisa CpR., Brit. Assn. Rcpt., 1863, p. 657. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 239. Shell like D. inermis, except that the spiral sculpture consists of several impressed grooves. Found in the Pleistocene at Pacific Beach, San Diego. Living. — Straits of Fiica to Santa Cruz (Cooper). Pleistocene. — Santa Barbara to San Pedro (Cooper): San Diego (Arnold). 173. Drillia inermis Hinds. Plate V, Fig. 10. Pleurotoma inermis Hds., Proc. Zool. Soc, 1843, p. 37; Voyage Sulphur, p. 16, PL V, fig. 8, 1844. Drillia inermis Hds., Cpr., Brit. Assn. Kept., 1863, p. 657. Gabb, Pal. Cal., Vol. II, p. 72, 1869. Tryon, Man. Conch., Vol. VI, p. 182, PI. XII, figs. 40 and 43; PI. XXXII, fig. 42, 1884. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 239. Shell elongate, slender; spire elevated; apex acute; whorls eight or nine, slightly angulated a little posterior to middle, the posterior portion being slightly concave, and the anterior portion slightly convex; ornamentation consists of nine to eleven rounded, spiral ridges, and numerous prominent transverse ridges following th.e lines of growth, which are convexly angulated on the angle of whorl; the ornamentation is more prominent on the lower portion of the whorls; suture impressed, distinct; aperture elliptical; outer lip thin, arcuate anteriorly; posterior sinus shallow; anterior sinus rather long; inner lip and inner portion of columella incrusted; columella slightly recurved. Dimensions. — Long. 30 mm.; alt. 9 mm.; body-whorl 17 mm.; aperture, including canal, II. 5 mm.; defl. 22 degrees. Distinguishable from D. penicillata by longer canal, angulation of whorls, and greater prominence of ornamentation; distinguishable from D. cancellata by less deflection and angulation of whorl, except body-whorl, which is more evenly convex than in the latter. Rare in lower San Pedro series of Deadman Island, and in the upper San Pedro series of Los Cerritos and San Pedro. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Found in the Pleistocene at Barlow's ranch, and the old irrigating ditch, Ventura; and at Spanish Bight and Pacific Beach, San Diego. Living. — Santa Barbara to San Diego; Lower California (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego; Ventura (Arnold). 174. Drillia inermis var. penicillata Carpenter. Drillia penicillata CpR., Brit. Assn. Rept., 1863, p. 658; Jour, de Conch., Vol. XIII, 1865, p. 146. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 239. Keep, West Coast Shells, p. 56, fig. 38, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 208. Pleurototna penicillata Cpr., Tryon, Man. Conch., Vol. VI, p. 1S2, PI. XII, fig. 40, 1884. Shell elongated; spire elevated; apex acute; whorls eight, only slightly convex; ornamented with numerous nearly obsolete, rounded, spiral ridges, and fine incremental lines which, reproducing 206 CALIFORNIA ACADEMY OF SCIENCES. the outline of the lip and posterior sinus, form in the middle of the whorl an angle open anteriorly; transverse ornamentation more prominent on apical whorls; suture impressed, distinct; aperture elliptical; outer lip thin, arcuate anteriorly; posterior sinus shallow, wide; anterior sinus short; columella slightly curved to left; spirally ridged. Dimensions. — Long. 26.5 mm.; lat. 9 mm.; body-whorl 14.5 mm.; aperture including canal, 11 mm.; defl. 22 degrees. Distinguishable by the beautiful wavy incremental lines, which are quite l^rominent in most specimens. Some of the shells reach a length of 40 mm. (jrades imperceptibly into D. inennis. Not uncommon in the lower San Pedro series at Deadman Island and San Pedro, and in the upper San Pedro series at Deadman Island, San Pedro, Los Cerritos, Long Beach, and Crawfish George's. Found in the Pleistocene at Spanish Bight and Pacific Beach, San Diego; and at the old irrigating ditch and Barlow's ranch, Ventura. Living. — San Pedro, south; Cerros Island; Lower California (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro (Arnold). 175. Drillia johnsoni, sp. nov. Plate VIII, Fig. 17. Shell of medium size, turreted; whorls eight or nine, nearly flat, each crossed by about thirteen prominent, rounded, equal, equidistant, oblique ribs, which begin at anterior portion of whorl and extend for about two-thirds distance across whorl, where they become nearly obsolete; a sutural band occupies the upper third of the whorl; lower portion of whor! with five deep, channel-like sulcations; sutural band with strong, oblique incremental lines; suture appressed, undulating; aperture subelliptical; outer lip arcuate; posterior sinus narrow, rather deep; anterior sinus short, recurved; columella incrusted; body-whorl convex, extended below, with revolving sulcations on lower portion; transverse ridges obsolete on lower portion. Diynensions — Alt. 32 mm.; lat. 11 mm.; body-whorl 16. 8 mm.; aperture, including canal, 12 mm.; canal 2 mm.; defl. 25 degrees. Resembles P. montereyensis, but is distinguishable by larger size, less promi- nent but more sculptured sutural band, longer and more oblique ribs, and more numerous spiral sulcations. Distinguishable from P. aurantia by much larger size, more prominent and more sculptured sutural band, more distinct spiral sulcations, longer and less oblique aperture, and a recurved rather than a straight anterior sinus. Pronounced a new species by Dr. Dall. Named in honor of Henry R. Johnson of Washington, D. C, who has prepared many of the drawings used in illustrating this paper. Type specimen from upper San Pedro series of San Pedro. The specimen figured is the type, which is now in the United States National Museum. Found also in the upper San Pedro series at Deadman Island by W. B. Barber. Pleistocene. — San Pedro (Arnold; Barber). ARNOLD -THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 207 176. Drillia merriami, sp. no v. Plate VIII, Fig. 7. Shell small, fusiform, rather thin; ape.x blunt; whorls seven, somewhat angular, with about fourteen slightly oblique, prominent, rather sharp transverse ridges; these ridges are most prominent on angle of whorl, and become obsolete near anterior margin and at about one-third width of whorl from posterior margin; a narrow sutural band occupies upper one third of whorl; incremental lines visible; suture deeply impressed, distinct; body-whorl somewhat ventricose and narrowed anteriorly, with transverse ribs sometimes obsolete; aperture broadly elliptical, narrowed anteriorly to a promi- nent sinus; posterior sinus small, near suture; outer lip arcuate, thin; columella smooth. Ditnenst07is. — Long. 14.2 mm.; lat. 5.2 mm.; body-whorl 7.6 mm.; aperture, including canal, 6 mm.; canal 1.5 mm.; defl. 31 degrees. Thi.9 species somewhat resembles Borsonia hartschi, bat may be distinguished by lack of columellar plait, longer but less oblique transverse ridges, and narrower sutural band. Distinguishable from I), hemphilli by lack of spiral sulcations, less oblique ribs, much longer body-whorl, and much more prominent canal. Dis- tinguishable from D. torosa by lack of sjiiral lines, narrower sutural band, less convex whorls, and more and longer ribs. This species is said by Dr. Dall to be near the Panama species B. pallida Sby. Named in honor of Dr. John C. Merriam, Pro- fessor of Paleontology in the University of California, who has assisted the writer in many ways in the jDreparation of this paper. Rare in Pliocene and lower San Pedro series of Deadman Island. The specimen figured is the type, which is from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Pliocene. — San Pedro (Arnold). 177, Drillia montereyensis Stearns. Pkurotoma (Drillia) mojiiereyensis Stearns, Proc. Cal. Acad. Sci., Vol. V, 1873, p. 80, PI. I, fig. 21. Tryon, Man. Conch., Vol. VI, p. 184, PI. XII, fig. 30, 1884. Shell small, elongate, slender; seven moderately rounded whorls, upper portion of volutions concavely angulated and ornamented with fine spiral ribs and furrows; middle of upper whorls and upper part of body- whorl displaying fifteen equidistant, longitudinal, nodose, slightly oblique ribs; on the smaller volutions of the spire a puckering at and following the suture suggests a second indistinct series of nodules; aperture less than half the length of shell; canal short; posterior sinus rather broad, rounded and of moderate depth. Dimensions. — Long. 15 mm.; lat. 6 mm.; body-whorl 8.4 mm.; aperture 6 mm.; defl. 22 degrees. Resembles a large D. liemphilli in shape, but has a very distinctive orna- mentation. Rare in the lower San Pedro series at Deadman Island; of the two specimens found, one was obtained by Mrs. Oldroyd. Living. — Monterey (Stearns). Pleistocene. — San Pedro (Oldroyd; Arnold). 208 CALIFORNIA ACADEMY OF SCIENCES. 178. Drillia pudica Hinds. Plate VIII, Fig. 13. Pleurotoma pudica Hds., Proc. Zool. Soc, 1843, p. 41; Voyage Sulphur, p. 20, PI. VI, fig. 11, 1844. Cpr., Brit. Assn. Rept., 1856, p. 330. Tryon, Man. Conch., Vol. VI, p. 189, Pi. XIII, fig. 55, 1884. Shell small, resembling D. torosa in general appearance; whorls seven, angular, convex below, concave above, with twelve or thirteen transverse ribs, nearly all of which extend from suture to suture, but less prominent on the concave surface; surface spirally sulcate; in other respects similar to torosa. DimensioJis. — Long. 11 mm.; lat. 4 mm.; defl. 25 degrees. Distinguishable from I), torosa by the long transverse ribs, and by the more convex outline of the whole shell. Specimen identified by Dr. Dall. Rare; one specimen from upper San Pedro series of San Pedro, which is figured, and is now in the collection of Delos Arnold. Living. — Central America (Carpenler). Pleistocene. — San Pedro (Arnold). 179. Drillia renaudi, sp. nov. Platk VIII, Fig. 5. Shell small, fusiform, turreted; apex blunt; whorls eight, sharply angular, with angle about two-fifths distance from anterior margin of whorl; upper and lower surfaces flat; about fifteen oblique nodes ornament the angle and extend down on the lower portion of the whorl, becoming obsolete before reaching the suture; nodes obsolete on body-whorl; suture deeply impressed, distinct; aperture short, elliptical, oblique; posterior sinus broad, shallow; anterior sinus long, straight; columella incrusted within; body-whorl angular, ventricose, much produced and narrow below, smooth, except for very faint incremental lines. Dimensions. — Long. 15.8 mm.; lat. 6 mm.; body-whorl 9 mm.; aperture, including canal, 7 mm.; canal 2 mm.; defl. 35 degrees. Different in shape from any other member of this genus found in these deposits. Distinguishable by the smooth, ventricose body-whorl, sharply angulated whorls, nodose angle, and long canal. This species has the long canal of D. perversa, the angular whorls of Leucosyrinx pedroana, and the nodes, though less prominent, of I), torosa. Specimens pronounced a new species by Dr. Dall. Named in honor of Ralph E. Renaud, who has prepared many of the drawings which illustrate this paper. Rare; one specimen from Pliocene and one (type) from lower San Pedro series of Deadman Island. The specimen figured is the type, which is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Pliocene. — San Pedro (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 209 i8o. Drillia torosa Carpenter. Drillia torosa Cpr., Brit. Assn. Rept., 1863, p. 657;Jour. de Conch., 3id Ser., Vol. XV, 1865, p. 145. Tryon, Man. Conch., Vol. VI, p. 183, Pi. XIV, fig. 93, 1884. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 239. Keep, West Coast Shells, p. 56, fig. 59, 1892. William- son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 298. Shell elongated; spire elevated; apex acute; whorls eight, angulated near middle, with row of about nine nodes, transversely elongated, on angle; the upper portion of whorl flat to concave; anterior half of whorl spirally striated; incremental lines visible, oblique, and on upper part of whorl, concave anteriorly; suture impressed, distinct; lower portion of body- whorl and columella spirally striated; aperture elliptical; outer lip thin and arcuate anteriorly; inner lip and columella slightly incrusted; posterior sinus shallow; anterior sinus short, straight. Dimensions. — Long. 25 mm.; lat. 8 mm.; body-whorl 14.5 mm.; aperture, including canal 9.5 mm.; defl. 22 degrees. Distinguishable by the nodose whorls. The relative length of canal varies somewhat in thi.s species, as does also the prominence of the nodes. Found in the Pliocene at Deadraan Island and Timm's Point; in the lower San Pedro series at Deadman Island and San Pedro; and in the upper San Pedro series at Deadman Island, San Pedro, Los Cerritos, and Crawfish George's. Most common in the lower formations. Living. — Santa Cruz to Santa Barbara (Cooper): San Pedro (Williamson). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). Pliocene. — San Pedro (Arnold). Genus Bela Gray. Shell oval, fusiform, thin; spire produced; canal short; sinus small, near the suture; columella flattened; operculum pointed at both ends. Pleurotoma turricula Montf. is a characteristic species. 181. Bela fidicula Goidd. Plate VII, Fig. 10. Fusus Jidicuia Gi^u., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1849, p. 142; Wilkes' Expl. Exped., Vol. XII, p. 233, fig. 284, 1852. Be/a fidicula Gi^Y)., CpR., Brit. Assn. Rept., 1863, p. 658. Tryon, Man. Conch., Vol. VI, p. 222, PI. XXXII, fig. 17, 1884. Shell small, thin, turreted, short, fusiform; whorls seven, angular, forming a broad shoulder at the suture; surface sculptured with delicate, regular, obtuse, transverse rib-folds, about twenty-four on the last whorl, on the middle of which they disappear, decussated by more crowded, delicate grooves, a little undulating, about eight on the penultimate whorl; suture deeply impressed, distinct; aperture narrow, elliptical; outer lip thin, slightly arcuate; pillar smooth interiorly, spirally striate externally; canal short. Dimensions. — Long. 10 mm.; lat. 4.1 mm.; body-whorl 6.8 mm.; aperture 5 mm.; defl. 30 degrees. Found in Pliocene at Deadman Island, lower San Pedro series at Deadman Island, and upper San Pedro series at Crawfish George's. Found also in the Pleistocene ( 27 ) March 14, 1903. 210 CALIFORNIA ACADEMY OF SCIENCES. in bluff west of bath-house, Santa Barbara, and at old irrigating dittdi, Ventura. The specimen figured is from the lower San Pedro series at Deadman Island, and i.s now in the collection of Delos Arnold. Living. — Puget Sound (Carpenter). Pleistocene. — San Pedro; Santa Barbara; Ventura (Arnold). Pliocene. — San Pedro (Arnold). 182. Bela sanctce-monicae, sp. nov. Plate VIII, Fig. 14. Shell small, broadly fusiform; spire elevated; apex subacute; whorls five, convex, slightly angular above, with about sixteen prominent, rounded ribs, which extend from suture to suture; surface sculptured with spiral sulcations; suture deeply impressed, distinct; aperture slightly oblique, subelliptical; canal short; body-whorl ventricose, lacking transverse sculpture on lower portion; pillar smooth. Dimensio7is. — Long. 12 mm.; lat. 7.5 mm.; body-whorl S.5 mm.; aperture, including canal, 6.8 mm.; canal i mm.; defl. 50 degrees. Distingui.shable from B.fidicula by much broader form, fewer and less sharply angular whorls, and more ventricose body-whorl, and less elevated spire. The type specimen was examined by Dr. Dall, who pronounced it a new species. Type from lower San Pedro series (Pleistocene) at Port Los Angeles, near Santa Monica. Five specimens of the same species, with slightly more angulated whorls, were found in the lower San Pedro series of Deadman Island. The specimen figured is the type, which is now in the United States National Museum. Pleistocene. — San Pedro; Port Los Angeles (Arnold). Genus Mangilia (Leach) Bisso. The present genus includes all P leiirotomidce without opercula. Subgenus Clathurella Carpenter. Shell fusiform or turriculated; columella lip without callosity, except a small posterior tooth; no operculum; the cancellated surface, more ventricose form, and more evident canal, distinguish it from Mangilia; the emargination of the outer lip from C/avalit/a; the texture and sculpture of the surface from Bela and Daphnella. Pleurotoma luLenris Blainv. is a characteristic species. 1.83. Mangilia (Clathurella) conradiana Gahb. ClathiDclla conradiana Gabb, Pal. Cal., Vol. II, p. 7, PI. I, fig. 12, 1869. CooPER, 7lh Ann. Rept. Cal. St. Min., 1888, p. 235. Shell small, robust, broadly fusiform; spire high, whorls seven, the first smooth and round, the remainder angulated, concave above, convex below; surface ornamented by ten or twelve rounded transverse ribs, crossed by square elevated ribs, with sometimes smaller ones interposed; on the upper ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OP SAN PEDRO. 211 or concave part of whorl are several fine, revolving lines; suture deeply impressed, distinct; aperture long, narrow; posterior sinus near suture deep, prominent; anterior sinus short, recurved; outer lip arcuate; pillar straight, spirally striate. Dimensions. — Long. 11.5 mm.; lat. 4.5 mm.; body-whorl 6.9 mm.; aperture 5.5 mm.; defl. 35 degrees. X)istingiiisliable by deep posterior sinus from other members of the same family. (Originally tiescribecl from Pleistocene specimen.) Pronounced as "near C. canjieldii Dall," by Dr. Dall. Rather common in the Pliocene and lower San Pedro series of Deadman Island; rare in the lower San Pedro series and upper San Pedro series of San Pedro. Found in the Pliocene at Packard's Hill; and in the Pleistocene at the bath-house, Santa Barbara. Living. — San Pedro (Raymond). Pleistocene. — Santa Barbara (Cooper): San Pedro; Santa Barbara (Arnold). Pliocene. — San Pedro; Santa Barbara (Arnold): San Diego well (Dall). Subgenus Cythara Schumacher. Shell fusiform, polished, longitudinally ribbed; aperlure linear, truncated in front, slightly notched behind; outer lip margined, denticulated within; inner lip frequently finely striated. Pleurotoma stromboides Reeve is a characteristic species. 184. Mangilia (Cythara) branneri, sp. nov. Plate IX, Fig. 10. Shell small, fusiform; spire elevated; apex rounded; whorls six; slightly convex, with six sharp, slighdy oblique, transverse ribs arranged in slightly twisted lines radiating from the apex; suture impressed, distinct; aperture narrow, truncated in front, slightly notched behind; outer lip margined; inner lip smooth. Dimensions. — Long. 10 mm.; lat. 4 mm.; body-whorl 6 mm.; aperture 4.5 mm.; defl. 27 degrees. Distinguishable by the few longitudinally connected, sharp, radiating ridges. Pronounced by Dr. Dall as probably being new. Named in honor of Dr. John C. Branner, Professor of Geology in Leland Stanford Jr. University. Rather common in lower San Pedro series of Deadman Island. Found also in the Pleistocene at bath-house, Santa Barbara. The specimen figured is the type, which is from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro; Santa Barbara (Arnold). Subgenus Mangilia Risso, s. s. Fusiform, mostly longitudinally ribbed, spire elongated, turriculated, acuminated; canal short, more or less truncated; columella smooth; sinus near the suture. No operculum. Pleurotoma ponderosa Reeve is a characteristic species. 212 CALIFORNIA ACADEMY OF SCIENCES. 185. Mangilia angulata Carpenter. Plate VII, Fig. 9. Mangilia angulata CpR., Brit. Assn. Rept., 1863, p. 658; Ann. & Mag. Nat. Hist., 3rd Ser. , Vol. XV, 1865, p. 395. Keep, West Coast Shells, p. 55, 1892. Cooper, Bull. No. 4, Cal. St. Min. Bureau, 1894, Part 3, p. 27. Shell small, turreted, elongate- fusiform; apex acute; whorls six, broad and angular, angle being slightly posterior to middle; sculpture consists of ten prominent, rather sharp, transverse ridges which reach maximum prominence on angle of whorl; suture deeply impressed, distinct, aperture oblique, narrow, elliptical, drawn out anteriorly into a short, narrow canal; outer lip thin; simple, arcuate; inner lip smooth. Dimensions. — Long. 8 mm.; lat. 3.2 mm.; body- whorl 5 mm.; aperture 4 mm.; defl. 33 degrees. Some of the shells show a very faint spiral sculpture. Distinguishable by broad form and simple transverse sculpture. Specimens identified by Dr. Dall. Many sj^ecimens of this species in the State museum collection of fossils at Berkeley are labeled "il/. variegata." Rather common in the lower San Pedro series of Deadman Island and San Pedro; rare in the upper San Pedro series at Crawfish George's and Los Cerritos. Found also in the Pleistocene at bath-house, Santa Barbara; Barlow's ranch, A^en- tura, and at Spanish Bight and Pacific Beach, San Diego. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Puget Sound to Santa Barbara (Carpenter). Pleistocene. — San Pedro (Arnold): San Joaquin Bay, Orange County (Bowers): Santa Barbara; Ventura; San Diego (Arnold). 186. Mangilia hooveri, sp. nov. Plate IX, Fig. 5. Shell small, elongate-fusiform, solid; spire elevated; apex mammilliform; whorls six, only slightly convex, with about ten low, rounded, slightly oblique, transverse ridges; the first whorl is smooth, while the next three are more convex than the lower ones, and have traces of spiral sculp- ture; body-whorl with sculpture nearly obsolete; aperture elliptical, tapering to a very short canal anteriorly; outer lip arcuate, thin; pillar quite long and straight. Dimensions. — Long. 10.9 mm.; lat. 3 mm.; body-whorl 6 mm.; aperture 4 mm.; defl. 20 degrees. Distinguishable by the slender form, nearly flat whorls, and the broad, low, transverse ridges. The body-whorl resembles that of a small, elongate-j^illared DriUia. Pronounced new by Dr. Dall. Named in honor of Mr. T. J. Hoover of Stanford University, California. Type from upper San Pedro series of San Pedro; rare. The specimen figured is the type, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 213 187. Mangilia interfossa var. pedroana, var. nov. Plate VI, Fig. 3. Majigilia iti/er/ossa Cpr., Brit. Assn. Rept., 1863, p. 658; Ann. & Mag. Nat. Hist., 3d Ser., Vol. XV., 1865, p. 29. Daphnella mterfossa Cpr., Tryon, Man. Conch., Vol. VI, p. 310, PI. XXII, fig. 11, 1884. Shell small, turreted, elongate-fusiform; apex acuminate; whorls six, convex, ornamented with about sixteen rounded, slightly oblique, transverse ridges and four to six sharp, raised, spiral lines in the interspaces; suture deeply impressed; aperture narrow, slightly oblique, elliptical; outer lip thin, simple; inner lip smooth. Dimensions. — Long. 7.5 mm.; lat. 2.5 mm.; body-whorl 4.1 mm.; aperture 2.8 mm.; defl. 30 degrees. Distinguishable from M. inter lirnta by broader form, more convex whorls, and more numerous lines of sculpture. Specimens pronounced new variety of M. inter- fossa by Dr. Dall. Rare in lower San Pedro series at Deadraan Island; and in upper San Pedro series at Crawfish George's. Found also in the Pleistocene at bath-house, Santa Barbara. The specimen figured is the type, which is from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro; Santa Barbara (Arnold). 188. Mangilia interlirata Stearns. Plate VI, Fig. 15. Mangilia interlirata BTTS.Av.iiS, Proc. Cal. Acad. Sci., Vol. IV, 1872, p. 226, PI. I, fig. 10. Tryon, Man. Conch., Vol. VI, p. 249, PI. XXII, fig. 56, 1884. Shell small, elongate, fusiform; spire much elevated; apex acute; whorls six, slightly con- vex, ornamented by nine or ten slightly oblique, rather narrow, transverse ridges; spiral sculpture consists of three or four sharp raised lines, which extend to base of body-whorl; suture impressed, distinct; aperture narrow, elliptical; outer lip thin, simple; inner lip simple; canal simple. Dimensions. — Long. 8.8 mm.; lat. 3 mm.; body-whorl, 4.9 mm.; aperture, 3 mm.; defl. 25 degrees. Distinguishable from M. interfossa var. 'pedroana by its slenderer outline, fewer transverse and spiral ridges, and flatter whorls; distinguished from others of the genus by the prominence of its spiral lines. Specimens identified by Dr. Dall. Rare in lower San Pedro series at Deadman Island, and in the upper San Pedro series at Los Cerritos. The specimen figured is from the Lower San Pedro series at Deadraan Island, and is now in the collection of Delos Arnold. Living. — West Coast. Pleistocene. — San Pedro (Arnold). 189. Mangilia oldroydi, sp. nov. Plate VI, Fig. 16. Shell small, turreted, elongate-fusiform; apex acuminate; whorls seven, convex, rather shouldered above, and crossed by sixteen slightly oblique rounded ridges; transverse ridges become 214 CALIFORNIA ACADEMY OF SCIENCES. obsolete on lower hall" of body-vvhorl; spiral sculpture consists of three or four fine raised lines on lower portion of whorl and several microscopic lines on upper portion; the spiral sculpture is more prominent on the body-whorl; suture deeply impressed; aperture narrow p)'riform, drawn out on anterior end to a long, narrow, recurved canal; outer lip arcuate, thin, simple; inner lip smooth. Dimensions. — Long. 16 mm.; lat. 6 mm.; body-whorl 10 mm.; aperture 8 mm.; defl. 38 degrees. The largest and finest of the Pleistocene MnngUve. Distinguishable by its large size, rounded ridges, faint shouldered appearance of the whorls, and long, recurved canal. " Different from any of the species in the Smithsonian collec- tion " (Dall). Rare in lower San Pedro series of Deadman Island; one specimen (ty[)e) collected by Mrs. Oldroyd, which is figured, and is now in her collection. Pleistocene. — San Pedro (Oldroyd). 190. Mangilia painei, sp. nov. Plate VIII, Fu:. 1. Shell small, elongate-fusiform; spire elevated; apex rounded; whorls seven, evenly convex, with about eleven slightly transverse, rounded ribs, which become obsolete at the sutures; spiral sculpture obsolete; aperture narrow, elliptical, narrowing anteriorly to canal; canal truncate in front; posterior sinus small; outer lip arcuate, thin, with faint ridge on interior; suture deeply impressed ; pillar long, smooth within, obsolete sculpture without. Dimensions. — Long. 12 mm.; lat. 4.2 mm.; body-vvhorl S mm.; aperture, including canal, 6.1 mm.; canal 1.5 mm.; defl. 32 degrees. Distinguishable by slender form, evenly convex whorls, prominent transverse ribs, and obsolete spiral sculpture; canal also longer than in most species. Resembles 7)/. oldroydi in outline, but has no spiral sculpture or angulated whorls. Pronounced a new species by Dr. Dall. Named in honor of Miss Winifred Mabel Paine of Red- lands, California, who has drawn many of the figures illustrating this paper. Not uncommon in the lower San Pedro series of Deadman Island. The specimen figured is the type, which is from the lower San Pedro series of Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). 191. Mangilia sculpturata Ball. Plate VI, Pig. 17. Be/a sculpturata Dall, Proc. U. S. Nat. Mus., Vol. IX, 1887, p. 299, PI. IV, fig. 7. Shell small, turreted, elongate- fusiform; apex acute; whorls seven, sharply angulated, with flat, sloping surfaces both above and below angle; sculpture consists of eight or nine sharp transverse ridges, and two or three sharp spiral lines on lower portion; aperture very deeply impressed, giving tabulate appearance to whorls; aperture long, narrow, and drawn out into a long, narrow canal at anterior end; outer lip thin, simple; inner lip smooth; spiral sculpture extends to base of pillar. Dimensions. — Long. 10.5 mm.; lat. 3 mm.; body-whorl 6 mm.; aperture 4 mm.; defl. 23 degrees. ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 215 A slender, deeply sutured form, with a comparatively long canal; these characteristics distinguishing it from others of the genus. Specimen identified by Dr. Dall. ' • Rare in Pliocene and lower San Pedro series of Deadman Island; one specimen from each horizon. The specimen figured is from the Pliocene of Dead- man Island, and is now in the collection of Delos Arnold. Living. — West Coast. Pleistocene. — San Pedro (Arnold). Pliocene. — San Pedro (Arnold). 192. Mangilia striosa 0. B. Adams. Pl.ATK IX, FiC. .s. Mangilia striosa C. B. Ads., Ann. N. Y. Lye. Nat. Hist., Vol. V, 1852, p. 147. Tryon, Man. Conch., Vol. VI, p. 249, PL XXXIV, fig. 96, 1884. Williamson, Proc. U. S. Nat. Mus., Vol. XV, p. 208, 1892. Shell small, elongate-fusiform; spire much elevated; ape.x acute; whorls six, subangular, with numerous fine, slightly wavy transverse ridges, which become obsolete at the sutures; spiral sculpture nearly obsolete; suture very deeply depressed, giving a rather frail appearance to the spires; aperture narrow, elliptical, tapering anteriorly to a short, truncated canal; posterior sinus small; outer lip thin, simple, arcuate; columella smooth; straight on anterior portion. Dimensions. — Long. 9.2 mm.; lat. 3 mm.; body-whorl 5.2 mm.; aperture 4 mm.; defl. 22 degrees. This species is distinguishable by its numerous fine, transverse ridges, deep suture, subangular whorls, and slender form. Resembles M. sciilpttiraia somewhat in outline, but has less angular whorls and more numerous, finer ribs. Distinguishable from 2/. oldrnijdi by the angle being nearer the middle of the whorl, the ridges being finer, the pillar .shorter, and the suture deeper. Specimens identified by Dr. Dall. Rare in upper San Pedro series of San Pedro and Los Cerritos. Found also in Pleistocene at Spanish Bight, San Diego. The specimen figured is from the upper San Pedro series at Los Cerritos, and is now in the collection of Delos Arnold. Living. — Panama (Carpenter): San Pedro (Williamson). Pleistocene. — San Pedro; San Diego (Arnold). Subgenus Taranis Jeffreys. Shell minute, cancellated; whorls angulated, slightly exserted at base; aperture pyriform; outer lip thin, simple; sinus obsolete; canal short. l^arnnis morchii Malm, is a characteristic species. 193. Mangilia (Taranis) strongi, sp. nov. Plate IX, Fig. 7. Shell small, elongated; spire elevated; apex mammilliform; whorls six, angulated near middle, upper surface concave, lower surface convex; two strong spiral ridges, one on angle, the 216 CALIFORNIA ACADEMY OF SCIENCES. other in middle of lower portion of whorl; incremental lines visible; suture impressed, distinct; aperture subovate, oblique; outer lip thin, slightly arcuate anteriorly; inner lip smooth; posterior sinus broad, very shallow; anterior sinus short; columella short, distinct. Dimensions. — Long. 12 mm.; lat. 5.5 mm.; body-whorl 7 mm.; aperture 5 mm.; defl. 38 degrees. Distinguishable from others of the same family by the two strong, revolving ridges. Named in honor of A. M. Strong. Specimens pronounced new species by Dr. Dall. Rare in the lower San Pedro series of San Pedro and Deadraan Island; found also in the Pliocene of Deadman Island, and in the upper San Pedro series at Craw- fish George's. The specimen figured is the type, which is from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Pliocene. — Santa Monica; San Pedro (Arnold). Subgenus Spirotropsis Sars. Shell elongate, turreted, spire produced; the obtuse apex mammilliform; whorls numerous, carinated in the middle; aperture narrow, oblique, with a short canal; sinus deep; remote from suture. Plmrotoma carinatn Phil, is a characteristic species. 194. Pleurotoma (Spirotropsis) smithi, sp. nov. Platk VI, Fig. 13. Shell elongate, turreted, slender; spire elevated; apex obtuse, mammilliform; whorls ten, convex, with a slight tendency toward angulation on the lower third of the whorl, and abruptly terminated at the posterior margin; suture very deeply impressed, distinct; sculpture consists simply of oblique, incremental lines, which are quite deeply angulated convexly, posteriorly just a little above the middle of the whorl; aperture narrow, oblique; outer lip thin, arcuate anteriorly; inner lip smooth and incrusted; posterior sinus deep and remote from suture; canal narrow, slightly recurved, over one-third of the aperture. Dimensio7is. — Long. 35 mm.; lat. 11 mm.; body-whorl 8.5 mm.; aperture 13 mm.; defl. 19 degrees. A long, slender species, slightly resembling the sinistral P. perversa in general outline, but easily distinguishable from that species and also from all the other members of this family. Some of the shells are a little more depressed than the tyjie. Specimens identified by Dr. Dall as being a new species. Not uncommon in tiie lower San Pedro series and Pliocene of Deadman Island. The specimen figured is the type, which is from the Pliocene of Deadman Island, and is now in the United States National Museum. Living. — (Locality not mentioned) (Dall). Pleistocene. — San Pedro (Arnold). Pliocene. — San Pedro (Arnold). AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 217 Family LIII. CANCELLARIID^. Genus Cancellaria Lamarck. Subgenus Cancellaria s. s. Shell oval, cancellated; last whorl ventricose; aperture oblong, canaliculated in front; canal short, sometimes recurved; columella with several large oblique plications. Type, Cancellaria cancellata Linn. 195. Cancellaria cooperi Gahh. Plate VII, Fig. 8. Cancellaria {Narona) cooperi Ga.'r^, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 186. Cancellaria cooperi Gabb, Tryon, Man. Conch., Vol. VII, p. 76, PI. IV, fig. 66, 1885. William- son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 211, PI. XXII, fig. 2. Shell fusiform; spire elevated, about one-third length of shell; apex subacute; whorls six to seven, angulated, concave above, convex below; lower portion of whorl with ten to fourteen promi- nent, rounded, slightly oblique ribs which end in tubercles on angle; lower part of whorl ornamented with close-set spiral ridges, alternating in prominence; ridges on upper part of whorl less prominent; body-whorl ventricose and crossed by raised incremental lines; suture appressed, wavy, distinct; aperture seniielliptical; outer lip not thickened, denticulated; inner lip heavily incrusted, and with two sharp, oblique pHcations on lower part; columella slightly twisted, rough; canal short. Dimensions. — Long. 80 mm.; lat. 35 mm.; body-whorl 56 mm.; aperture, including canal, 35.5 mm.; defl. 40 degrees. Rare in the upper San Pedro series of San Pedro; five specimens found. Mrs. Oldroyd has a fine living specimen of this species which was hauled up in the fishermen's nets at San Pedro. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Monterey to San Diego (Cooper): San Pedro (Oldroyd). Pleistocene. — San Pedro (Arnold). 196. Cancellaria crawfordiana BaU. Cancellaria crawfordiana Dall, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 182, PL VI, fig. i. Shell small, fusiform; spire elevated; whorls five or six, acutely angulated above near margin; upper portion flat, forming revolving table; lower portion evenly convex; sculpture very prominent, cancellated, consisting of about twenty-five nearly straight, equidistant, transverse ribs and about ten equidistant spiral ridges of equal prominence with the transverse ones; incremental lines visible between transverse ribs; suture impressed, very distinct; aperture semielHptical; outer lip slightly thickened and faintly denticulate; inner lip not incrusted; columella with two prominent plications on the inner side; canal short and broad. Dimensions. — Long. 37 mm.; lat. 16 mm.; body-whorl 24.5 mm.; aperture, including canal, 17.5 mm.; defl. 38 degrees. Resembles C. coo])eri in shape, but is distinguishable by the prominent cancel- lated sculpture. ( 28 ) March 17, 1903. 218 CALIFORNIA ACADEMY OF SCIENCES. Rare in upper San Pedro series of San Pedro; one specimen found. Living. — Drake's Bay to San Diego, 20 to 30 fathoms (Dall): San Pedro (Raymond). Pleistocene. — San Pedro (Arnold). 197. Cancellaria tritonidea Gabb. Plate VII, Fig. 5. Cancellaria irilonidea Gabb, Pal. Cal, Vol. II, pp. ii, 79, PI. II, fig. 18, i86g. Cooper, 7th Ann, Rept. Cal. St. Min., 1888, p. 231. Dall, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 1S3. Shell large, robust-fusiform; spire elevated, subacute; whorls six, first generally decollated, angulated; upper part of first three and one-half revolutions convex; upper part of lower whorls concave; lower part of all whorls, except body-whorl, generally covered with a lamellar incrus- tation; ten prominent sharp nodes on angle of whorl; whorls ornamented with numerous promi- nent, squarish, spiral ridges between which are less prominent raised lines; incremental lines visible, and some of them which pass through the nodes have the prominence of weak varices; suture appressed, wavy, distinct; aperture subovate; outer lip not thickened; inner lip incrusted; columella rough, twisted, widened, with two prominent plications on the inner side; canal short, wide. Dimensions. — Long. 90 mm.; lat. 60 mm.; body-whorl 70 mm.; aperture, not including canal 50 mm.; defl. 75 degrees. The shell figured and desci'ibed in this paper is the largest and most nearly perfect one yet found in this locality. Gabb's tyj^e specimen was beach worn and not as well preserved as the one described above, which accounts for the lack of the sharp nodes and more rounded outline of his shell. A specimen in this collection labeled "Cancellaria vetusta Gabb, Pliocene, Ventura" by Dr. Bowers, is of the same species. Whether Bowers' specimen came from the Pliocene or Pleistocene is a matter of doubt. Dr. Dall pronounced C. tritonidea near to O.cassldiformis Sowerby, and it mav be one form of this latter variable species. The young shells of this species are quite variable in regard to the promi- nence of the nodes, amount of angulation of the whorls, and the shape of the aper- ture. Any one not possessing a series showing the connection between the two extremes might think them different species. C. vetusta is probably a precursor of, if not identical with, C. tritonidea. Rather rare in the upper San Pedro series of San Pedro. Found also in the Pleistocene at Barlow's ranch and at old irrigating ditch, Ventura. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collec- tion of Delos Arnold. Pleistocene. — Coyote Creek, Ventura County; San Pedro (Cooper): San Pedro; Ventura (Arnold). AKNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF 8AN PEDRO. 219 Genus Admete Mailer. Shell oval, thin, diaphanous, covered by a thin epidermis; spire sharp; last whorl ventricose; aperture oval, feebly channeled in front, columella arcuated, obliquely truncated, with rudimentary plications; outer lip sharp. Admete viridula Fabr. is a characteristic species. 198. Admete gracilior Carpenter. Plate VII, Fig. 4. Cancellaria gracilior CpR., Pal. Cal., Vol. II, p. 50, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 23. Shell small, ovate, thin; spire elevated, subacute; whorls six, rounded to subangular, crossed by numerous prominent, rounded ridges which reach their maximum prominence on the angle of the whorl; these ridges become nearly obsolete on the anterior part of the body-whorl; spiral sculpture consists of numerous fine ridges and furrows; suture deeply depressed, giving shouldered appear- ance to whorls; aperture ovate; outer lip thin, smooth; inner lip only slightly incrusted; columella obliquely truncated, and having two plications on inner side; slight umbilical slit; no canal. Dimensions. — Long, 11 mm.; lat. 6.3 mm.; body-whorl 7.5 mm.; aperture 5.5 mm.; defl. 50 degrees. A unique form, looking something like a small Fusus robustuti with the canal gone. It is quite a variable species, one specimen showing a narrower spire and fewer, but more prominent ribs than the type, while still another showed more rounded whorls and less prominent ridges. Found in the lower San Pedro series at Deadman Island. Also obtained from the Pleistocene at the bath-house, Santa Barbara; and at Port Los Angeles, near Santa Monica. The specimen figured is from the lower San Pedro series at Dead- man Island, and is now in the United States National Museum. Pleistocene.- — San Pedro (Oldroyd; Arnold): Santa Barbara (Carpenter; Arnold): Santa Monica (Arnold). Family LIV. OLIVID^. Genus Olivella Sivuinson. Shell small, polished; spire produced, acute; suture canaliculated; aperture narrow behind; enlarged anteriorly; columella plicated in front, callous posteriorly. Olivella undatella is a characteristic species. 199. Olivella biplicata Suiverbtj. Olivella biplicata Sby., Tank. Cat., App., p. 33, 1825. Cpr , Brit. Assn. Rept., 1863, p. 661. H. & A. Adams, Gen. Rec. Moll, p. 146. Gabb, Pal. Cal., Vol. II, p. 75, 1869. Tryon, Man. Conch., Vol. V, p. 87, PI. XXXIV, fig. 58, 1883. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 255. Keep, West Coast Shells, p. 40, fig. 20, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 212 (and varieties). 220 CALIFORNIA ACADEMY OF SCIENCES Shell small, subcylindrical; spire only slightly elevated; apex subacute; whorls five or six, flat, smooth, except for very fine incremental lines; suture appressed, very distinct; body-whorl convex, but nearly flat near outer lip; aperture elongate-triangular; outer lip thin, nearly straight; inner lip thickly incrusted, the incrustation forming quite a ridge; columella completely incrusted around lower portion, two prominent plications. Dime)isions.— "Long. 17.7 mm.; lat. 9.6 mm.; body-whorl 15.7.; aperture 13. i mm.; apical angle 90 degrees. This species differs from 0. 2:>edroana in size and comparative width, and from 0. intorta in having two plaits, a greater deflection, and in being much larger. Common in the lower and upper San Pedro series, and Pliocene of the San Pedro region. Found also in the Pleistocene at Barlow's ranch and the old irri- gating ditch, Ventura; at the bath-house, Santa Barbara, and at Spanish Bight and Pacific Beach, San Diego. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa Barbara; Ventura; San Diego (Arnold). Pliocene. — Seven Mile House; Twelve Mile House; Kirker's Pass; San Diego well (Cooper): San Pedro (Arnold). 200. Olivella intorta Carpenter. Olivella ijitorta Cpr., Proc. Zool. Soc, 1856, p. 207. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 255. Keep, West Coast Shells, p. 42, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 212, PI. XIX, fig. 9. Shell small, subovate; spire elevated, solid; whorls five, flat, smooth; suture appressed, very distinct; body-whorl ventricose, smooth; aperture long, narrow, widening anteriorly; outer lip thin; inner lip incrusted, incrustation thick, forming callus on body of middle whorl near aperture; columella with smooth incrustation over lower portion, and one prominent, sharp plait on lower side. Dimensions. — Long. 11. 7 mm.; lat. 6 mm.; body-whorl 9.7 mm.; aperture 7.2 mm.; defl. 60 degrees. Distinguishable from 0. pedroana by breadth, less elevated spire, greater deflection, and larger callus on upper part of inner lip; distinguishable from 0. hipllcata by single plait on columella, less deflection and smaller size. Quite common in the Pliocene and Pleistocene of the San Pedro region; rare in upper San Pedro series at Los Cerritos. Found in the Pleistocene at Twenty-sixth Street and Pacific Beach, San Diego; and at Barlow's ranch and the old irrigating ditch, Ventura. Living. — Santa Cruz to Lower California (Dall). Pleistocene. — San Pedro; San Diego (Cooper): San Pedro; Ventura; San Diego (Arnold). Pliocene. — San Diego well (Dall). AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 221 201. Olivella pedroana Conrad. Strepho7ia pedroana Con., Pac. R. R. Rept., Vol. V, p. 327, PI. VI, fig. 51, 1854. Olivella bwtica Cpr., Brit. Assn. Rept., 1863, p. 661. Gabb, Pal. Cal., Vol. II, p. 75, 1869. Tryon, Man. Conch., p. 71, PI. XVII, figs. 28, 31, 34, 1883. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 255. Keep, West Coast Shells, p. 42, fig. 21, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 212, PI. XIX, fig. 7. Shell small, elongate; spire elevated; apex acute; whorls five, flat, smooth; suture appressed, very distinct; aperture elongate-triangular; outer lip thin; inner lip callous; lower part of columella incrusted; columellar plication divided by median groove. Dimensions. — Long. 12.9 mm.; lat. 5 mm.; body-whorl 9.4 mm.; aperture 7.2 mm.; defl. 40 degrees. Distinguishable from 0. intorta by double columellar plication, smaller callus, slenderer form, sharper apex and straighter outer lip; distinguishable from 0. hipli- cata by slenderer form, smaller size, and more elevated spire. Common in upper San Pedro series of Los Cerritos; rare in upper and lower Ban Pedro series, and Pliocene of San Pedro and vicinity. Found also in the Pleistocene at Spanish Bight and Pacific Beach, San Diego, and at Barlow's ranch, Ventura. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura; San Diego (Arnold). Pliocene. — Seven Mile Beach; Twelve Mile House; Kirker's Pass; San Diego well (Cooper). Family LV. MARGINELLID.E. Genus Marginalia Lamarck. Shell ovately oblong to subcylindrical, smooth, polished, sometimes longitudinally ribbed; spire short, conical, or concealed; aperture narrow, elongated, obtuse or truncated in fi'ont; columella plicate; outer lip with a thick marginal varix, its inner margin smooth or crenulated. Marginella glohella Linn, is a characteristic species. 202. Marginella jewettii Carpenter. Margi7iella jewetiii Cfk., Proc. Zool. Soc, 1S56, p. 207; Brit. Assn. Rept., 1S63, p. 661. Trvon, Man. Conch., Vol. V, p. 43, PI. XII, fig. 57, 1883. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 249. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part i, 1890, p. 57. Keep, West Coast Shells, p. 43, fig. 23, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 212, PL XIX, fig. 6. Shell small, smooth, ovate-oblong; spire barely visible; aperture not extending fijll length of shell, narrow, elongated, obliquely truncated in front; outer lip thickened with marginal varix, its inner side smooth; columella with three prominent plications near anterior end, and lesser ones above. Dimensions.- — Long. 5 mm.; lat. 3 mm.; aperture 4.7 mm. Specimens identified by Dr. Dall. 222 CALIFOllNIA ACADEMY OF SCIENCES. Fouud in the lower San Pedro series at Deadraan Island and San Pedro, and iu the upper San Pedro series at Crawfish George's, San Pedro, and Deadman Island. Living. — Monterey to San Pedro (Dall). Pleistocene. — San Pedro (Cooper; Arnold). Section Volvarina Hinds. Shell small, pyriform, polished; spire elevated, but concealed by enamel; aperture not extending full length of shell; outer lip thin, with incurving flange; columella with sharp plaits. 203. Marginalia (Volvarina) varia Sowerby. Plate IV, Fuj. 9. Volvarina varia Sby. , Cpr. , Brit. Assn. Rept., 1863, p. 661. Keep, West Coast Shells, p. 43, 1892. Shell small, pyriform, smooth; spire elevated slightly, but concealed by enamel of surface; aperture not extending full length of body- whorl, narrow posteriorly, widening gradually anteriorly; outer lip thin, with a flange curved inward; columella with four sharp plaits. Dimensions. — Long. 9 mm.; lat. 5 mm.; aperture 8 mm. Specimens identified by Dr. Dall. Found in all of the lower and upper San Pedro series localities in the vicinity of San Pedro. Found also in the Pleistocene at Twenty-sixth Street, San Diego. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Santa Barbara to San Diego (Cooper): Cape St. Lucas; West Indies (Carpenter). Pleistocene. — San Pedro; San Diego (Arnold). Family LVI. MITRID.E. Genus Mitra Lamarck. Shell fusiform, thick; spire elevated; aperture small, narrow, notched in front; columella transversely, somewhat obliquely, plicate; outer lip thick, smooth within, without external varices. Type, Ultra episcopalis Lam. 204. Mitra maura Swainson. Mitra niauraSvjhi^., Proc. Zool. Soc, p. 193, 1835. Cpr., Brit. Assn. Rept., 1S63, p. 661. Trvon, Man. Conch., Vol. IV, p. 121, PI. XXXVI, fig. 67, 1882. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257. Keep, West Coast Shells, p. 42, fig. 22, 1892. William- son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 211. Shell mitre-shaped; spire elevated; apex subacute; whorls five or six, only slightly convex, each appressed against antecedent whorl, forming a distinct suture; surface smooth, except for incremental lines; aperture long, narrow; outer lip thickened; inner lip not incrusted; columella with four distinct plaits, which increase in prominence posteriorly. Dimensions. — Long. 56 mm.; lat. 18.5 mm.; body-whorl 37 mm.; aperture 25 mm.; defl. 30 degrees. ARNOLD — THE PALEONTOLOGY AND STHATIGRAPHY OF SAN PEDRO. 223 Found in the lower San Pedro series at San Pedro, and in the up[)er San Pedro series at Deadman Island, San Pedro and Crawfish George's. Xm?i^.— Farallon Islands to San Diego; South America (Cooper). Pleistocene. — Santa Barbara to San Diego; San Nicholas Island (Cooper) : San Pedro (Arnold). Pliocene. — San Pedro (Arnold). f Genus Mitromorpha A. Adams. Shell small, elongately fusiform; whorls flattened, with revolving lirae, and sometimes longi- tudinally plicate; aperture narrow; columella straight, slightly transversely Urate; lip acute, smooth within, scarcely sinuated posteriorly. Mitromovplia gracilis Carpenter is a characteristic species. 205. Mitromorpha filosa Carpenter. ? Daplmella filosa CpR., Brit. Assn. Rept., 1863, p. 658. Mitro77iorpha filosa CpR.,* Keep, West Coast vShells, p. 55, 1S92. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 200, PI. XIX, fig. i. Shell small, mitre-shaped; apex rounded; whorls six, flat, ornamented with several sharp, raised, revolving lines; suture impressed, distinct; aperture long, narrow, oblique; outer lip denticu- late interiorly; inner lip smooth; columella spirally lined externally. Ditnensions. — Long. 8 mm.; lat. 3.6 mm.; body-whorl 6 mm.; aperture 5 mm.; defl. 55 degrees. A shell from the Pleistocene shows transverse ridges on first four whorls, but these become obsolete below this. This transversely ridged specimen is intermediate between the typical M. filosa and M. intermedia. M. aspera is jirobably the type of the precursor of the three West Coast species mentioned, then in phylogenetic order would come M. intermedia, specimens like the ridged variety of J\I. filosa, and lastly typical M. filosa. The cancellate upper whorls of all the species except M. filosa show j\J. aspera to be the precursory form. One specimen in lower San Pedro series of San Pedro. Living. — Santa Barbara (Carpenter): San Pedro (Simpson). Pleistocene.- — San Pedro (Arnold). 206. Mitromorpha intermedia, sp. nov. Plate IV, Fig. 10. Shell small, mitre-shaped; apex rounded; whorls six; slightly convex; whorls ornamented with about four equidistant, sharp, raised spiral lines, and numerous rounded, transverse ridges which are most prominent on angle of whorl; ridges are obsolete, or nearly so, on body-whorl; suture quite deeply impressed; aperture long, narrow, oblique; outer lip slightly arcuate anteriorly, smooth interiorly; inner lip smooth; columella spirally lined externally. Dimcnsio7is. — Long. 9.5 mm.; lat. 3.9 mm.; body-whorl 6.5 mm.; aperture 4.5 mm.; defl. 36 degrees. 224 CALIFORNIA. ACADEMY OF SCIENCES. This species occuiiies a position nearly midway between M. filoaa and M. asjiern. It differs from the first in having distinct transverse ridges on the upper whorls, a smooth inner Jip, a slightly slenderer form, and a more impressed suture; and differs from the second in having fewer transverse ridges, which are obsolete, or nearly so, on the body-whorl, a narrower aperture, a slenderer form and more numer- ous and sharper spiral lines. Pronounced a new variety of Jilosa by Dr. Dall. Its characteristics would ally it a little more readily with M. aspera, but it has enough distinctive features to separate it from both. Rare in lower San Pedro series of Deadraan Island. Found in the Pleistocene at the bath-house, Santa Barbara. The specimen figured is the type, which was found in the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Xmn^?.— West Coast (?) (Dall). Pleistocene. — San Pedro; Santa Barbara (Arnold). Family LVII. FASCIOLARIIDiE Subfamily FUSING. Genus Fusus La-march. Shell fusiform; spire long, acuminate, many-whorled; aperture oval, usually striate within; outer lip simple; columella smooth; no umbilicus; canal long and straight. Fusus nicoharicus Lam. is a characteristic species. 207. Fusus barbarensis Trash. Plate IV, Fig. 15. Fiisus barbarensis Trask, Proc. Cal. Acad. Sci., Vol. I, 1855, p. 41. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 240. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 217. Fitsiis corpukntus (not of Conrad, Wilkes' Expl. Exped., Vol. X, p. 728, PI. XX, fig. 4, 1849) Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 26. Fusus dupetithouarsi {non Kiener), Cooper, Bull. No. 4, Cal. St. Mining Bureau, Part 3, 1894, p. 26. Shell of medium size, long, slender, fusiform, rather thin; whorls nine, evenly convex, crossed by about ten rather low, rounded ridges, which fade out toward sutures; body-whorl sometimes lacks these ridges, but in that case it generally has an irregularly, wavy surface ornamented with numerous sharp, raised spiral lines with sometimes smaller lines intercalated; suture deeply appressed; aperture subelliptical; outer lip thin, smooth margin, with prominent, internal spiral lines beginning just pos- terior to margin; inner lip incrusted, sometimes not covering the spiral sculpture of columella; columella long, nearly straight, except for curve backwards, spirally ridged; canal long, narrow, nearly straight. Dimensions. — Long. 60 mm.; lat. 20 mm.; body-whorl 39 mm.; aperture, including canal, 31 mm.; canal 15 mm.; defl. 32 degrees. Distinguishable from F. rohustus and F. rugosus by much slenderer form, longer spire, more clear-cut spiral lines, and longer and straighter canal. This is the oldest AKlSfOLD — THE PALEONTOLOGY AND STllATIGKAPHY OF SAN PEDRO. 225 form found in this locality. There is no doubt about the close relationship of the three species, barbarensis, robustus and rugosus, as the large series of each which the writer has had during the preparation of this paper shows forms nearly, if not quite, filling the gaps between the three types. JF'. barbarensis is probably the precursor of the other two forms, and although it occurs in the later horizons in which the other two sjiecies are the denominating types, still, judging by numbers, this form reached its maximum development in the upper San Pedro series. Specimens identified by Dr. Dall. Common in the Pliocene, rare in the lower San Pedro series of Deadman Island; one or two specimens found at each of Deadman Island, San Pedro, and Crawfish George's in the upper San Pedro series. The specimen figured is from the Pliocene at Deadman Island, and is now in the collection of Delos Arnold. This and several other species have been reported from the "Miocene of Deadman Island." Although the lowest horizon at Deadman Island is Miocene, still all of the fossils reported as occurring in the Miocene at that place come out of a Pliocene stratum which rests unconformably upon the Miocene. Living — San Pedro (Oldroyd; Raymond). Pleistocene. — Santa Barbara (Trask; Cooper): San Pedro (Arnold). Pliocene — San Pedro (Arnold). 208. Fusus luteopictus Ball. Fiisi/s /ufeoprdus Dall, " ' Proc. Cal. Acad. Sci.,' 1877, p. 4." (Author's unauthorized reprint, issued March ig, 1877.) Fiisics ambustus Gld., Cpr., Brit. Assn. Rapt., 1863, p. 664 (pars.); (not of Gould) {fide Dall.) Fusus genicnlus CoNR., Gabb, Pal. Cal., Vol. II, p. 71, 1S69 (pars. syn. exel.) (7?^,? Dall). Fusus avibustus (^LV).,(ZoovEK, Cal. Monterey Shells, Am. Jour. Conch., Vol. VI, p. 70; Geog. Cat., No. 787 (most Californian writers) {fide Dall). Fusus lulcopichis Dall, Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1S92, p. 217, PI. XX, fig. i. Shell small, fusiform; whorls five, convex, crossed by nine rounded ridges which reach their maximum development on the middle of whorl; surface ornamented with three or four prominent spiral lines, with finer ones sometimes intercalated; suture appressed; aperture subovate; outer lip not thickened, with internal spiral lines; inner lip incrusted; columella short; canal very short, narrow. Dimeyisions. — Long. 19 mm.; lat. 10 mm.; body-whorl 13.5 mm.; aperture, including canal, 10 mm.; canal 3 mm.; defl. 38 degrees. Distinguishable by small size and very short canal. Rare in the lower San Pedro series at Deadman Island; common in the upper San Pedro series at Crawfish George's, but rare in the same horizon at San Pedro, Deadman Island and Los Cerritos. Most of the specimens obtained came from Crawfish George's. Living. — Farallon Islands to San Diego (Dall). Pleistocene. — San Pedro (Arnold). (29) March 19, 1903. 226 CALIFORNIA ACADEMY OF SCIENCES. 209. Fusus robustus Trask. Fusus robustus Trask, Proc. Cal. Acad. Sci., Vol. I, 1855, p. 41. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 241. Fusus kobelli {noi of Dall), of Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 240 (in part). Shell of medium size, elongate-fusiform, thick; whorls about si.\, convex, crossed by eight or nine prominent rounded ridges which are most prominent on angle of whorl (these ridges are sometimes obsolete on the anterior part of the body-whorl); spiral sculpture consists of four to six prominent raised lines, with sometimes smaller lines intercalated; suture appressed, deep, distinct; aperture pyriform; outer lip smooth on inner edge, but with numerous spiral ridges further in; inner lip smooth; columella spirally ridged externally; canal rather short, narrow. Dimensiotis. — Long. 34 mm.; lat. 14 mm.; body-whorl 22.5 mm.; aperture, including canal, 17 mm.; canal 5 mm.; defl. 40 degrees. Distinguishable from F. rugosas by smaller size, heavier shell, lack of promi- nent angular appearance of whorls and ridges near posterior suture, less number of wliorls and relatively shorter canal. Upon examining a large series of this species and of F. rugosus the writer has no hesitancy in separating these two forms of Trask's. Distinguishable from F. kohdti by deeper ap^^ressed suture, stronger, revolving ridges, narrower form, and lack of wavy sutural band on posterior edge of whorl. F. robustus is probably a precursor of F. kohelti. This species has been identified as F. amhustus by many West Coast conchologists, including Cooper and perhaps Carpenter. Speci- mens identified by Dr. Dall. Found only in the upper San Pedro series; rather common at Old San Pedro. Found also in the Pleistocene at the bath-house, Santa Barbara. Living. — Santa Barbara to San Diego (California State Museum). Pleistocene. — Santa Barbara (Cooper; Arnold): San Pedro (Trask; Arnold). 210. Fusus rugosus Trask. Plate IV, Fig. 7. Fusus rugos/is Trask, Proc. Cal. Acad. Sci., Vol. I, 1855, p 41. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 241. Shell of medium size, elongate, fusiform, thin; whorls eight, convex, crossed by eight to eleven rounded ridges, which rise to greatest prominence on upper side of whorl; body-whorl ventri- cose and sometimes lacking transverse ridges on forward part; surface ornamented with several prominent raised lines, with fine lines sometimes intercalated; suture deeply appressed, wavy; aperture elliptical; outer lip thin, with interior spiral ridges extending nearly to rim; inner lip smooth; columella long, slightly twisted, spirally ridged; canal long, narrow, slightly curved. Dimensions. — Long. 50 mm.; lat. 19 mm.; body-whorl 35 mm.; aperture, including canal, 28 mm.; canal 13 mm.; defl. 44 degrees. The specimen described and figured is a small one. Some of the specimens are over 65 mm. in length. Distinguishable from F. robustus by larger size, thinner shell, longer canal, more ventricose body-whorl, and greater development of transverse ridges on ujiper portion of whorl. Perhaps F. rugosus is the precursoi- of F. robustus. If so, then ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDEO. 227 rohustus is a degenerate form in so far as size and beauty go, for rugosus is truly a magnificent shell, while the former is small and much less attractive. This species has been identified as F. amhiistus, and is so labeled in the State Museum collection at Berkeley. F. nmbusfus of Gould is a slenderer, longer pillared form from Central America. Found only in the lower San Pedro series of Deadman Island. The shells in this horizon are beautifully preserved, this form especially being nearly always found in a perfect condition, and having a shell that in most cases is translucent. Rather rare. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living.—Santa Barbara to San Diego (California State Museum). Pleistocene.— Santa Barbara (Cooper): San Pedro (Arnold; Trask). Genus Pisania Bivona. Shell oblong; spire prominent; whorls smooth or spirally striated; canal very short; outer lip thickened and crenated. Pisania pusio Linn, is a characteristic species. 211. Pisania fortis Carpenter. Pisania foriis Cpr., Ann. & Mag. Nat. Hist., 3rd Sen, Vol. XVII, 1866, p. 277. Cooper, 7th Ann. Rept. Cal. St. Min.. 18S8, p. 260. Shell fusiform, short; spire elevated; apex subacute; whorls five or six, convex on upper whorls to angular on body-whorls; eight wave-like ribs, most prominent on the angle of the whorl; prominent sutural riblet on posterior margin of whorl; surface ornamented with three to five promi- nent, squarish, rough, revolving ridges, between which are finer raised lines; suture wavy, appressed, distinct; aperture pyriform; outer lip denticulated; umbilicus subperforate. Dimensio7is. — Long. 49 mm.; lat. 29 mm.; body-whorl 38 mm.; aperture 25 mm.; defl. 58 degrees. This species resembles some specimens of Purpura crispata, but is a lighter shell, and the sculpture is entirely different. Originally described from a specimen from the Pleistocene of Santa Barbara. It has never been found living. Rare in the upper San Pedro series of San Pedro and Deadman Island; two specimens found. Found in the Pleistocene at Pacific Beach, San Diego. Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold). Family LVIII. BUCCINID^. Genus Chrysodomus Sivainson. Shell fusiform, ventricose; spire elevated; whorls rounded; covered with a horny epidermis; apex papillary; aperture oval; canal short; inner lip simple, smooth. Chrysodomus antiqua Linn, is a characteristic species. 228 CALIFORNIA ACADEMY OF SCIENCES. 212. Chrysodomus rectirostris Carpenter. Plate VII, Fig. 7. Chrysodomus rectirostris Qvv.., Brit. Assn. Rept., 1863, p. 664; Proc. Phil. Acad. Nat. Sci., 1865, p. 64. Tryon, Man. Conch., Vol. II, p. 131, PL LIII, fig. 348, 1881. Shell small, turreted, slender; apex acute; whorls nine or ten, slightly conve.x, with about fourteen rounded, transverse ridges reaching from suture to suture; ridges follow direction of lines of growth, which are convex anteriorly; spiral sculpture consists of numerous fine furrows; suture impressed, distinct; body-whorl slightly angulated at base; aperture elliptical; outer lip thin, bulging above canal; inner lip smooth, incrusted; columella long, straight, narrow, smooth on inner part; canal long, straight, narrow. Dimensio7is. — Long. 28 mm.; lat. 7 mm.; body-whorl 14.5 mm.; aperture, including canal, 1 1.5 mm.; canal 5 mm.; defl. 22 degrees. This species looks something like a Pleurotoma, but may be distinguished by the straight canal and almost flat whorls. Carpenter's description in the British Association Report for 1863 is misleading. In describing this species he says the shell is "small, white, smooth, with straight canal." Why he uses "smooth" in describing such a decidedly sculptured form is not easy to understand. Sevei'al specimens of this species were identified from Carpenter's type by Dr. Dall. Rare in the Pliocene and lower San Pedro series at Deadman Island, and in the upper San Pedro series at Crawfish George's. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Puget Sound (Carpenter). Pleistocene. — San Pedro (Arnold). 213. Chrysodomus tabulatus Baird. Plate VII, Fig. 0. Chrysodomus tabulatus Baird, Proc. Zool. Soc, 1863, p. 66. Cpr., Brit. Assn. Rept., 1863, p. 663; Nat. in British Columbia, Vol. II, p. 356. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 235. Neptwiea tabulaia "Qmrd, GAYiv,, Pal. Cal., Vol. II, p. 71, 1869. Tryon, Man. Conch. , Vol. II, p. 121, PL XLIX, fig. 286, 1881. Shell large, fusiform; spire elevated; apex subacute; whorls eight, sharply angulated and keeled above, forming a rimmed, spiral table; surface ornamented with revolving ridges of alternating size; suture very deeply impressed; aperture pyriform; outer lip thin, smooth; inner lip incrusted; canal long, narrow, curved backwards; columella twisted, spirally ridged. Dimensions. — Long. 80 mm.; lat. 34 mm.; body-whorl 55 mm.; aperture, including canal, 42 mm.; canal 19 mm.; defl. 44 degrees. Rather common in Pliocene; rare in lower San Pedro series of Deadman Island and San Pedro. Found also in the Pleintocene at the bluflf west of the bath- bouse, Santa Barbara, and at the old irrigating ditch north of Ventura. The AKNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDKO. 229 specimen figured was from the Pliocene, Deadman Island, and is now in the collec- tion of Delos Arnold. Living. — Straits of Fuca to Catalina Island (Cooper). Pleistocene.— &iin Pedro; Santa Barbara; Ventura (Arnold). Pliocene. — Eagle Prairie; Twelve Mile House; San Fernando; Santa Barbara (Cooper); San Pedro (Cooper; Arnold). 214. Chrysodomus, sp. indet. Two poorly preserved, undeterminable species; both fusiform, one with rounded whoi'ls, the other slightly tabulated on upper part; fine spiral sculpture on both. These specimens have the shape of C. dims. They correspond quite closely to the descriptions of some of tlie living species which now inhabit boreal waters. Found in the Pliocene of Deadman Island. Pliocene. — San Pedro (Arnold). Genus Siphonalia A. Adams. Shell ovately fusiform, sometimes variegated in coloring; rather thin; epidermis very thin, fugacious; last whorl ventricose, shouldered, usually nodosely plicate and spirally ribbed; aperture oval; outer lip thin; columella smooth; canal rather short, twisted. Siphonalia nodosa Mart, is a characteristic species. 215. Siphonalia kellettii Forbes. Plate IV, Fig. 5. Siphonalia kellettii ¥o^hKS, Proc. Zool. Sec, 1850, p. 274, Pi. X, fig. 10. Cpr., Brit. Assn. Rept., 1863, p. 663. Tryon, Man. Conch., Vol. Ill, p. 134, PL LIV, fig. 352. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part. I, 1890, p. 122. Keep, West Coast Shells, p. 22, 1S92. Shell large, fusiform; spire elevated; apex subacute; whorls seven or eight, angulated anterior to middle with eight to ten prominent nodes on angle; concave near posterior margin, where it is appressed against the antecedent whorl; numerous fine, deep grooves furnish the spiral ornamentation; suture appressed, wavy; aperture ovate; outer lip not thickened; inner lip incrusted; columella twisted; umbilicus subperforate; canal long, narrow, curved back. Dimensions. — Long. 114 mm.; lat. 59 mm.; body-whorl 80 mm.; aperture 37 mm.; canal 22 mm.; defl. 44 degrees. Often brought up alive in the nets of fishermen at San Pedro, but rarely found fossil. Found in the upper San Pedro series at San Pedro, Los Cerritos, and Crawfish George's. Found also in the Pleistocene at Pacific Beach, San Diego. The speci- men figured was obtained in the upper San Pedro series at San Pedro, and is now in the private collection of Delos Arnold. Living. — Santa Barbara to San Diego; Japan (Cooper). 230 • CALIFORNIA ACADEMY OF SCIENCES. Pleistocene. — San Pedro to Sau Diego (Cooper) : Sau Pedro; Sail Diego (Arnold). Genus Macron //. <£■ A. Adams. Shell ovate, solid, with a thick epidermis; spire elevated; columella wrinkled, with a callosity at the upper part; outer lip thin, with a small tooth anteriorly. Type, Macron kelkttii A. Ads. 216. Macron kellettii A. Adams. Pscudoliva kellettii A. Ad., Proc. Zool. Soc, 1853, p. 185. Macron kellettii h. Ad., Cpr., Brit. Assn. Rept., 1863, p. 664. Tryon, Man. Conch., Vol. Ill, p. 214, PI. LXXXII, fig. 477, 1881. Keep, West Coast Shells, p. 21, 1892. Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 27. Shell ovate, solid, subperforate; spire prominent; whorls rounded; suture canal-like; last whorl spirally sulcated; aperture oval; columella callous posteriorly, anterior portion produced and flexed; posterior part of lip bent, anterior part dentate. Canal a mere notch. Average length about 25 mm. One specimen in upper San Pedro series of San Pedro. Living. — Lower California (Keep): Catalina Island to Lower California (Cooper). Pleistocene. — San Pedro (Arnold) : San Joaquin Bay, Orange County (Bowers). Pliocene. — Ventura County (Bowers). 217. Macron lividus A. Adams. Macron lividus A. Ad., Cpr., Brit. Assn. Rept.. 1863, p. 664. Keep, West Coast Shells, p. 20, fig. 2, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 216. Shell small, ovate, solid; spire elevated; apex subacute; whorls five, evenly convex, smooth; suture distinct; aperture ovate; outer lip sharp and curved; inner lip short and bent; columella with a strong fold near the top of the aperture. Dimensions. — Long. 19 mm.; lat. 10 mm.; body-whorl 14 mm.; aperture 10 mm. This species is characterized by its smooth surface and small size. One specimen found in the upper San Pedro series at the lumber yard, San Pedro. Living. — San Pedro (Williamson) : San Diego to Lower California (Carpenter). Pleistocene. — San Pedro (Arnold). Family LIX. NASSID^E. Genus Nassa Lamarck. Shell ovate, ventricose; body- whorl variously sculptured; aperture ovate, with a short, reflected, truncated, anterior canal; inner lip smooth; often widely spread over with enamel, with a posterior callosity or a blunt dentiform; outer lip dentated, internally crenulated. Nassa mutahilis Linn, is a characteristic species. ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDUO. 231 2i8. Nassa californiana Conrad. Plate IV, Fig. 3. Schizopyga calif orjiiana Con., Proc. Phil. Acad. Nat. Sci., 1856, p. 315; Pac. R. R. Rept., Vol. VI p. 69, PL II, fig. I, 1857. Schizopyga californica CoN., Tryon, Man. Conch., Vol. IV, p. 55, PI. Ill, fig. 32, 1882. Nassa californiana Con., Dall, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 177. Cooper, Bull. No. 9, Cal. St. Min. Bureau, Part 3, 1894, p. 29. Nassa fossata van, Gabb, Pal. Cal., Vol. II, pp. 47, 74, 1869. Shell large, conical; whorls seven, convex, ornamented with about thirteen prominent, rounded, posteriorly sloping, transverse ribs and four or five' slightly less prominent sharp, revolving ridges; the transverse ridges tend to become less prominent on the anterior part of the body-whorl; suture deeply impressed, distinct; aperture subovate; outer lip thin and denticulated by ends of internal revolving ridges; inner lip slightly incrusted; columella short, twisted, spirally and longitudi- nally ornamented, and deeply grooved next to body-whorl; anterior sinus very short, broad, recurved. Dimensions.- — Long. 37 mm.; lat. 20.5 mm.; body-whorl 24 mm.; aperture 16.5 mm.; defl 48 degrees. The most beautiful and one of the hirgest of the Pleistocene Nassau. Easily- distinguishable by the ornamentation and size. Rare in the upper San Pedro series, except at one place in the bluf! just north of the town of San Pedro, where quite a few very fine specimens have been found; also found in the Pliocene and lower San Pedro series at Deadman Island; and in the upper San Pedro series at Los Cerritos, Deadman Island, and Long Beach. Found also in the Pleistocene at Barlow's ranch, Ventura; and at Pacific Beach, San Diego. The specimen figured is from the upper San Pedro series of San Pedro; and is now in the private collection of Delos Arnold. Living. — Drake's Bay to Cedros Island, Lower California (Cooper). Pleistocene. — San Pedro; Ventura; San Diego (Arnold). Pliocene. — San Pedro (Arnold). Miocene. — Santa Clara County (Cooper). 219. Nassa cerritensis, sp. nov. Pl.\te IV, Fig. 1. Shell small, conical; spire elevated; apex subacute; whorls eight, slightly convex, crossed by seven to ten prominent, rounded ridges which are less prominent near the suture; spiral sculp- ture consists of nine to eleven sharp, raised lines; three upper whorls have a cancellate appearance; suture appressed, wavy; aperture ovate; outer lip thickened by denticulated ridge on inner side; inner lip smooth, incrusted, the incrustation completely covering the spiral sculpture internally; columella twisted, spirally sculptured, with deep groove next to body-whorl; canal short, broad, recurved. Dimensions. — Long. 30 mm.; lat. 14.5 mm.; body-whorl 18 mm.; aperture 11 mm.; defl. 30 degrees. This species varies ranch, especially in deflection and in tlie number of trans- verse ridges. The deflection of the upper whorls is sometimes as high as 60 degrees, 232 CALIFOllNIA ACADEMY OF SCIENCES. while that of the lower whorls would be about one-half of that. Home of the adult shells also show a deflection of 50 degrees. The robust shells as a rule show more transverse ridges than the slenderer forms. Distinguishable from var. cooperi by less angulated whorls and ridges, less impressed suture, greater deflection of upper whorls, and larger size. The robust form somewhat resembles N. californiana, but is distinguishable from that species by its appressed, rather than impressed suture, less prominence of spiral lines, and smaller size. Dr. Dall pronounces this species a precursor of JSF. coojjeii. Rather common at Los Cerritos, where the type was found. One or two specimens found in the upper San Pedro series at San Pedro, Long Beach, and Crawfish George's. Found also in the Pleistocene at Spanish Bight, San Diego. The specimen figured is the type, which came from the upper San Pedro series at Los Cerritos, and is now in the United States National Museum. Pleistocene. — San Pedro; San Diego (Arnold). 220. Nassa fossata Gould. Buccinum fossaiuvi Gld. , Proc. Bost. Soc. Nat. Hist., 1850, p. 152. Otia, Conch., p. 67, 1862. Nassa fossata Gld., H. & A. Adams, Gen. Rec. Mollusca. Cpr., Brit. Assn. Rept., 1863, p. 662. Gabb, Pal. Cal., Vol. II, p. 74, 1S69. Tryon, Man. Conch., Vol. IV, p. 55, PI. XVII, figs. 316, 318, 1882. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 253. Keep, West Coast Shells, p. 36, fig. 16, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 212. Shell small, conical; spire elevated; apex subacute; whorls seven, convex; body-whorl ventricose; ornamentation of fourth and fifth whorl consists of five or si.x strong, nodose, spiral ridges which increase in number by intercalation on the lower whorls; the prominence of the nodes varies inversely with the number of ridges, the ridges on the body-whorl being nearly smooth and alternating large and small; the ridges near the angle of the whorl reach the greatest prominence; suture deeply impressed, distinct; aperture ovate; outer lip thickened and denticulated by ends of revolving internal ridges; inner lip incrusted, the incrustation spreading over part of body-whorl and columella; columella short, curved, spirally striated, and grooved deeply next to body-whorl; anterior sinus short, broad, recurved. Dimejisions. — Long. 29 mm.; lat. 17 mm.; body-whorl 21 mm.; aperture, including canal, 14.5 mm.; defl. 50 degrees. The adolescent shell of this species resembles iV^. ferpinguis,, but may be distinguished by the greater convexity of the body-whorl, greater deflection, and general more solid appearance. The adult shells are characterized by their general solid appearance, great deflection, and the great difference in sculpture between the upper and lower whorls. Found in the Pliocene at Deadman Island; in the lower San Pedro series at Deadman Island and San Pedro, and in the upper San Pedro series at all of the localities in the vicinity of San Pedro. Found also in Pleistocene at Spanish Bight and Pacific Beach, San Diego; and at old irrigating ditcli and Barlow's ranch. ARNOLB — THE PALEONTOLOGY AND STEATIGEAPHY OF SAN PEDRO. 233 Ventura. The specimens of this species found at Crawfish George's are character- ized by their large size and elevated spire, with deeply impressed suture. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura; San Diego (Arnold). Pliocene. — Danger Creek; Santa Rosa; Soquel, Santa Cruz County; San Diego well (Cooper): San Pedro (Arnold). Miocene. — Martinez; Walnut Creek; Griswold's, San Benito County; Foxin's, Santa Barbara County (Cooper). 221. Nassa insculpta Carpenter. Nassa insculpta Cpr., Brit. Assn. Rept., 1863, p. 662; Proc. Cal. Acad. Sci., Vol. Ill, 1866, p. 223. Tryon, Man. Conch., Vol. IV, p. 38, PI. XII, fig. 154, 1882; (not of Cooper, ytli Ann. Rept. Cal. St. Min., 1S88, p. 253). Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 2X2, PI. XXIII, fig. 6. Shell small, conical; spire elevated; apex subacute; whorls seven, nearly flat, but obliquely truncated near margin; sculpture consists of numerous fine, spiral furrows, which are most promi- nent on lower portion of body-whorl; four upper whorls have prominent transverse ridges; aperture subquadrate; outer lip thickened by a slightly denticulated ridge; inner lip incrusted slightly, but spiral ornamentation shows through the incrustation; columella short and separated from body-whorl by deep, narrow groove; canal short, broad, curved. Dimensions. — Long. 20 mm.; lat. 11 mm.; body-whorl 12.8 mm.; aperture, including canal, 9 mm.; defl. 38 degrees. Distinguishable by lack of any but spiral ornamentation on lower whorls. A specimen in the State Museum collection at Berkeley labeled N . insculpta is not the species, but is close to JSf. versicolor var. hooveri. This is probably the specimen upon which Cooper bases his report of the occurrence of A^. insculpta at Santa Barbara. Bare in upj)er San Pedro series of San Pedro; one specimen. Living. — Catalina Island (Cooper; Raymond). Pleistocene. — San Pedro (Williamson; Arnold). 222. Nassa mendica Gould. Nassa mendica Gld., Proc. Bost. Soc. Nat. Hist., 1850, p. 155. Wilkes' E.xpl. Exped., Vol. XII, p. 263, PI. XIX, fig. 331, 1852. Otia, Conch., p. 70, 1862. Cpr., Brit. Assn. Rept., 1863, p. 662; ^=M. woodwardi Fbs.; =A^. gibbsii Cooper {Jide Tryon, Man. Conch., Vol. IV, p. 56, PI. XVII, figs. 320-323, 1882). Gabb, Pal. Cal., Vol. II, p. 74, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 253. Keep, West Coast Shells, p. 37, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213. Shell small, conical; spire elevated; apex acute; whorls seven, convex; ornamented with a varying number of transverse ridges and a few less prominent spiral ridges; suture deeply impressed, distinct; aperture subquadrate; outer lip thin, smooth on edge, but denticulated remote from margin; inner lip incrusted; columella curved, spirally striated, and separated from body-whorl by deep groove; canal short, recurved. Dimensions. — Long. 18.5 mm.; lat. 8 mm.; body- whorl 11 mm.; aperture, including canal, 7.5 mm.; defl. 38 degrees. ( 30 ) March 20, 1903. 234 CALIFORNIA ACADEMY OF SCIENCES. A species varying principally in the number and prominence of transverse ridges. Distinguishable from N. perpinguis by acuteness of spire. Found in all of the fossiliferous formations at all of the localities in the vicinity of San Pedro. N. mendica is much rarer than the variety cooperi. Found in the Pleistocene at the bath-house, Santa Barbara; at Barlow's ranch, and the old irri- gating ditch, Ventura; and at Spanish Bight and Pacific Beach, San Diego. Living. — Sitka to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa Barbara; Ventura; San Diego (Arnold). Pliocene. — Kirker's Pass; Twelve Mile House, San Mateo County; San Diego well (Cooper): San Pedro (Arnold). 223. Nassa mendica Gould, var. cooperi Forbes. Nassa cooperi Fbs. , Froc. Zool. Soc, 1850, p. 273, PI. XI, fig. 4. Cpr., Brit. Assn. Rept, 1863, p. 662. Gabb, Pal. Cal., Vol. II, p. 74, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 253. Keep, West Coast Shells, p. 37, fig. 18, 1892. JVassa metidica var. cooperi Fbs., Tryon, Man. Conch., Vol. IV, p. 56, PI. XVII, figs. 322,323, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213. Shell like A/', mendica, except that the transverse ridges are more prominent and less numerous. Mutations occur between the extreme N. mendica with latticed ornamentation consisting of equally prominent spiral and transverse ridges, and the extreme N. cooperi with only six large, transverse ribs. More common than the typical N. mendica. Found in the lower and upper San Pedro series and Pliocene of the San Pedro region. Found in the Plei.stocene at Pacific Beach, San Diego. Living. — Sitka to San Diego (Cooper): Catalina Island (Stearns). Pleistocene — Santa Barbara to San Diego (Cooper): San Pedro; San Diego (Stearns; Arnold). Pliocene. — Kirker's Pass; Twelve-mile House, San Mateo County; San Diego well (Cooper): San Pedro (Arnold). 224. Nassa perpinguis Hinds. Nassa perpinguis Hds., Voyage Sulphur, p. 36, PL IX, figs. 12, 13, 1844. Cpr., Brit. Assn. Rept., 1863, p. 662; Gabb, Pal. Cal., Vol. II, pp. 47, 75, 1869. Tryon, Man. Conch., Vol. IV, p. 56, PI. XVII, fig. 319, 1882. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 253. Keep, West Coast Shells, p. 38, fig. 19, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213. Nassa inierstriaia, Con., Pac. R. R. Rept, Vol. V, p. 327, PI. VI, fig. 49, 1856. Shell small, conical; spire elevated; apex subacute; whorls seven, convex, abruptly truncated at posterior margin, forming a spiral table; ornamentation consists of sharp, spiral ridges with slightly wider interspaces, and posteriorly sloping transverse ridges, the whole giving a decidedl)' cancellate appearance to the surface; suture deeply impressed, distinct; aperture subovate; inner ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 235 portion of aperture ridged by spiral sculpture; outer lip thin; inner lip thinly incrusted; columella twisted and spirally ornamented; groove on upper part of columella prominent; canal short, curved. Dijnensions. — Long. 23 mm.; lat. 12.3 mm.; body-whorl 15 mm.; aperture, including canal, II mm.; defl. 40 degrees. The transverse ornamentation is the most prominent in the upper whorls, while in the later ones the spiral ridges are the most important. On the body-whorl the tranverse ridges sometimes become nearly obsolete, being represented only by lines of growth. Common in the upper and rare in the lower San Pedro series at San Pedro and vicinity. Also found in the Pliocene at Deadman Island and Timm's Point. Found in the Pleistocene at Spanish Bight and Pacific Beach, San Diego; and at the old irrigating ditch and Barlow's ranch, Ventura. Living. — San Francisco to San Diego; Lower California (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura; San Diego (Arnold). Pliocene. — San Diego well (Dall): San Pedro (Arnold). Miocene. — Santa Monica and Aliso Creek, Los Angeles County (Cooper). 225. Nassa tegula Reeve. Nassa tegula Rye., Icon. Conch., Nassa, No. 98, PI. XV, 1853. Cpr., Brit. Assn. Rept., 1863, p. 662. Gabb, Pal. Cal., Vol. II, p. 74, 1869. Tryon, Man. Conch., Vol. IV, p. 39, PI. XIII, figs. 166, 167, 1882. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 253. Keep, West Coast Shells, p. 37, fig. 17, 1892. Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213. Shell small, conical; spire elevated; apex subacute; whorls five, slightly angulated at middle, with nine or ten prominent transverse ridges most prominent on angular part of whorl; these ridges are sometimes divided by spiral grooves into two or more nodes; suture impressed, distinct; aper- ture subquadrate; outer lip thickened by a row of elongated denticles; inner lip smooth and incrusted, the incrustation spreading over the columella and the front of the shell like an apron; a rather shallow groove separates the lower portion of columella from body-whorl; canal very short. • Dimensions. — Long. 11 mm.; lat. 7 mm.; body-whorl 7.9 mm.; aperture, including canal, 5 mm.; defl. 58 degrees. The most robust of the Naa&as, found in this locality. Distinguishable by the prominence of the incrustation on the inner lip. Dr. Dall says that this species is close to jV. vihex of the Atlantic coast. Rare in the upper San Pedro series at San Pedro, Los Cerritos, Long Beach, Deadman Island, and Crawfish George's; also occasionally found in the lower San Pedro series at Deadman Island and San Pedro. Found also in the Pleistocene at Twenty-sixth Street and Spanish Bight, San Diego. Living. — Santa Barbara to San Diego; Lower California (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego (Arnold), 236 CALIFOKNIA ACADEMY OF SCIENCES. 226. Nassa versicolor C. B. Adams, var. hooveri, var. iiov. Plate IV, Fig. 6. Nassa versicolor C. B. Ad., Panama Cat., p. 66, 1852. Tryon, Man. Conch., Vol. IV, p. 50, PI. XV, figs. 270-272, 275, 1882. Shell small, conical; spire not highly elevated; apex subacute; whorls six, slightly convex, crossed by fifteen prominent rounded ribs which bend slightly forward on the upper whorls, and are abrupdy truncated at the sutures; on the body-whorl these ribs are concave anteriorly and become obsolete on the lower portion of the whorl; ribs on the upper whorls are of uniform size for their full length; suture deeply impressed, distinct; spiral ornamentation consists of eleven to thirteen grooves, which extend to base on body-whorl; columella extended, plication on inner side, and deep, narrow groove around it at base of body-whorl; outer lip thickened by a prominent, smooth ridge on the inner side; inner lip incrusted, the spiral sculpture, however, showing through the incrustation; canal short, broad, with effuse lips. Dimensiots. — Long. 14.5 mm.; lat. 9 mm.; body-whorl 10 mm.; aperture, including canal, 7 mm. ; defl. 54 degrees. A unique form for this locality; somewhat resembles N. tegula in shape, but easily distinguishable from that species by the sculpture. Pronounced a variety of ]Sr. versicolor Adams, by Dr. Dall. N. versicolor is found in the southern fauna, its habitat being Panama to Mazatlan according to Tryon. Hare in upper San Pedro series of San Pedro; two specimens found, one a junior. The specimen figured is the type, which was obtained from the upper San Pedro series of San Pedro, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Family LX. COLUMBELLIDiE. Genus Colvimbella Lamarck. Shell strombiform or obovate, smooth or longitudinally or tranversely ribbed; internal lip excavated in the middle, crenulated or denticulated; outer lip inflected and internally thickened and crenulated in the middle. Columbella mercatoria Lam. is a characteristic sjiecies. 227. Columbella solidula Reeve, var. praecursor, var. nov. Plate X, Fig. 4. Columbella solidula RvE., Conch. Icon., Vol. XI, PI. XXIV, fig. 149, 1859. Tryon, Man. Conch., Vol. V, p. 147, PI. LII, figs. 92 and 93, 1883. Shell small, broadly fusiform; spire elevated; apex rounded; whorls seven, only slightly convex, slightly shouldered above, smooth; body-whorl two-thirds length of shell, with row of nodes on shoulder, each node being the termination of a faint transverse ridge which becomes obsolete on lower portion of whorl; columella with spiral sulcations on exterior; aperture rhomboidal, narrow; outer lip thickened internally by row of prominent teeth; inner lip smooth; canal short, recurved. Dimensions. — Long. 14.5 mm.; lat. 6.5 mm.; body-whorl 10 mm.; aperture, including canal, 7.5 mm.; canal i mm.; defl. 42 degrees. ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDKO. 237 This unique species is distinguishable by its smooth upper whorls, and sculp- tured body-whorl. Pronounced a variety of C. solidula Rve. by Dr. Dall. The shell of which this form is a variety is found living on the coast of Ecua- dor, South America. The type is the only specimen that has been found in the upper San Pedro series at San Pedro; it is figured, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Subgenus Anachis //. it A. Adams. Shell oval-fusiform, longitudinally ribbed; spire elevated; aperture narrow; columella straight; outer lip nearly straight, crenulated within. AnacMs rugosa Sowerby is a characteristic species. 228. Columbella (Anachis) minima, sp. uov. Plate IX, Fig. 8. Shell small, resembles a young Amphissa corrugata but much slenderer; surface sculptured by numerous transverse ridges and fine spiral sulcations; whorls six, shouldered above as in Amphissa versicolor; aperture subquadrate; outer lip nearly straight; pillar straight, spirally striated. Di7nensions. — Long. 6 mm.; lat. 2.4 mm.; body-whorl 3.5 mm.; aperture 2.2 mm.; defl. 28 degrees. Distinguishable from Amphissa corrugata by slenderer form, more shouldered whorls and less wavy transverse ridges. Pronounced a new species of Anachis by Dr. Dall. Type from upjier San Pedro series of San Pedro; rare. The specimen figured is the type, which is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Subgenus .ffisopus Gould. Shell fusiform, gibbous, broadly truncate in front; aperture lunate, with a posterior callous on the body; columella smooth, vitreous; suture abnormally arcuate near the aperture. Type, ^sopus japonicus Gould. 229. Columbella (.Ssopus) chrysalloidea Carpenter. Plate V, Fig. 6. Amycla chrysalloidea Cpr., Brit. Assn, Rept., 1863, p. 612; Proc. Cal. Acad. Sci., Vol. Ill, 1S64, p. 223. Columbella chrysalloidea Cpr., Tryon, Man. Conch., Vol. V, p. 135, PL L, fig. 42, 1883. Astyris chrysalloidea Cpr., Keep, West Coast Shells, p. 36, 1S92. Columbella {y£sopus) chrysalloidea Cpr., Williamson, Proc. U- S. Nat. Mus., Vol. XV, 1892, p. 213. Shell small, with general elongate-ellipdcal oudine, or chrysalis-shaped; spire elevated, sub- acute; whorls six, very slightly convex; surface marked by delicate spiral ridges and furrows; 238 CALIFOKNIA ACADEMY OF SCIENCES. aperture ovate; canal short; outer lip thickened by several longitudinally elongate denticles on inner side; inner lip curved, smooth; spiral ornamentation prominent on lower portion of columella. Dimensions. — Long. 8.2 mm.; lat. 3 mm.; body-whorl 5.5 mm.; aperture 3.4 mm.; defl. 44 degrees. Rare in the lower San Pedro series at Deadman Island and San Pedro; not uncommon in the upper San Pedro series at San Pedro. Found also in the Pleisto- cene at Twenty-sixth street, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — San Pedro to San Diego (Cooper). Pleistocene. — San Pedro; San Diego (Arnold). 230. Columbella (.ffisopus) oldroydi, sp. nov. Plate VI, Fig. 7. Shell small, slender, fusiform; spire elevated; apex rounded; whorls seven, convex; first three whorls smooth, remainder, with exception of body-whorl, ornamented with about eighteen transverse ridges and two or three rather indistinct spiral grooves, the whole giving a cancellate appearance to the surface; on the body-whorl the transverse and spiral sculpture are of about equal prominence, the transverse sculpture being more subdued than on the whorls above it; suture quite deeply impressed; aperture narrow, elliptical; pillar truncated anteriorly; outer lip smooth, thin; inner lip smooth. Dimensions. — Long. 9 mm.; lat. 2.6 mm.; body-whorl 5 mm.; aperture 3 mm.; defl. 24 degrees. Distinguishable from A. chrysalloidea by slenderer form, prominently sculp- tured surface, deeper suture, and smooth inner lip. Pronounced a new species by Dr. Dall. Lower San Pedro series at Deadman Island; rare. The specimen figured is the type, and is now in the collection of Mrs. Oldroyd. Pleistocene. — San Pedro (Arnold). Subgenus Astyris //. ct A. AJams. Shell oval-fusiform, smooth or transversely striated; aperture oval; inner lip smooth, not callous; outer lip sinuous posteriorly, crenulated within. Astyris clausilimforme Kiener is a characteristic species. 231. Columbella (Astyris) californiana Gaskoin. Pl.\te X, Fk;. 9. Columbella {Astyris) californiatia Gask., Proc. Zool. Soc, 1851, p. 12. Columbella californiana Gask., Cpr., Brit. Assn. Rept., 1856, p. 341. This species resembles A. cjausapata quite closely, but differs from it in the following respects: it is slightly broader, has more swelling whorls, more prominent AENOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDKO. 239 spiral lines on the lower part of the body-whorl, does not have the overla^^ping apjiearance of the wliorls at the suture as much as in A. gausapata, has a less heavy shell, and has a less glossy surface. SiJecimen identified by Dr. Dall. Rare in the lower San Pedro series at Deadman Island, also found in the lower San Pedro series at San Pedro. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Santa Barbara to San Diego (Carpenter). Pleistocene. — San Pedro (Oldroyd; Arnold). 232. Columbella (Astyris) gausapata Gould. Plate X, Fig. 8. Columbella gausapata Gld. , Proc. Bost. Soc. Nat. Hist., 1S50, p. 170; Wilkes' Expl. Exped., Vol. XII, p. 267, PI. XIX, fig. 337, 1852. Nassa pedroana Con., Pac. R. R. Rept.. Vol. V, p. 327, PI. VI, fig. 48, 1S56. Amycla gausapata Gld., Cpr., Brit. Assn. Rept., 1863, p. 662. Gabb, Pal. Gal., Vol. II, p. 76, 1S69. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 229. Astyris gausapata Gld., Keep, West Coast Shells, p. 35, fig. 15, 1892. Colu7nbella (^Astyris) gausapata Gld., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1S92, p. 213. Shell small, rather heavy; spire elevated; apex acute; whorls seven, slightly convex; body- whorl ventricose, slightly angulated; whorls smooth except for delicate incremental lines; suture depressed, distinct; columella recurved and striated on outside with faint spiral ridges and grooves; aperture elongate-ovate; canal prominent, slightly curved; outer lip thickened with a row of spirally elongate denticles; inner lip smooth. Dime7isio7ts. —1.0-ng. 11 mm.; lat. 5 mm.; body-whorl 7 mm.; aperture (not including canal) 3 mm-X i-9 mm.; defl. 35 degrees. Distinguishable from C. californiana by much longer canal, thicker shell, and more prominent denticulation of outer lip; distinguishable from C. tuberosa by broader spire and less angulated body-whorl; distinguishable from var. carinata by lack of keel, and slenderer sjiire. Specimens identified by Dr. Dall. Found in all of the formations at all of the localities in the vicinity of San Pedro. Found also in the Pleistocene at the bath-house, Santa Barbara; at Barlow's ranch and the old irrigating ditch, Ventura; and at Twenty-sixth Street and Pacific Beach, San Diego. Much rarer than var. carinata. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Alaska to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura; Santa Barbara; San Diego (Arnold). Pliocene. — Kirker's Pass (CoojJer). 240 CALIFORNIA ACADEMY OF SCIENCES. 233. Columbella (Astyris) gausapata Guu/d, var. carinata Hinds. Plate X, Fig. 10. Columbella carinata Hds., Voyage Sulphur, p. 39, PI. X, figs. 15, 16, 1844. Cpr., Brit. Assn. Rept., 1863, p. 662. Tryon, Man. Conch., Vol. V, p. 116, PI. XLVII, figs. 35-39, 1883. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213. Amycla carhiala Hds., Gabb, Pal. Cal., Vol. II, p. 76, 1869. Aslyris gausapata var. carinata Hds., Keep, West Coast Shells, p. 35, 1892. Shell like A. gausapata, except that it has a distinct keel on the upper part of the whorl. A large series of shells shows mutations between the typical gausapata and this variety. An extreme keeled form gives the following dimensions: Long. 8 mm.; lat. 4.1 mm.; body-whorl 5 mm.; aperture 3.5 mm. Common in all of the formations at all of the localities in the vicinity of San Pedro; much commoner than C. gausapata. Found also in the Pleistocene at the old irrigating ditch north of Ventura; at bath-house, Santa Barbara; and at Spanish Bight, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Santa Barbara to San Diego (Cooper). Pleistocene. — Santa Barbara to San Pedro (Cooper): San Pedro; Ventura; Santa Barbara; San Diego (Arnold). 234. Columbella (Astyris) tuberosa Carpenter. Plate X, Fig. 7. Amycla tuberosa Cpr., Brit. Assn. Rept., 1863, p. 662; Ann. & Mag. Nat. Hist., 3rd Sen, Vol. XV, 1865, p. 398. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 229. Astyris tuberosa Cpr., Stearns, Proc. Cal. Acad. Sci., Vol. V, 1873, p. 81. Keep, West Coast Shells, p. 36, 1892. Columbella tuberosa Cpr., Tryon, Man. Conch., Vol. V, p. 135, PI. L, figs. 40 and 41, 1883. Columbella {Astyris) tuberosa Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213^ PI. XX, fig. 6. Shell small, slender; spire elevated; acute apex; whorls seven, only slightly convex; body- whorl angulated, lower portion decidedly concave and ornamented with narrow grooves and ridges; surface of upper whorls smooth except for delicate incremental lines; suture distinct; aperture ovate, and less than one-half the length of shell; anterior end of columella slender; outer lip thickened by row of tubercles on inner side; inner lip smooth; canal short, straight. Dimensions. — Long. 6.5 mm.; lat. 2.8 mm.; body-whorl 4 mm.; aperture 2.9 mm.; defl. 22 degrees. Distinguishable from other members of genus by slender spire and angulated body-whorl. Rare in the lower San Pedro series at Deadman Island and San Pedro; and in the upper San Pedro series at Crawfish George's, Los Cerritos, San Pedro, and Deadman Island. Found also in the Pleistocene at Spanish Bight, San Diego; ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDKO. 241 and at bath-house, Santa Barbara. The specimen figured is from the upper Ban Pedro series at Sau Pedro, and is now in the collection of Delos Arnold. Living. — Neah Bay to San Diego (Cooper). Pleistocene. — Santa Barbara to San Pedro (Cooper): San Pedro; San Diego; Santa Barbara (Arnold). Pliocene. — San Diego well (Dall). Genus Amphissa H. £ A. ALlams. Shell bucciniform, longitudinally ribbed; spire elevated; aperture rather wide, enlarging below, and terminating in a wide anterior sinus; inner lip callous, plicate below; outer lip not thickened on margin, plicate within. Amphissa corrugata Reeve is a characteristic species. 235. Amphissa corrugata Reeve. Biiccinum corrugatum RvE., Icon. Conch., PI. IV, fig. no, 1846. Truncaria corrugata RvE., CPR., Brit. Assn. Rept. , 1863, p. 662. Comitiella {Amphissa) corrugata RvE., Cpr., Brit. Assn. Rept., 1866. Gaeb, Pal. Cal., Vol. II, p. 74, 1869. Amphissa corrugata RvE., Tryon, Man. Conch., Vol. V, p. 197, PI. LXIII, fig. 66, 1883. Cooper, 7th Ann. Rept. Cal. St. Min., 1S88, p. 228. Keep, West Coast Shells, p. 34, fig. 14, 1892. Shell small, solid, fijsiform; spire elevated; apex acute; whorls seven, slightly convex, with about eighteen to twenty rather wavy, slightly oblique, rounded, transverse ridges extending firom suture to suture; spiral ornamentation consists of numerous fine, raised lines in the interspaces between the transverse ridges; suture impressed, distinct; aperture rhomboidal, narrow; outer lip lirate within; inner lip incrusted, smooth; canal short, recurved; pillar spirally lined externally. Dimensions. — Long. 19 mm.; lat. 9 mm.; body-whorl 13.5 mm.; aperture 10 mm.; defl. 52 degrees. The Pliocene forms are much smaller than the one described above (a Pleisto- cene specimen). Carpenter mentions the shells as becoming dwarfed in deep water (40 fathoms). Rather common in Pliocene and lower San Pedro series at Deadraan Island; rare in upper San Pedro series at San Pedro, Los Cerritos, and Crawfish George's. Found also in the Pleistocene at the bath-house, Santa Barbara. Living. — Alaska to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa Bar- bara (Arnold). Pliocene. — San Diego well (Dall): San Pedro (Arnold). ( 31) Marcb 21, 19o;i. 242 CALIFOKNIA ACADEMY OF SCIENCES. 236. Amphissa ventricosa, sp. nov. Plate V, Fig. 11. Shell small, broadly fusiform; spire elevated; whorls five or six, evenly convex, with twelve or thirteen strong, rounded, transverse ridges; interspaces sculptured with prominent, regular, equi- distant, raised spiral lines, of which there are five or six on the penultimate whorl; suture deeply impressed, distinct; aperture semicircular; outer lip ventricose, thickened with row of teeth; inner lip smooth, incrusted; pillar straight; spirally sculptured on outside; no canal. Dime7isio7is. — Long. 12 mm.; lat. 6 mm.; body-whorl 8.6 mm.; aperture 6 mm.; defl. 43 degrees. Resembles A. bicolor somewhat, but distinguishable from this species by lack of canal, stronger ribs, and more convex whorls; distinguishable from other members of genus by thin shell, ventricose whorls, semicircular aperture and lack of differ- entiated canal. Dr. Dall examined the type and pronounced it a new species. Rare in lower San Pedro series of Deadman Island. The specimen figured is the type, which is from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). 237. Amphissa versicolor Ball. Amphissa versicolor Dall, Am. Jour. Conch., Vol. VII, 1872, p. iii. Tryon, Man. Conch., Vol. V, p. 197, PI. LXIII, fig. 67, 1883; Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213, PI. XX, fig. 9. Amphissa corrjigata Rye., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 228 (in part). Shell small, fusiform; apex acute; whorls seven, convex, slightly angular above; body-whorl slightly ventricose; surface ornamented with about fourteen rounded, obliquely transverse ridges, and several distinct, raised, spiral lines in the interspaces; suture quite deeply impressed; aperture sub- elliptical; outer lip slightly thickened by lirated ridges on inner side; inner lip incrusted, smooth; columella spirally sculptured externally; canal short, broad, recurved. Dimensions. — Long. 10.2 mm.; lat. 5 mm.; body-whorl 7 mm.; aperture 5 mm.; defl. 47 degrees. Distinguishable from A. corrugata by more ventricose body-whorl, relatively longer columella and shorter spire, more angulated whorls, deeper suture and less numerous but more oblique and larger transverse ridges. Specimen identified by Dr. Dall. Found in lower San Pedro series at Deadman Island, and upper San Pedro series at Crawfish George's, Los Cen-itos, and Deadman Island. Found also in the Pleistocene at Pacific Beach, San Diego. Living. — San Pedro (Dall). Pleistocene. — San Pedro; San Diego (Arnold). ARNOLD — THE PALEONTOLOGY AND STKAtlGEAPHY OF SAN PEDRO. 243 Family LXI. MURICID^. Genus Murex Linne. Shell ovate or oblong; spire prominent; whorls convex, crossed by three or more con- tinuous varices; aperture ending below in a canal, which is generally partly closed. Murex tenuispena Lara, is a characteristic species. Subgenus Chicoreus Montfort. Shell ovate-pyriform; varices foliated and sometimes spinose; canal short, curved, wide, nearly closed. Murex adustus Lam. is a characteristic species. 238. Murex (Chicoreus) leeanus Dull. Plate VII, Fig. 1. Murex (Chicore7is) leeanus Dall, Proc. U. S. Nat. Mus., Vol. XII, 1890, p. 329, PI. VII, fig. i. Shell large, strong, angular in outline; apex sharp; whorls five or six, angular, flat to con- cave above; each whorl ornamented with three varices, which extend out into long, rather sharp spines; the varices toward the apex fall short of completing a whole whorl, so that they are slightly spirally arranged; a faint node on angle between each pair of varices; surface sculptured with delicate squamose, spiral cinguli, with chiseled grooves between; suture deeply impressed, wavy; aperture elliptical; outer lip smooth; inner lip slightly projecting, smooth; canal long, narrow, slightly curved, covered; older termini of canal visible on pillar at left of canal. Dimensions. — Long. 55 mm.; lat. 43 mm.; body-whorl 47 mm.; aperture 17 mm. A large, showy shell, easily distinguishable by the long, sharp varical spines. Specimens identified by Dr. Dall. Rare in upper San Pedro series at San Pedro and Crawfish George's. The drawing of this species is a composite, and was made from two iraj^erfect specimens from the upper San Pedro series at San Pedro, which are now in the collection of Delos Arnold. Living. — Cerros Island, off Lower California (Dall). Pleistocene. — San Pedro (Arnold). 239. Murex (Chicoreus?) trialatus Sowerby. Murex trialatus Sby. , Proc. Zool. Soc, 1840, p. 143. Tryon, Man. Conch., Vol. II, p. 113, PI. XXXIV, fig. 372, 1880. Murex califorjiicus Hds., Proc. Zool. Soc, 1843, p. 128. Voyage Sulphur, PI. Ill, figs. 9 and 10, 1844. Tryon, Man. Conch., Vol. II, p. 113, PI. XXXIV, fig. 375; PI. XXXV, fig. 287, 1880. Muricidea californica Hds., Cpr., Brit. Assn. Rept., 1863, p. 663. Gabb, Pal. Cal., Vol. II, p. 69, 1869. Shell small, fusiform; spire elevated, subacute; whorls five, convex; body-whorl over three- fourths length of shell; varices three, thick and rounded, elevated on angle of whorl to sharp, 244 CALIFORNIA ACADEMY OF SCIENCES. prominent nodes; a single, less prominent, rounded node on angle between each pair of varices; spiral sculpture of fine raised lines, with fine incremental lirute in the interspaces; aperture ovate; canal long, narrow, slightly recurved, and generally covered by overgrowing sides; lower part of columella slightly widened; outer lip thickened by varix, smooth inner surface; inner lip slightly raised and smoothly enameled. Dinie7isions. — Long. 38 mm.; lat. 21.5 mm.; body whorl 30 mm.; aperture 22.5 mm.; canal 1 1 mm. ; defl. 60 degrees. Hare in upper San Pedro series at San Pedro, Deadman Island, and Craw- fish George's. Living. — Baulinas Bay to San Diego (Carpenter) : Lower California (Hemphill ) . Pleistocene. — San Pedro (Arnold). Subgenus Pteronotus Sivainson. Shell triangular; varices fin-like or foliated; canal moderate, closed, somewhat curved. Murex trigonulus Lam. is a characteristic species. 240. Murex (Pteronotus) festivus Hinds. Murex festivus Hds., Proc. Zool. Soc, 1843, p. 127; Voyage Sulphur, p. 9, PI. Ill, figs. 13 and 14, 1844. Tryon, Man. Conch., Vol. II, p. 116, PI. XXXV, fig. 383, 1880. Pteronotus festivus Hds., Cpr., Brit. Assn. Rept., 1863, p. 663. Gabb, Pal. Cal., Vol. II, p. 70. 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 261. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part I, 1890, p. 142. Keep, West Coast Shells, p. 22, fig. 3, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 216. Shell of moderate size, fusiform; spire elevated, short; whorls si.x, subangulate, crossed by three prominent, reflexed, frill-like varices; a single rounded node between each set of varices; numerous spiral lines, which are almost obsolete, ornament the intervarical spaces; suture deeply impressed; aperture pyriform; outer and inner lips smooth; canal long, narrow, slightly curved; columella squamose on outside, widened slightly. Dimensions.- — Long. 40 mm.; lat. 21 mm.; body-whorl 31 mm.; aperture, not including canal, 12 mm.; canal 11 mm.; defl. 65 degrees. This species is characterized by the sharp, frill-like varices said by Dr. Dall to resemble quite closely /". (le./^^i/iy Gabb, of tlie Miocene of San Domingo and Hayti, and the Pliocene of Florida. Rare in the lower San Pedro series at Deadman Island; not uncommon in the upper San Pedro series at Deadman Island, Crawfish George's, San Pedro and Los Cerritos. Found also in the Pleistocene at Spanish Bight, San Diego. Living. — San Pedro to San Diego; Lower California (Cooper). rieistocene. — Santa Barbara; San Diego (Cooper): San Pedro; San Diego (Arnold). Subgenus Pterorhytis Conrad. Varices wing-like; aperture usually dentate within the outer lip, with a produced tooth near its base. Type, Murex nuttalli Conrad. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 245 241. Murex (Pterorhytis) foliatus iiartijn. Cerostoma foliaiufn Martvn, Univ. Conch., No. 66, PI. XXIV, fig. i, 1784. Cpr., Brit. Assn. Rept, 1863, p. 663. Keep, Common Sea Shells, PI. XIV, fig. 5, 1881; West Coast Shells, p. 27, 1892. Murex foliatus Mart., Tryon, Man. Conch., Vol. II, p. 113, PI. XXXIV, figs. 370, 371, 373, 1880. Pterorhytis foliahis Mart., Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 24. Shell small, broadly fusiform, with extended varices; spire elevated, subacute; whorls three to four; varices three, widely expanded, foliated on anterior side; one prominent node on convex surface of whorl between each set of varices; aperture subovate, with smooth outer and inner lip; canal long, narrow, expanding anteriorly, generally covered by overgrowing lips. Dimensiotis. — Long. 35 mm.; lat. 21 mm.; body-whorl 26.5 mm.; aperture 21 mm.; canal 10 mm. Distinguislmble by the wing-like, foliated varices. The specimen tleseribed was too poor to figure. Rare in the upper San Pedro series of San Pedro; one specimen found. Living. — Vancouver to Oregon (Carpenter): Sitka to Santa Barbara; Asia (Cooper). Pleistocene. — San Pedro (Arnold): Puget Sound; San Diego; Santa Barbara Islands (Carpenter): San Joaquin Bay, Orange County (Bowers). 242. Murex (Pterorhytis) nuttalli Conrad. Cerostoma nuttalli Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 264, PL XX, fig. 22. Cpr., Proc. Zool. Soc, 1856, p. 229; Brit. Assn. Rept., 1863, p. 663. Tryon, Struct, and Syst. Conch., Vol. II, p. 105, PL XLIII, fig. 8, 1883. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 233. Keep, West Coast Shells, p. 26, fig. 8, 1892. Pterorhytis nuttalli CoN., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 215. Shell of medium size, heavy, thick; spire elevated, subacute; whorls four, convex, each with three prominent varices, which are rather smooth behind, but showing their lamellar structure in front; each varix is connected with the analogous vari.x on the preceding whorl, but the varices being slightly less than one-third of a revolution apart cause the radiating ridges formed by the connected varices to be spirally twisted; intervarical spaces prominently spirally ribbed, the ribs extending on to the backs of the varices; seven or eight prominent spiral ribs on the body-whorls; aperture ellip- tical; outer lip with eight or nine internal teeth, each corresponding to one of the external sulcations of the body-whorl; sometimes with prominent tooth near anterior portion of outer lip; inner lip smooth; canal rather short, covered; lower portion of columella expanded, rough, subpunctate. Dimensions. — Long. 65 mm.; lat. 34 mm.; body-whorl 50mm.; aperture 25 mm.; canal 14 mm. This species may be only a variety of P. foliatus Mart. It is distinguishable from the latter species by the greater prominence of its spiral sculpture, and it.':^ lower varices. Rare in upper San Pedro series at Deadman Island and Los Cerritos. Living. — Paulinas Bay to San Diego (Cooper). Pleistocene. — San Pedro (Arnold): San Diego (Cooper). 246 . CALIFORNIA ACADEMY OF SCIENCES. 243. Murex (Pterorhytis) monoceros Soiverby. Murex monoceros Sby., Proc. Zool. Soc, 1840, p. 143. Tryon, Man. Conch., Vol. II, p. 115, PI. XXXV, figs. 388, 389, 1880. Muricidea (^Phyllonotus) paucivaricata Gabb, Pal. Cal., Vol. II, p. 43, PI. XIV, fig. i, 1869 {fide Tryon). Muricidea paucivaricata Gabb, Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 252 {^fide Tryon). Shell moderate in size, fusiform; spire nearly as long as aperture; whorls seven, subangulated, bearing eight or nine large, longitudinal ribs which develop into prominent nodes on the angle; suture irregular, appressed, distinct; aperture ovate; canal rather short, narrow, recurved, and often overgrown by two lips; outer lip thickened, denticulated with four sharp teeth; inner lip slightly projecting, smooth, incrusted; columella widened; varices two or three, never prominent, sometimes obsolete; numerous small revolving ribs crossed by small squamose plates; body-whorl sometimes ornamented with five or six, quite prominent, rounded, spiral ridges. Dimensio7is. — Long. 46 mm.; lat. 23 mm.; body-whorl 32 mm.; aperture, including canal, 26 mm.; canal 9 mm.; defl. 50 degrees. Distinguishable from M. calif ornica by denticulated outer lip, lack of varices, thicker shell, and generally larger size. Originally described from Pleistocene specimen. Rare in upper San Pedro series of San Pedro. Living. — Lower California? Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro (Arnold). Genus Monoceros Lamarck. Shell ovate; last whorl large; spire rather elevated; aperture semilunar; inner lip wide and flattened; outer lip crenated, with a prominent tooth usually at the forepart. Monoceros lugubre Sowb. is a characteristic species. 244. Monoceros engonatum Conrad. Monoceros engonatum CoN., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 264, PI. XX, fig. 17. Cpr., Brit. Assn. Rept., 1863, p. 663. Gabb, Pal. Cal, Vol. II, p. 75, 1869. Tryon, Man. Conch., Vol. II, p. 195, PI. LXI, figs. 304, 1880. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 251. Keep, West Coast Shells, p. 29, fig. 10, 1S92. Willi- amson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 214. Monoceros unicarinatum RvE., Icon. Conch., Sp. i. Shell of medium size, fusiform; whorls six, angular, flattened to concave above and below; spirally sulcate, sulci with tranverse lamellar strite; suture deeply appressed, distinct; aperture sub- elliptical; outer lip effuse, dentate within; inner lip slightly flattened, smooth; canal deep, narrow, recurved; pillar twisted, squamose. Dimensions.- — -Long. 40 mm. ; lat. 20 mm.; body-whorl, 30.5 mm.; aperture 24 mm.; defl. 55 degrees. This is a variable species. Specimens showing the scaly surface of var. spiratum grade over into the smooth form; the sharp-keeled forms merge into those which approach very near to M. lajnlloides. Some specimens have thin and smooth ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDEO. 247 outer lips, while others are strongly dentate. Of fifty specimens from the San Pedro Pleistocene only three have the characteristic tooth developed, thus showing that in these earlier forms this distinguishing characteristic was only occasional. The scaly specimens are generally the strongest keeled. This latter form is the var. spiratum of Blainville. Found in all of the lower and upper San Pedro series localities in the vicinity of San Pedro. Found also in the Pleistocene at Barlow's ranch, Ventura; and at Pacific Beach, San Diego. Living. — Baulinas Bay to San Diego (Cooper). Pleistocene. — San Pedro; San Diego (Cooper) : Lake Merced, San Mateo County; San Pedro; San Diego; Ventura (Arnold). 245. Monoceros lapilloides Conrad. Purpura {Monoceros) lapilloides Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 265, PL XX, fig. 18. Mo7ioceros lapilloides Con., = M. punclaium Gray, -f- M. brevidens Con. {fide Cpr., Brit. Assn. Rept., 1863, p. 663). Keep, West Coast Shells, p. 28, fig. 9, 1892. Cooper, Bull. No. 4, Cal. St. Min. Bureau, 1894, Part 3, p. 28. Shell of medium size, purpuroid-shaped; spire elevated; apex subacute; whorls four, very slightly conve.x; surface ornamented with nearly obsolete spiral cinguli and nearly obsolete, irregular, wavy, transverse ridges; suture impressed, indistinct; aperture subovate; outer lip thickened, dentate; inner lip flattened, smooth; canal short. Dime7isions. — Long. 20.5 mm.; lat. 13 mm.; body-whorl 18 mm.; aperture 14 mm.; defl. 67 degrees. The specimen described shows the reddish color of the live shells. Distin- guishable from M. engonatum by much shorter spire, broader and shorter pillar, and much less angular whorls; distinguishable from Purpura saxicola by relatively larger spire, narrower aperture, dentate outer lip and spiral cinguli. Bare in uj^per San Pedro series of San Pedro; one specimen. Living. — Santa Barbara to San Diego (Carpenter): Monterey (Cooj^er). Pleistocene. — San Pedro (Arnold): Ventura County (Bowers). Genus Chorus Gray. Shell laminately varicose; spinose on the shoulder; canal rather long; outer lip with a spine as in Monoceros. Tyjie, Chorus helcheri Hinds. 246. Chorus belcheri Hinds. Murex belcheri Hds., Proc. Zool. Soc, 1843, p. 127; Voyage Sulphur, PI. II, figs. 1-3, 1S44. Pfeiffer, Nov. Conch., Ser. II, p. 35, PI. X, figs. 6, 7. Chorus belcheri Hds., Cpr., Brit. Assn. Rept., 1863, p. 663. Tryon, Man. Conch., Vol. II, p. 198, PI. LXI, fig. 309, 1880; Syst. Conch., Vol. II, p. 114, PI. XLV, figs. 43, 44, 1883. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 235. Keep, West Coast Shells, p. 25, fig. 7, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 216. 248 CALIFORNIA ACADEMY OF SCIENCES. Sliell large, broadly fusiform; spire slightly elevated; whorls five, sharply angulated, with eight or nine nearly obsolete varices which rise to prominent blunt nodes or spines on the angle of whorl; incremental lines prominent; spiral liration on upper whorls; suture impressed, distinct; aperture ovate; outer lip not thickened, effuse; inner lip incrusted; columella widened; umbilicus perforate; canal long, narrow, curved backwards. Dime7isions. — Long. 90 mm.; hit. 62 mm.; body-whorl 78 mm.; aperture 40 mm.; canal 25 mm.; defl. 95 degrees. A beautiful shell, one of the largest gastrojiods found in this fortnation. Rare in upjier San Pedro series at Crawfish George's, Los Cerritos, and San Pedro. Found also in the Pleistocene at Barlow's ranch, Ventura. Living. — Catalina Island to San Diego; Lower California (Cooper) : Sitka (Carpenter): Japan (Tryon). Pleistocene. — San Pedro (Cooper; Arnold): Ventura (Arnold). Pliocene. — San Diego well (Dall). Genus Eupleura //. & A. Adams. Shell ranelliform, with a pair of lateral varices, one on either side, and intermediate smaller varices; aperture dentate within. Eupleura caudata Say is a characteristic species. 247. Eupleura muriciformis Broderip. Plate IX, Fig. 16. Ranella muriciformis Brod., Proc. Zool. Soc, 1832, p. 179. Rve., Conch. Icon., Ranella, PI. VII, fig. 34, 1844. Ranella plicaia Rye., Proc. Zool. Soc, 1844, p. 13S; Conch. Icon., Ranella, PI. VII, fig. 33, 1844. Ranella triquetra RvE., Proc. Zool. Soc, 1844, P- I39i Conch. Icon., Ranella, PI. VII, fig. 41, 1844. Cpk., Brit. Assn. Rept., 1863, p. 667; 1856, p. 201. Gabb, Pal, Vol. II, p. 73, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 262. Eupleura muriciformis Brod., Cpr., Brit. Assn. Rept., 1856, p. 182. Trvon, Man. Conch., Vol. II, p. 168. PL XXXIX, figs. 501, 502, 504, 505, 1880. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part I, 1890, p. 145. Eupletira muriciformis (var.?) unispinosa Dall, Proc U. S. Nat. Mus., Vol. XIV, 1891, p. 174, PL VI, fig. 5. Shell of medium size, quite broadly fusiform, solid; spire elevated; whorls five, subangular at lower one-third, concave to straight above, convex below; whorls crossed by varices at every two- thirds revolution, the two varices on the body-whorl and the ne.\t varix posterior to these are prominent, the others being obsolete in most cases; the varices are generally thin, webbed, and with six obsolete spines; the spine at the shoulder is the most prominent, but the second spine, counting forward, is the one corresponding to the axis of the intervarical nodes; the web between the shoulder spine and the suture is bent forward; spiral ridges correspond to each spine; four nodes on angle of whorl between each pair of varices; suture deeply impressed, distinct; aperture elliptical; outer lip thickened by six dentiform calluses, one each between each pair of external spiral ridges; canal long, narrow, nearly straight. Dimensions. — Long. 25.5 mm.; lat. 14 mm.; body- whorl 20.5 mm.; aperture, including canal, 17.5 mm.; canal 7 mm.; defl. 70 degrees. ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 249 The prevailing t^ype of the San Pedro fossil specimens does not correspond exactly to any of tlie descriptions of the living varieties of this species as given by Dr. Dall in the paper cited above. It comes nearest to var. unispinosn, differing from that form by having a straight canal. The name var. pleistocenensis is suggested for the San Pedro fossil foi'm. Rare in the upper San Pedro series of San Pedro; one specimen from lower San Pedro series at Deadman Island. Found also in the Pleistocene at Twenty- sixth Street, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — California to Venezuela (Dall). • Pleistocene. — San Pedro (Arnold): San Diego (Dall; Cooper; Arnold): Pacific coast of Lower California; head of the Gulf of California (Dall). 248. Eupleura muriciformis var. curta, var. nov. Plate VIII, Fii:. 9. Shell small, broadly fusiform; whorls four, angular, flat above, convex below; two sharp spiral ridges on upper whorls, si.x on body-whorl corresponding to obsolete spines on varix; one prominent varix on body-whorl, other varices obsolete; whorls crossed by prominent, narrow, rounded ridges, of which there are twelve on the penultimate whorl; aperture elliptical; outer lip thickened by a row of six denticles; inner lip smooth, projecting; canal short, narrow. Dimensions.- — Long. 15 mm.; lat. 10 mm.; body-whorl 11 mm.; aperture, including canal, 9.5 mm.; canal 2.2 mm.; defl. 65 degrees. Differs from E. muricifonim in having obsolete varices, transverse ridges instead of nodes, much shorter canal, and in general much stronger sculpture. The type, which is figured, is from the upper San Pedro series at San Pedro, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). Genus Trophon Mont fori. Varices numerous, lamelliform or laciniated; spire prominent; aperture ovate; canal open, usually turned to the left; shell white, often dark colored within the aperture. Tro'phon clatludtm^ Linn, is a characteristic species. Subgenus Boreotrophon Fischer. 249. Trophon (Boreotrophon) cerritensis, sp. nov. Pl.\te VI, Fig. 6. Shell of medium size, elongate-fusiform, heavy; whorls six, angular, with angle in middle, crossed by about eighteen strong, transverse ribs; lower portion of whorls ornamented with two or three strong, spiral ridges, one of which- is on the angle, the two systems of ridges giving a can- cellated surtace; body-whorl and columella cancellated; suture deeply impressed, distinct; aperture ( il ) Maivb 24. 1903. 250 CALIFORNIA ACADEMY OF SCIENCES. ' elliptical; outer lip thickened, smooth within; iiim r lip incrusted, smooth; columella only faintly squamose, curved and slighdy twisted; canal rather short, narrow. Dimensions. — Long. 33 mm.; lat. 15 mm.; body-whorl 23 mm.; aperture, including canal, 18 mm.; canal 7 mm.; defl. 44 degrees. The largest of the Troplwns so far found in this locality. The adult of this shell resembles var. prrecur^ior, but is distinguishable from that species by its larger size, heavier shell, more prominent spiral ridges, pro23ortionally shorter canal, and in having the angle near the middle of the wiiorl, rather than posterior to the middle; distinguishable from 2\ ^tiuirti by heavier shell, more numerous and much heavier, lower and more rounded, transverse ridges, shorter canal, and by having the angle in the middle of the whorl. The young of T. cerritensis resembles 7\ i^edroana some- what, but may be distinguished from that species by its heavier shell, more depressed outline and much shorter canal. An adult found at Los Cerritos has fewer transverse ridges and a higher angle than the type. Type from lower San Pedro series of Deadman Island. Said by Dr. Dall to be near 2\ craticnlattis Fabricius. One adult specimen (type) and five juniors found in lower San Pedro series at Deadman Island; one specimen from Los Cerritos in ujiper San Pedro series. The specimen figured is the type, whicii In from the lower San Pedro series at Deadman Island, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). 250. Trophon (Boreotrophon) gracilis Perry. Plate VI. Fig. 8. Polyplex gracilis Perry, Conch , PI. IX, fig. 4. Trophon 7n7tllicostatus (noi oiK^CH.) Gxhh. Pal. Cal., Vol. II, p. 70, 1S69 (in part). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 26S (in part). Shell of medium size, lusilorm; sp're elevated; whorls five or si.x, sharply angular, crossed by eight or nine frill-like varices, which fle.x forward and are only slightly ccjronate on angle; surface smooth; suture deeply impressed, giving tabulate appearance to upper part of whorl; apertura elliptical; outer lip effuse, smooth within; inner lip smooth; columella long, slightly twisted; canal long, narrow, recurved. Dimensions. — Long. 26 mm.; lat. 13 mm.; body-whorl ig 5 mm ; aperture 16.2 mm.; canal 7.7 mm.; defl. 62 degrees. Distinguishable by frill-like varices and lack of spiral sculpture. Specimens identified by Dr. Dall. This species is the T. mii Uicostatus of most western col- lectors. It differs from that species in having fewer, but more prominent varices, and in being a broader shell. Rare in Pliocene and lower San Pedro series of Deadman Island. Found also in the Pleistocene at bath-house, Santa Barbara. The specimen figured is from the Pliocene of Deadman Island, and is now in the collection of Delos Arnold. Livvir/. — Circumpolar; Sitka to Monterey (Cooper). Pleistocene. — Santa Barbara (Cooper; Arnold): San Pedro (Arnold). Pliocene. — San Pedro (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATlGlUPHY OF SAN PEDRO. '251 251. Trophon (Boreotrophon) multicostatus Eschseholtz. Pi.ATK VI, Fig. 9. Miirex mullicostahis EscH., Zool. Atlas, \'ol. II, p. 11, PL IX, fig. 4, 1829. Kuster, Afurex, p. 45, PI. XVI II, fig.s. 5 and 6, 1837. Trophon inullicostaius EscH., H. & A. Adams, Gen. Rec. Moll., Vol. i. p. 77. Cpr., Rrit. Assn. Rept., 1863, p. 663 (in jiart). Tryon, Man. Concli., Vol. II, p. 141, PI. XXXI, fig. 316, 1880. Cooper, 7tli Ann. Rept. Cai. St. Min., 18S8, p. 269 (in part). Keep, West Coast Shells, p. 21, 1S92 (in part). Shell small, tiisiform; whorls five, angular above, with twelve to fourteen raised varices; no spiral sculpture; aperture subelliptical; outer lip not effuse; inner lip smooth; canal short, slightly curved. Dimensions. — Long. 10.5 mm.; lat. 4.5 mm.; body-whorl 7 mm.; aperture, including canal, 5 mm.; canal i mm.; defl. 40 degrees. The shell described is a small one. Distinguishable from T. (jvacilh by having larger number of varices, le.ss prominent varices, more slender shell, a less effuse outer lip, and less sharply angulated whorls. Identified as "7'. multicostatus var.?" by Dr. Dall. Rare in the lower San Pedro series at Deadman Island, and in upper San Pedro series at San Pedro. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Sitka to Monterey; circumpolar (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). 252. Trophon (Boreotrophon) pedroana, sp. nov. Plate VL Fig. P2. Shell small, elongate-fusiform, thin; spire elevated, acute; whorls si.x, convex, with very slight angle about one-third width from posterior margin; body-whorl slightly ventricose; whorls ornamented with about fourteen slightly raised, rounded transverse ridges, and two faint spiral ridges, one of which is on the angle of whorl; suture deeply impressed, distinct; aperture semiovate; outer lip thin, not effuse; inner lip smooth; columella long and slender, smootli; canal long, narrow, nearly straight. Dimensions. — Long. 12 mm.; lat. 4.8 mm.; body-whorl 9 mm.; aperture, including canal, 7 mm.; canal 3 mm.; defl. 35 degrees. The thinnest, most delicate of the Irophons of this locality. Distinguishable from var. pr(ecitrsor by thinness, less angulation of whorl.s, less prominence of sculpture, and simple outer lip; distinguishable from T. !., Cpr., Brit. Assn. Rept., 1863, p. 660. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 255. Keep, West Coast Shells, p. 49, fig. 30, 1892. Scala (Opalia) borealis CpR., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 210. Shell small, turreted, thick; apex generally decollated; whorls seven, only slightly convex; varices eight, rounded, thick, prominent, and forming radiating ridges from the apex; suture im- pressed, distinct; body-whorl squarely angulated at base, with keel on angle; base flat, smooth; aperture subovate; outer lip thin, effuse; inner lip only slightly incrusted. Dimensions. — Long. 15 mm.; lat, 6 mm.; defl. 22 degrees. The specimens described were identified by Dr. Dall. Rare in upper San Pedro series of San Pedro; two specimens. Living. — Karatschntka; Straits of Fuca to San Diego (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 267 280. Opalia crenatoides Carpenter, var. insculpta Carpenter. Opalia (? creyiatoides) var. insadpta CPR., Brit. Assn. Rept. , 1863, p. 660; Ann. & Mag. Nat. Hist., 3rd Series, Vol. XVII, 1866, p. 277. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 255. Shell of medium size, elongated, thick, milk-white; spire elevated, with blunt apex; whorls six, convex; first and second post-nuclear whorls more convex than the remaining whorls, angulated, nearly smooth; last four post-nuclear sharply and strongly angulated above, flattened along middle, and quite abruptly contracted at base; whorls ornamented with twelve to fourteen radiating trans- verse ribs, which are obsolete on the sides of the whorl, faintly developed at the base, and strongly developed on the top of the whorl, where they are appressed against the antecedent whorl, and appear like nodes on the angle of the whorl; a faint sutural riblet is sometimes noticeable on the base of the whorl; above this sutural riblet are faint holes, corresponding to the intercostal spaces; fine incremental striations are visible over the whole surface of the shell; the base of the body-whorl, just below the angle, is ornamented with a prominent, wide, elevated rib; aperture elliptical; outer lip thickened, rounded, slightly expanded at columella; this lip is finely, concentrically striated; inner lip rounded, smooth. Dimensions. — Long. 16.4 mm.; lat. 8.3 mm.; body-whorl 9.9 mm. This species is distinguishable by its broad form and sharj^ly angular whorls, which are prominently sculptured above, with obsolete sculpture on the sides of the whorl. Carpenter's type specimen was a jwst-Pliocene fossil from Santa Barbara. Rare in the upper San Pedro series at Deadman Island. Living. — Santa Cruz to Santa Barbara (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). [S. D.] Opalia varicostata Stearns. Opalia varicostata Stearns, Proc. Phil. Acad. Nat. Sci., 1875, p. 463, PI. XXVII, figs. 2-5. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 255. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2, 1892, p. 245. Shell elongated-conical, turreted, tapering, solid, imperforate; aperture ovate; peristome continuous, thickened; dingy to clear white; suture well defined; whorls united, exceedingly variable in convexity and altitude; specimens all decollate or truncated, equally solid, though varying in length from 20 to 60 millimeters, showing four and one-half whorls within the first measurement to five in the latter; longitudinal ribs nine to twelve, varying in number, prominence and regularity, as well as in obliquity and thickness; suture more or less waved, dependent upon the prominence of the ribs, which terminate anteriorly at and join a transverse (spiral) rib at about the middle of the basal whorl. Dimeyisions of a Rather Small Specimen. — Long. 34 mm.; lat. 14.5 mm.; body-whorl 17 mm.; aperture 9 mm. This magnificent but variable species has so far been reported only from the Pliocene of San Diego, where it is quite common. Pliocene. — San Diego (Hemphill; Stearns; Arnold). 268 CALIFORNIA ACADEMY OF SCIENCES. Superfamil}- GYMNOGLOSSA. Family LXIII. EULIMID.E. Genus Eulima Risso. Shell small, white, and polished; slender, elongated with numerous level whorls; spire often curved to one side; obscurely marked on one side by a series of periodic mouths which form promi- nent ribs internally; apex acute; aperture oval, pointed above; outer lip tiiickened internally; inner lip reflected over the pillar, not umbi Heated. Eulima tortuosa Adams is a characteristic species. 281. Eulima falcata Carpenter. Plate IX, Fig. 15. Eulima falcata Cpr., Proc. Zool. Soc, 1865, p. 280. Shell small, elongated, thin, white, glossy; spire verj' acute, curved into scythe-shape; whorls ten, flat; suture indistinct, not impressed; body-whorl subangular at base; base elongated; aperture pyriform, seemingly appressed to side of shell out of its normal position; outer lip acute and rounding; inner lip concave. Ditnensions. — Long. 6.5 mm.; lat. 3 mm.; body-whorl 3 mm.; aperture 2.5 mm.; defl. 30 degrees. Distinguishable from E. jnicans by subangulated body-wliorl, eccentric nperture and curved spire; distinguishable from E. hastnta by curved spire and more eccentric aperture. The specimens described were identified by Dr. Dall. One specimen each from the lower San Pedro series at Deadman Island and the upper 8an Pedro series at San Pedro. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Living. — Acapulco (Carpenter) . Pleistocene. — San Pedro (Oldroyd; Arnold). 282. Eulima hastata Sowerby. Plate IX, Fio. 9. Eulima hastata Sbv, , Proc. Zool. Soc, 1834, p. 7. Cpr., Brit. Assn. Rept , 1856, p. 335. Tryon, Man. Conch., Vol. VIII, p. 273, PI. LXIX, t^g. 39, 1886. Shell small, slender, turreted; apex acute; whorls nine, fiat, smootli; suture indistinct, not impressed; body-whorl angular below, short; aperture suboval, abruptly truncated in front. Dimensio7is. — Long. 7.4 mm.; lat. 2.5 mm.; body-whorl 3.1 mm.; aperture 2 mm.; defl. 22 degrees. Distinguishable by the short, angular base, and short, truncated aperture. In other respects like E. micans. Specimens identified by Dr. Dall. Four found in upper San Pedro series at San Pedro; and one in the lower San Pedro series at Deadman Island. Found in the Pleistocene at Barlow's ranch, ARNOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDRO. 2G9 Ventura; and at Spanish Bight, San Diego. The specimen figured is from the upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold. Living. — Gulf of California; Ecuador (C'arpenter). Pleistocene. — San Pedro; Ventura; San Diego (Arnold). 283. Eulima micans Carpenter. Plate IX, Fig. 12. Eulima micayis Cpr., Brit. Assn. Rept., 1863, p. 659. Reeve, Conch. Icon., p. 33, 1865. Tryon, Man. Conch., Vol. VIII, p. 272, PI. LXIV, figs. 29, 30, 1886. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 240. Keep, West Coast Shells, p. 50, fig. 32, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 209. Shell small, turreted, glossy; apex acute; whorls ten, flat; body-whorl convex; suture distinct, not impressed; aperture elongate-ovate; outer lip thin, rather arcuate; inner lip slightly incrusted. Dimensions. — Long. 12 mm.; lat 3.2 mm.; defl. 25 degrees. Distinguishable from E. falcatn by straight spire and less bulging outer lip; distinguishable from E. hastata by even convexity of body-whorl. The specimen.s described were identified by Dr. Dall. Found in the lower San Pedro series at Deadman Island and San Pedro, and in the upper San Pedi'o series at Crawfish George's, Los Cerritos, and San Pedro. The specimen figured is from the lower San Pedro series at Deadman Island, and is now in the collection of Delos Arnold. Found also in the Pleistocene at Barlow's ranch, Ventura, and at Spanish Bight, San Diego. Living. — Straits of Fuca to San Diego (Cooper). Pkiiart of outer lip, and plicated columella. Found in Pliocene of Deadman Island; one specimen from lower San Pedro series of Deadman Island. Living. — Monterey (Cooper): San Pedro (Raymond). Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold). Pliocene. — San Pedro (Arnold). Genus Phorcus Risso. Shell conoidal, umbilicated; umbilicus cylindrical or infundibuliform; whorls frequently tuber- culated above and with channeled suturt-; ct)luiiiella sometimes terminating in a tubercular tooth. Phoycus magiix Linn, is a characteristic species. 379. Phorcus pulligo Martyn. Trochus pulligo Mart., Univ. Conch., PL LXXVI, 1784. Philippi, Conch. Cab., p. 84, PI. XV, fig. 3. Fischer, Coq. Viv., p. 232, PI. LXXX, fig. i. Phorcus pulligo Makt., Cpr., Brit. Assn. Rept., 1863, p. 653. Cooper, 7th Ann. Rept. Cal. vSl. Min., 1888, p. 259. Chlorostoma pulligo Mart., := C. niarcidus Gld. {^fide Tryon, Man. Conch., Vol. XI, p. 171, PI. XXVI, figs. 23, 24, 25, 1889). Shell broadly conical; whorls five, flat, but somewhat obsoletely ribbed or bluntly nodose in most specimens; surface shows extremely oblique lines of growth; suture distinct but not much impressed; base flat and smooth, except for faint incremental lines; aperture subovate; lips not thickened; umbilicus smooth, round and effuse. Dimensioyis. — Alt. 18 mm.; lat. 22 mm.; defl. 78 degrees. This shell is often confused with Chlorostoma montereyi, but may be distin- guislied from that species by its gradually expanding umbilicus, greater deflection, and lack of spiral sculpture. Specimens of this species were identified by Dr. Dall. Rather common in the upper San Pedro series of Crawfish George's. The specimen figured is from the upper San Pedro series at Crawfish George's, and is now in the collection of Delos Arnold. Living. — Sitka to San Pedro (Cooper.) Pleistocene. — San Pedro; San Diego (Cooper): San Pedro (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 329 Genus Calliostoma Suuinson. Shell trochiform, conical, not unibilicated; last whorl angulated and usually ribbed at the periphery; aperture quadrangular; columella simple, oblique, often ending in a tooth in front. Calliostoma zizyphinvm Linn, is a ciiaracteristic species. 380. Calliostoma annulatum Martyn. Trochus annulatiis Mart., Univ. Conch., Vol. I, fig. 33, 1784. Philippi, Conch. Cab., p. 11, PL III, figs. 3, 4. Zizyphiniis annulatus Mart., A. Ads., Proc. Zool. Soc, 1851, p. 164. Gray, Dieffenbach's N. Zealand, p. 237, No. 72. Calliostoma annulahmi Mart., Cpr., Brit. Assn. Rept., 1863, p. 652. Gabb, Pal. Cal., Vol. II, p. 83, 1S69. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Tryon, Man. Conch., Vol. XI, p. 363, PI. LXVII, fig. 43, 1889. Keep, West Coast Shells, p. 79, fig. 64, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, PL XXII, fig. 2. Shell conical; whorls seven, slightly angulated in center, and ornamented with sharply nodose spiral ridges which increase by intercalation from two on third whorl to seven or eight on body-whorl; suture deep, distinct; body-whorl acutely angulated at base; base nearly flat, ornamented with, numerous smooth, rounded spiral lines; aperture subquadrate; columella nearly straight, thickened. Dimensions. — Alt. 17 mm.; lat. 16 mm.; defl. 67 degrees. Distinguishable by slightly angulated whorls, nearly equally prominent nodose ridges, and nearly straight cohimella. Quite rare in the upper San Pedro series of San Pedro. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro (Arnold). Pliocene. — San Diego well (Dall). 381. Calliostoma canaliculatum Martyn. Trochus canaliculatus Mart., Univ. Conch., Vol. I, fig. 32, 1784. Zisyphinus canaliculatus Mart., Gray, Dieffenbach's N. Zealand, p. 327. Reeve, Conch. Icon., fig. 18. Calliostoma canaliculatujn Mart., Cpr., Brit. Assn. Rept., 1863, p. 652. Gabb, Pal. Cal., Vol. II, p. 83, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Tryon, Man. Conch., Vol. X, PL XLI, fig. 34, 1888; VoL XI, p. 361, PL LXVII, fig. 49, 1889. Keep, West Coast Shells, p. 80, fig. 65, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, PL XXII, fig. 6. Shell conical; whorls six, flat, ornamented with very prominent rounded, spiral ridges, two on the third and fourth whorls, and then increasing by intercalation until the body-whorl in some specimens has five or six prominent ridges, with a less number of auxiliary riblets in between; suture deeply impressed, forming a canal; aperture subquadrate; base flat, and ornamented in the same way as the whorls; lip as in C. costatinn. Dimensions. — Long. 19 mm.; lat. 20 mm.; defl. 67 degrees. Distinguishable by flat whorls, sutural canal, and few large spiral ridges. ( 42 ) April 29, 1903. 330 CALIFOKNIA ACADEMY OF SCIENCES. Rare in the Pliocene of Deadman Island, and in the lower San Pedro series of Deadman Island and San Pedro; common in the upper San Pedro series of Deadman Island, San Pedro, Los Cerritos, and Crawfish George's. Found in the Pleistocene at Spanish Bight, and in the Pliocene at Pacific Beach, San Diego. Living. — Straits of Fuca to San Diego (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego (Arnold). Pliocene. — San Pedro; San Diego (Arnold). 382. Calliostoma costatum Martyn. Trochus costatus Mart., Univ. Conch., PI. X, fig. 3, 1784. Philippi, Conch. Cab., p. 275, PI. XL, fig. 8. Calliostoma costatum Mart., Cpr., Brit. Assn. Rept., 1863, p. 652. Gabb, Pal. Cal., Vol. II, p. 83, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Tryon, Man. Conch., Vol. XI, p. 362, PI. XVI, figs. 6, 9; PI. XVIII, fig. 16, 1889. Keep, West Coast Shells, p. 81, fig. 66, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, PI. XXII, fig. I. Zizyphinus filostis Wood, Reeve, Conch. Icon., fig. 27. Shell turbinated, thick; whorls five, convex, and ornamented with about eight, almost equally prominent, spiral ridges; fine oblique incremental lines visible on most specimens; suture deeply impressed; base slightly convex, ornamented same as whorls; outer lip slightly effuse; columella thickened and incrusted. Dimensions. — Alt. 22 mm.; hit. 20 mm.; defl. 70 degrees. Distinguishable by the even convexity of the whorls, numerous, comparatively smooth, spiral ridges, and thickne.ss of the shell, which is unusual for a member of this genus. Rare in the lower San Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series of Crawfish George's, Los Cerritos, and San Pedro. Found in the Pleistocene at Pacific Beach, San Diego. Living. — Sitka to San Diego (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego (Arnold). Pliocene. — San Fernando, Los Angeles County (Cooper). 383. Calliostoma gemmulatum Carpenter. Calliostoma gemmulatum Cpr., Brit. Assn. Rept., 1863, p. 653; Proc. Cal. Acad. Sci., \'ol. Ill, 1864, p. 215. Cooper, 7th Ann. Rept. Cal. .St. Min , 1888, p. 231. Trvon, Man. Conch., Vol. XI, p. 371, PI. LXVII, fig. 54, 1889. Keep, West Coast Shells, p. 81, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, PI. XXII, fig. 3. Spire more acute than in other species of the genus; whorls six to seven, concave above, convex below; convex part has two or three rows of granular spiral ridges; concave surface orna- mented with a few fine granular spiral ridges; suture indistinct; base flat, marked by several smooth spiral ridges; aperture circular. Dimensions. — Alt. 18 mm.; lat. 15 mm.; defl. 46 degrees. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 331 Found in upper San Pedro series of San Pedro, Los Cerritos, and Crawfish George's. Found in the Pliocene at Packard's Hill, Santa Barbara; and in the Pleistocene at Spanish Bight, San Diego. Living. — -San Pedro to San Diego (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego, (Arnold). Pliocene. — Santa Barbara (Arnold). 384. Calliostoma tricolor Guhh. Calliostoma tricolor Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 186; Pal. Cal. , Vol. II, p. 17, PI. Ill, fig. 28, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Tryon, Man. Conch., Vol. XI, p. 370, PI. LXVII, fig. 52, 1889. Keep, West Coast Shells, p. 82, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, PI. XIX, fig. 8. Shell conical; spire elevated, subacute; whorls five to si.\, flat to concave, with prominent, rounded keel on anterior margin; surface ornamented with fine spiral lines; suture impressed, dis- tinct; base nearly flat, ornamented with fine spiral ridges and furrows; aperture subcircular; outer lip thin; columella slightly incrusted. Dimensions. — Alt. 11 mm.; lat. 11 mm.; defl. 66 degrees. Distinguishable by the prominent, smooth keel on the anterior part of whorls; and by the concavity and inconspicuous ornamentation of the upper part of the whorls. Rare in the Pliocene at Deadmau Island; in lower San Pedro series at San Pedro; and in upjier San Pedro series of Crawfish George's, San Pedro, and Los Cerritos. Found in the Pleistocene at Spanish Bight, San Diego. Living. — New Year Point to San Diego (Cooper): San Pedro (Arnold). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego (Arnold). Pliocene. — San Pedro (Arnold). Genus Norrisia Baijle. Shell thick, conoidal, orbicular, covered by an epidermis, smooth; widely umbilicated, umbili- cus surrounded by the callous extension of the columella; outer lip not thickened or sculptured within. Norrisia norrisii Sby. is a characteristic species. 385. Norrisia norrisii Sowerby. TrocMschics norrisii Sby., Tank. Catalogue, 1825. Cpr. , Brit. Assn. Rept., 1863, p. 652. = T. convexus Cpr. {^fide Gabb, Pal. Cal., Vol. II, p. 85, 1869). Tryon, Syst. and Struct. Conch., Vol. II, p. 315, PI. LXXXI, fig. 64, 1883. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 268. Keep, West Coast Shells, p. 86, fig. 72, 1892. Norrisia ?iorrisii Sby., Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 200. Shell of medium size, conoidal, orbicular, thick; spire only slightly elevated above body- whorl; whorls three or four, only very slightly convex, smooth except for lines of growth; suture 332 CALIFORNIA ACADEMY OF SCIENCES. only slightly appressed, distinct; aperture subtriangular; outer lip thin, slighdy bowed anteriorly; umbilicus large, deep, surrounded by callous extension of the columella. Dimensions. — Alt. 32 mm.; lat. 40 mm. Described from a living specimen. Found in upper San Pedro series at Deadman Island. Found also in the Pleistocene at Pacific Beach, San Diego. Living. — Santa Barbara to San Diego (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold). Genus Margarita Leach. Shell thin, globular-conical, umbilicated; whorls rounded, smooth; aperture rounded, pearly; lip sharp, smooth. Margarita helicina Fabr. is a characteristic species. 386. Margarita optabilis Carpenter, var. knechti, var. nov. Plate V, Fig. 14. Gibbida optabilis Cpr., Brit. Assn. Rept., 1863, p. 653. Shell small, conical, thin; turbinated apical whorls; whorls five; upper whorls rather angular, slightly tabulated above; body-whorl rounded, slightly angulated at base; two prominent spiral ridges, one at angle of whorl, the other near anterior margin; between these two ridges is a slightly concave surface sometimes ornamented with faint spiral ridges; oblique incremental lines quite prominent; suture impressed and distinct; base of body-whorl only slightly convex, and ornamented by five spiral ridges; umbilicus large, deep, effuse, smooth; aperture subrotund; inner lip incrusted and projecting slightly over umbilicus. Dime7isions . — Alt. 8.5 mm.; lat. 8 mm.; body-whorl 6.5 mm.; aperture 4.5 mm.; defl. 70 degrees. Some of the specimens retain their mottled coloration. The sculj^ture varies much in this variety, the number of spiral ridges varying; and the ridges sometimes being nodose and sometimes smooth. Sjiecimens pronounced variety of M. optahiVxM by Dr. Dall. Common in lower and rare in upper San Pedro series of San Pedro. The specimen figured is the type, which is from the lower San Pedro series at San Pedro, and is now in the United States National Museum. Fleistocene. — San Pedro (Arnold). 387. Margarita optabilis Carpenter, var. nodosa, var. nov. Plate V, Fig. 13. Gibbula optabilis Cpr., Brit. Assn. Rept., 1863, p. 653. Shell small, distinctly conical, thin; whorls five, flat, and ornamented by two prominent slightly nodose spiral ridges, each about one-fourth width of whorl from margin; between these two ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OP SAN PEDRO. 333 ribs, and also near the posterior margin of whorl, are less prominent ridges; incremental lines visible; body-whorl angular, with nodose ridge on angle; base of this whorl nearly flat, and ornamented with two prominent nodose spiral ridges and several lesser ones; umbilicus deep, but not very eflTuse; aperture ovate; inner lip slightly overlapping umbilicus; suture not impressed, indistinct. Dimetisiotis, — Alt. 6.5 mm.; lat. 6.5 mm.; body-whorl 5 mm.; aperture 3.5 mm.; defl. 75 degrees. This variety is distinguishable by its simple conical shape, flat whorls, and nodose ridges. It may grade into the turbinated, convex-whorled variety, M. knechti, although no mutations have been found in the large series at hand. This form was pronounced a variety of M. optabilis by Dr. Dall. Found in the lower San Pedro series of San Pedro and Deadman Island. The specimen figured is the type, which is from the lower San Pedro series at San Pedro, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). 388. Margarita parcipicta Carpenter, var. pedroana, var. nov. Plate V, Fig. 16. Gibbula parcipicta CpR., Brit. Assn. Rept., 1863, p. 653; Ann. & Mag. Nat. Hist., 3rd Ser., Vol. XIV, 1864, p. 427. Shell small, thin, globular, conical; spire elevated, subacute; whorls four, rounded, tabulated near posterior margin; four spiral ridges on upper whorls; suture deeply impressed and distinct; base of body-whorl rounded, and ornamented by fine spiral ridges; umbilicus deep and effuse; aperture subcircular. Dimensions. — Alt. 5.5 mm.; lat. 5.5 mm.; body-whorl 4.5 mm.; aperture 3 mm.; defl. 80 degrees. Specimens pronounced variety of M. parcipicta by Dr. Dall. Found in the lower San Pedro series at Deadman Island and San Pedro; and in the upper San Pedro series at Deadman Island, San Pedro, and Los Cerritos. The sjjecimen figured is the type, which is from the lower San Pedro series at San Pedro, and is now in the United States National Museum. Pleistocene. — San Pedro (Arnold). 389. Margarita pupilla Gould. Plate X, Fio. 15. Trocluts pjipilliis Gld , Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1850, p. 91; Wilkes' Expl. E.xped., Vol. XII, p. 186, fig. 208, 1852. Margarita pupilla Gld., = M. calostoma A. Ads. i^fide Cpr., Brit. Assn. Rept., 1S63, p. 653). =: M. salmonea CpR. {Jide Cooper, 7th Ann. Rept. Cal. St. Min. , 1888, p. 249). Trvon, Man. Conch., Vol. XI, p. 295, PI. XLIV, figs. 29-32, 1889. Keep, West Coast Shells, p. 78, fig. 63, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 202. Shell small, ovate-conic, rather solid; whorls five, convex, flattened slightly above, forming a narrow, tabulate band just below suture; body-whorl obtusely angulated; surface sculptured with 334 CALIFOENIA ACADEMY OF SCIENCES. small, flattened, subeqiial, equidistant, revolving ribs, five on the upper whorls; interspaces orna- mented by fine, oblique, incremental lines; base of body-whorl nearly flat, and ornamented with numerous fine, revolving lines, which become coarser near umbilicus; suture deeply impressed, dis- tinct; aperture circular; columella somewhat arcuate; umbilicus small, groove-like; outer lip sharp, nacreous layer on inner lip. Dimensions. — Alt. 5.8 mm.; lat. 8 mm.; defl. 67 degrees. Somewhat resembles Solariella peramabilis, but may be distingiiislied by smaller umbilicus; flatter, finer sculptured base; whorls less flattened above and finer sculp- tured, both spiral and transverse. Dr. Dall pronounced the Pliocene specimen a variety of M. 'pupilla. Found in Pliocene at Deadman Island; two specimens, one of which is figured, and is now in the collection of Delos Arnold. Found also in the Pleistocene at the bath-house, Santa Barbara. Living. — Alaska to Catalina Island, rare at latter place (Cooper). Pleistocene. — Santa Barbara (Cooper; Arnold). Pliocene. — San Pedro (Arnold). Genus Solariella S. Wood. Shell thin, globular-conical; generally with wide crenated umbilicus; whorls rounded, sculptured; aperture rounded; lip sharp, smooth. Solariella peramabilis Cpr. is a characteristic species. 390. Solariella cidaris A. Adams. Plate VII, Fig. 11. Margarita cidaris A. Ad., Cpr., Brit. Assn. Rept., 1863, p. 653. Cpr., Ann. Mag. Nat. Hist., 3rd Sen, Vol. XIV, 1864, p. 426; Vol. XV, 1865, p. 29. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 249 (young); ^= Solariella oxybasis Dall {fide Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1S94, p. 27). Turcicula cidaris (A. Ad.) Cpr., Tryon, Man. Conch., Vol. XI, p. 331, 1889. Solariella cidaris A. Ad., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 202, Pi. XXII, fig- 4- Shell conical; spire elevated, subacute; whorls six to seven; four upper whorls only slightly conve.x; lower whorls very convex; surface ornamented with spiral rows of nodes which grade into nodose ribs on the lower side of the body-whorl; suture deeply impressed; aperture circular; outer lip thin; inner lip and columella enameled, the incrustation completely obscuring the small umbilicus in most specimens. Dimensions. — Alt. 40 mm.; lat. 33 mm.; body-whorl 26.5 mm.; aperture 13 mm.; defl. 66 degrees. The specimen described and figured is an exceptionally large one, the average altitude being only 18 mm. Identification by Dr. Dall. Rare in the Pliocene; only about a dozen specimens found, and all of these from the Pliocene of Deadman Island. According to Dr. Cooper, San Marcial is on ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHT OF SAN PEDRO. 335 the peninsula of Lower California, and is in the Tertiary belt. This would corres^oond to the horizon of the formation at Deadman Island, where they are found only in the Pliocene. The specimen figured is from the Pliocene of Deadman Island, and is now in the collection of Delos Arnold. Living. — Neeah Bay to Catalina Island (dredged) (Cooper). Pleistocene. — San Marcial (Carpenter). Pliocene. — San Pedro (Arnold; Williamson). 391. Solariella peramabilis Carpenter. Plate VII, Fio. 2. Solariella peramabilis CpR., Brit. Assn. Rept., 1863, p. 653. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 265. Tryon, Man. Conch., Vol. XI, p. 312, PI. LXVII, figs. 59-61, 1889. Will- iamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 202. Shell small, conical; spire elevated, subacute; whorls five, conve.x, with narrow tabulate band just anterior to suture, and ornamentation of five or six spiral ribs crossed by fine lirulae; suture deeply impressed; aperture circular; umbilicus open, large, with three internal spiral lines. Dimensions. — Alt. 14.5 mm.; lat. 12 mm.; body-whorl 10.2 mm.; aperture 5 mm.; defl. 82 degrees. The specimen described was identified by Dr. Dall. Rare in the Pliocene; four specimens found in the Pliocene of Deadman Island. The specimen figured is from the Pliocene of Deadman Island, and is now in the collection of Delos Arnold. Living. — Catalina Island (30 fathoms) (Williamson). Pliocene. — San Pedro (Arnold). Family LXXXV. CYCLOSTREMATIDiE. Genus Vitrinella C. B. Adams. Shell minute, depressed turbiniform; widely umbilicated; aperture large, rounded. Vitrinella anomala d'Orb. is a characteristic species. 392. Vitrinella williamsoni Ball. Vitrinella ivilliamsoni Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 202, PL XXI, figs. 2 and 3. " Shell small, white, depressed, with two and a half whorls; spire flattened; suture appressed, with a shallow channel or excavation outside of the appressed margin of the whorl, outside of which the convexity of the whorl rises higher than the suture; base slightly more rounded than the upper side, with a wide and flaring umbilicus; periphery rounded; aperture rounded, oblique; surface pol- ished, finely striated here and there by the incremental lines, which are most prominent above. "Dimensions. — Maximum diameter of shell, 5.5 mm.; minimum diameter, 4.5 mm.; alti- tude, 1.25 mm." 336 CALIFORNIA. ACADEMY OF SCIENCES. Several specimens of this species were found in the lower San Pedro series of San Pedro. They were in a perfect state of preservation, and if they liad been found on the beach would, no doubt, have been called "dead shells." It is possible that some of the shells reported as "dead on beach" have been washed down from the fossil beds, and have been listed as living. Found in the upper San Pedro series of San Pedro, and the lower San Pedro series of Deadman Island; rare. Living. — Sau Pedro (Williamson). Pleistocene. — San Pedro (Arnold). Superfamily ZYGOBRANCHI A. Family LXXXVI. HALIOTIDiE. Genus Haliotis Linne. Shell ear-shaped, with a small flat spire; aperture very wide, iridescent; exterior striated, dull; outer angle perforated by a series of holes, those of the spire progressively closed. Haliotis gigantea Chemn. is a characteristic species. 393. Haliotis fulgens Philippi. Haliotis fulg ens Phil., Zeitschr. f Mai., p. 150, 1S45; Abbild. und Beschreib., p. 11, Pis. VII and VIII, fig. I, 1847. Cpr., Brit. Assn. Rept., 1863, p. 574. Tryon, Man. Conch., Vol. XII, p. 81, PL XII, figs. 61, 62, 1890. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 198. Haliotis splendens RvE., Icon. Conch., PI. Ill, fig. 9. Keep, West Coast Shells, p. 90, fig. 76, 1892. Weinkauff, Conch. Cab., p. 24, Pis. VII and VIII. Shell large, flat, oval; spire very slightly raised near margin of shell; surface spirally grooved, the grooves appearing as ridges on the interior; holes four to seven, elevated margins; interior highly colored; outer layer of shell brownish red. Dimensions. — Long. 112 mm.; lat. 88 mm.; depth 21 mm. Distinguished from H. rufescens and H. cracheroidii by grooved surface and colors of interior. This specimen, which was found in the conglomerate of the upper San Pedro series of Deadman Island, is probably the first authentic record of an Haliotis from the Pleistocene of California. It was a perfect specimen when found, but in remov- ing it from the matrix it was unfortunately broken into several fragments. A small but perfect specimen of this species was found in the Pleistocene (upper San Pedro series) at Spanish Bight, San Diego. Dr. Cooper has reported //. cracheroidii and H. ri/fescens from the Pleistocene of San Pedro, but upon examination of the fossils (?) upon which he based his rejwrt, which are now in the State Museum Collection at the University of California, they ARNOLD— THE PALEONTOLOGY AND STEATIGEAPHT OP SAN PEDRO. 337 were found to be recent shells from the kitchen-middens that overlie all of the San Pedro fossil deposits. The mistake of reporting kitchen-midden shells as " Pleisto- cene " and "Pliocene" has been made by a number of collectors, who have mis- taken these accumulations for fossil deposits. The two species of Haliotia above referred to, besides H. fulgens, are common in many of the kitchen-middens along the coast, and especially so in those around San Pedro. Living. — Monterey to Lower California (Carpenter). Pleistocene. — San Pedro; San Diego (Arnold). Family LXXXVII. FISSUEELLID^. Subfamily FISSURELLIDEIN^. Genus Lucapina Gray. Shell oval-oblong, conic, depressed, cancellated; summit subcentral, the oval opening sur- rounded by a callus; margin crenulated. Lucapina crenidata Sby. is a characteristic species. 394. Lucapina crenulata Sowerhy. Fissurella cremdata Sby., Tank. Catalogue, App., p. vi, 1825; Conch. 111., No. 19, figs. 31, 38, 1831. Z-i^fiT/J/wa trif?;/^/^/^ Sby., Cpr., Proc. Zool. Soc. , 1856, p. 223. Cpr., Brit. Assn. Rept., 1863, p. 651. Gabb, Pal. Cal. Vol. II, p. 85, 1869. Tryon, Struct, and Syst. Conch., Vol. II, p. 326, PI. LXXXIII, fig. 17, 1883. Tryon, Man. Conch., Vol. XII, PI. XLIV, figs. 95, 96, 1890. Keep, West Coast Shells, p. 95, fig. 79, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 198. Shell large, oval, conical, depressed; surface cancellated with numerous radiating ridges and concentric incremental lines; summit subcentral, the oval opening surrounded by a callus; margin crenulated. Dimensions. — Long, go mm.; lat. 57 mm.; alt. 20 mm. This species is distinguishable by its large size and rather faint sculpture. Rare in the upjier San Pedro series at Los Cerritos. Living. — San Pedro to San Diego (Carpenter; Williamson). Pleistocene. — San Pedro (Arnold). Subfamily EMARGINULINjE. Genus Fissuridea Siuainson. Shell oval, conical, depressed, with the ape.x in iront of the center, and perforated by oblong opening; surface radiated or cancellated; margin crenulated; callosity often truncate, sometimes aminated. Fissuridea incequalis Sby. is a characteristic species. ( 43 ) May 4, 1903. 338 CALIFOENIA ACADEMY OF SCIENCES. 395. Fissuridea aspera Eschscholtz. Fisstirella aspera EsCH., Zool. Atlas, Vol. V, p. 21, PI. XXIII, fig. 5, 1833. Glvphis aspera EsCH., Cpr., Proc. Zool. Soc, 1856, p. 223. Cpr., Brit. Assn. Rept., 1863, p. 651. Garb, Pal. Cal., Vol. II, p. 85, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 241. Keep, West Coast Shells, p. 96, fig-. 80, 1892. Fissuridea aspera EscH., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 197. Shell oblong, conical; anterior and posterior slopes only very slightly convex; apical hole anterior to center, nearly circular, the plane of its outer rim sloping considerably forward; numerous prominent, straight, rough ribs radiate from the apical hole and produce a corrugated margin for the shell; inner side of rim corrugated and slightly effuse; inner surface smooth. Dimensions.— X^O'^i^. 60 mm.; lat. 42 mm.; alt. 23 mm. Easily distingiii.sluible by its Isirge size and prominent, rough, radiating ridges and alternating color bands. Has fewer and rougher ribs than F. marina, and a more elliptical apical hole. Not uncommon in the lower San Pedro series at Deadman Island and San Pedro; common in the upper San Pedro series at Crawfish George's, and rare in the same formation at Los Cerritos, Deadman Island, and San Pedro. JAving. — Sitka to San Pedro (Cooper). Pleistocene. — Santa Barbara to San Pedro (Cooper): San Pedro (Arnold). 396. Fissuridea inaequalis Sowerby. Fissurel/a incequalis Sby., Proc. Zool. Soc, 1834, p. 126; Conch. Ill , fig. 45. Reeve, Conch. Icon., fig. 50. Glyphis ineequalis Sv.Y., Cpr., Brit. Assn. Rept., 1856, p. 184, PI. VII, figs. \a-^7i. Tryon, Man. Conch., Vol. XII, p. 215, PI. XXXIV, figs. 63, 64, 1S90. Fissurella pica Sby., Proc. Zool. Soc, 1834, p. 126; Conch. 111., Vol. II, figs. 32, 33. Reeve, Conch. Icon., fig. 49. Fissurella incequalis va.r. pica vSbv., Cpr., Brit. Assn. Rept., 1856, p. 184. Tryon, Man. Conch., Vol. XII, p. 215, PI. XXXIV, fig. 64, 1890. Shell oblong, conical, much depressed; anterior and posterior surfaces conve.x; lateral view of margin a line conve,\ upward (as if shell had been on a convex surface); radiating ridges numer- ous and fine; concentric ridges numerous and nearly as prominent as the radiating ridges; the two systems of lines giving the surface a decidedly cancellate appearance; apical hole slightly oblong, anterior to center; inner surface smooth; inner surface of margin finely corrugated; color white. Dimensions. — Long. 22.5 mm.; lat. 12 mm.; alt. 6 mm. Distinguishable from other members of tliis genus occurring in this formation by its small size and the convex appearance of the sloping sides. The specimen described was identified by Dr. Dall. Six specimens in the upper San Pedro series of San Pedro; also found in the same horizon at Los Cerritos, Deadman Island, and Long Beach. Living. — Guacomayo; Galajiagos Islands (Carpenter). Pleistocene. — San Pedro (Arnold). ARNOLD — THE PALEONTOLOGY AND STEATIGEAPHY OF SAN PEDRO. 339 397. Fissuridea murina {Carpenter) Dall. G typhis dcnsiclalhraia var. imiritta Cpr., mss. Fissurida: murma (Cpr.) Dall, Proc. U. S. Nat. Mus., Vol. VIII, 1885, p. 543; Vol. XV, 1892, p. 197. Glyphis deyisiclathrata RvE., Tryon, Man. Conch., Vol. XII, p. 215, PI. XXXIX, fig. 81, 1890 (pars). Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 27. Shell resembles F. aspcra in general outline; apical hole nearly central, circular; radiating ridge.s numerous and smooth, e.xcept for line incremental lines; inner margin of shell quite evenly crenulated; color white. Dimensions. — Long. 46 mm.; lat. 30 mm.; alt. 16 mm. Distinguishable from F. aspera by lack of coloration, finer and more numer- ous ribs, more central ;ui(l more nearly roniul apical hole. Smaller than tlie latter. Dr. Dall says that this is the same species which Californian conchologists have been calling Glijphis densiclnthrafa,hut that it is not the same as Reeve's G. dent^idnthratd. Four specimens in the upper San Pedro series of San Pedro; found in tlie same horizon at Deadman Island, Los Cerritos, and Crawfish George's; and in the lower San Pedro series at Deadman Island. Living. — San Pedro; Catalina (Williamson): Santa Barbara (Cooper). Pleistocene. — San Pedro (Arnold) : San Joaquin Bay, Orange County (Bowers). Genus Clypidella Sivainson. Shell oval, rugose, slightly elevated, truncated at the anterior extremity; perforation large, subcentral, or somewhat anterior, Clypidella pustnlata Lam. is a characteristic species. 398. Clypidella bimaculata Bull. Clypidella (f) bimaculala Dall, mss., in CooPER, Geol. Cat. W. C. Shells, No. 470, 1866. Fissurellidiea bimaculata Dall, Am. Jour. Conch., Vol. VII, 1872, p. 132, PI. XV, fig. VII. Keep, West Coast Shells, p. 97, fig. 82, 1892. Clypidella bimaculata Dall, Gabb, Pal. Cal., Vol. II, pp. 86, 124, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1S88, p. 235. Megatebeniius bimaculatus Dall, Tryon, Man. Conch., Vol. Xll, p. 183, PI. XLIV, fig. 94, 1890. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 198. Shell resembles C. callomarginaia. Aperture and apical hole elliptical, the latter being central; wide, thickened ridge on inner side of rim and on inner side of apical hole. Smaller than C. callomarginata. Specimens identified by Dr. Dall. Not uncommon in the lower San Pedro series of Deadman Island and San Pedro; rare in the upper San Pedro series of Los Cerritos and San Pedro. Living. — Farallon Islands to Santa Barbara Islands (Cooper). Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold). 340 CALIFORNIA ACADEMY OF SCIENCES. 399. Clypidella callomarginata Carpenter. "Cfyptde//a callomarginata Cpr., Brit. Assn. Rept., 1866." Gabb, Pal. Cal., Vol. II, pp. 86, 124, 1869. Dall, Am. Jour. Conch., Vol. VII, 1872, p, 133, PI. XV, fig, 8. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 235. Tryon, Man. Conch., Vol. XII, p. 197, PI. XLIV, figs. 3, 4, 5; PI- LXI, figs. 1-5, 1890. Fissurellidcea callomarginata CpR., Keep, West Coast Shells, p. 97, 1892. Lucapinella callomarginata Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 198. Shell elongate-ovate, conical, depressed; apical hole elongate-ovate, large, not central; surface sculptured by alternating large and small radiating ridges, and prominent, concentric raised lines; aperture elongate-ovate; margin crenulated, thickened. Dim,ensions. — Long. 22 mm.; lat. 12 mm.; alt. 4.5 mm. The specimen described was identified by Dr. Dall. Rare in the lower San Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series of Crawfish George's, Los Cerritos, and San Pedro. Living. — Lobitos to San Diego (Cooper). Pleistocene. — San Pedro to San Diego (Cooper): San Pedro (Arnold). Genus Fissurella Bruguiere. Shell oval, conical, depressed, with the ape.x in front of the center, and perforated; surface radiated or cancellated. fissurella picta Gmel. is a characteristic species. 400. Fissurella volcano Reeve. Fissurella volcano RvE., Icon. Conch., PL IV, fig. 2, 1849. Sby., Thes. Conch., Vol. Ill, p. 192, fig. 87. Cpr., Brit. Assn. Rept., 1863, p. 651. Gabb, Pal. Cal., Vol. II, p. 86, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 240. Tryon, Man. Conch., Vol. XII, p. 156, PI. LXII, figs. 16-1S, 1890. Keep, West Coast Shells, p. 96, fig. 81, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 197. Shell oblong, conical, apical hole oblong, slightly anterior to center; numerous small radi- ating ribs run down to the margin; margin smooth; alternating red and dark colored stripes radiate from the apical hole; sloping surface straight. Dimetisions. — Long. 27 mm.; lat. 19 mm.; alt. 10 mm. Distinguishable by the coloration, which is apparent in all the Pleistocene specimens that have been examined. Much smaller than F. as'pera Esch., which is the only Pleistocene limpet it resembles. Rather common in the lower San Pedro series at Deadman Island and San Pedro; and in the upj^er San Pedro series at Deadman Island, Los Cerritos, Crawfish George's, and San Pedro. Found in the Pleistocene at Pacific Beach, San Diego. Living. — Santa Cruz to San Diego (Cooper). Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; San Diego (Arnold). ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 341 Genus Puncturella Loive. Shell conical, elevated, with the apex recurved; perforation in front of the apex, with a raised border (septum) internally; surface cancellated. Puncturella noachina Linn, is a characteristic species. 401. Puncturella cucullata Gould. Rimula cucullata Gld., Proc. Bost. Soc. Nat. Hist., Vol. II, 1846, p. 159; Wilkes' Expl. Exped., Vol. XII, p. 268, fig. 475, 1852. Puncturella cucullata Gld., Cpr. , Brit. Assn. Rept., 1863, p. 651. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 261. Tryon, Man. Conch., Vol. XII, p. 232, PI. XLII, figs. 72-75; PI. LXIII, figs. 38, 39, 1890. Shell shaped like an oblique cone, with an elevated acute apex posterior to the center and curving forward like a curved beak; sixteen to eighteen prominent radiating ribs with three to five less prominent ribs between each of the larger; ribs muricated by fine incremental lines; fissure narrow and narrowing upwards; aperture ovate; inner edge crenulated, furrows following the external ridges only for short distance from ribs. Dimensions. — Long. 22 mm.; lat. 15.5 mm.; alt. 13.5 mm. The specimen described was identified by Dr. Dall. Rare in lower San Pedro series of San Pedro; four specimens; also found in Pliocene of Deadraan Island; and upper San Pedro series at San Pedro. Found in the Pliocene at Packard's Hill, Santa Barbara. Living. — Straits of Fuca to Monterey (Cooper). Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). Pliocene. — Packard's Hill, Santa Barbara (Arnold). 402. Puncturella galeata Gould. Rimula galeata Old., Proc. Bost. U. S. Nat. Hist., Vol. II, 1846, p. 159; Wilkes' Expl. Exped., Vol. XII, p. 369, fig. 476, 1852. Puncturella galeata Gld., Cpr., Brit. Assn. Rept., 1863, p. 651. Tryon, Man. Conch., Vol. XII, p. 230, PL XLII, figs. 62-65, 1890. Shell erect, conical; apex central, elevated, acute, with the point hooked forward; numerous, nearly equal, sharp raised lines radiate from the apex; incremental lines fine and numerous; fissure narrow and small; in front of sulcus, near the summit, is a transverse rib having between it and the formix on each side a little triangular pit. Dimeyisions. — Long. 8.1 mm.; lat. 5.5 mm.; alt. 6 mm. The sjjecimen described was identified by Dr. Dall. One specimen in lower San Pedro series of San Pedro; also found in Pliocene of Deadraan Island. Living. — Puget Sound district (Carpenter). Pleistocene. — San Pedro (Arnold). 342 CALIFORNIA ACADEMY OF SCIENCES. Subclass ISOPLEURA. Order POLYPLACOPHORA. Superfamily EOCHITONIA. Family LXXXVIII. CHITONID.E. Genus Ischnochiton Gray. Shell thin; laminffi of insertion regular, acute, neither pectinate nor serrate; eaves large; sinus usually smooth; girdle squamose, the squama; generally striate. Ischnochiton longicymoa Blainv. is a characteristic species. 403. Ischnochiton regularis Carpenter. Chiton regularis Cpr., Proc. Zool. Soc, 1855, p. 232. hchnochiton regularis Cpr., Keep, West Coast Shells, p. 107, fig. 93, 1892. Tryon, Man. Conch., Vol. XJV, p. 142, PI. XVIII, figs. 41, 46, 1892. Shell depressed, elongate-oval, width half of length; valves not sharply arched; lateral areas ornamented with concentric, slightly granular ridges and fine radiating lines; central area with inconspicuous fine irregular lines; apex smooth; mucro longitudinally ridged with irregular raised lines. Description partly from living shell. The only fossil rejjresentative of this sjjecies so far reported is a perfect central valve found in the upper San Pedro series of San Peih-o in 1894 by Dr. G. H. Ashley. Living. — Monterey (Carpenter): West Coast (Keep). Pleistocene. — San Pedro (Ashley). Genus Gryptochiton Mldd. d- Gray. Shell large; valve entirely immersed in the girdle, which is minutely fasciculately pilose. Type, Cryptochiton stelleri Midd. 404. Gryptochiton stelleri Mkidendorff. Chiton stelleri Miuu., Bull. Acad. St. Peters., Vol. VI, 1S46, p. 116. Chiton (yCryptochitori) stelleri M\t>d., Mai. Ross., Pt. i, p. 93, PI. I, figs, i, 2, 1847. Chiton amiciilatus S^\., Thes. Conch., Ill, Chitons, fig. 80. Chiton sitkensis RvE., Icon. Conch., PI. X, sp. 55. CryptochiloH stelleri Midd., Cpr., Brit. Assn. Rept. , 1863, p. 648. Gabb, Pal. Cal., Vol. 11, p. 87, 1869. Tryon, Struct, and Syst. Conch., Vol. II, p 346, PI. LXXXV, fig. 83, 1883. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 237. Keep, West Coast Shells, p. in, fig- 99, 1892. Tryon, Man. Conch., Vol. XV, p. 148, PI. VII, figs. 7-13; PL VI, fig. 6, 1893. Chiton calif orniais Prescott, Am. Jour. Sci., 2nd Ser., Vol. XXXVIII, 1864, p. 185. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 343 One valve was found in the lower San Pedro series of Deadman Island, and two in the Pliocene of the same locality. One is probably an end valve and is distinguishable by its strong convexity, thickness, and smooth surface. It has a .small, acute notch on each side near the end. Dimensions. — Long. 20 mm.; lat. 30 mm.; alt. 13 mm. Living. — Straits of Fuca to Monterey; Kamtschatka (Cooper): Hakodate, Japan (?) (Carpenter). Pleistocene. — San Diego (Cooper): San Pedro (Arnold). Pliocene. — Deadman Island, San Pedro (Arnold). Superfamily OPSICHITONIA. Family LXXXIX. MOPALIID^. Genus Mopalia (rraij. Shell regular; laminae lengthened; anterior valve with six or more slits, the others with a single slit; last valve sinulate behind; sinus narrow, mucro median, depressed; sutures indented; girdle wide, bristly, sometimes fissured behind, sometimes projecting anteriorly. Mopalia hlainvillei Brod. is a characteristic species. 405. Mopalia ciliata Soiverby. Chiton muscosus Gld., Proc. Best. Soc. Nat. Hist., Vol. II, 1846, p. 145; Wilkes' Expl. Exped., Vol. XII, p. 313, fig. 436, 1852. Mopalia muscosa Gld., Cpr. , Brit. Assn. Rept., 1863, p. 648. Mopalia ciliata Sby., Keep, West Coast Shells, p. no, fig. 98, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 196. Shell depressed, rather broad, oval; obliquely ridged along the back; sculpture prominent and covering whole of surface; side areas sculptured with granulated, radiating ridges; central area ornamented with longitudinal, granulated, raised lines; mucro median depressed, ornamented with sharp, oblique lines which meet on middle and form an acute angle open anteriorly; anterior valve large, semicircular, with ten granulated, elevated, radiating lines, and interspaces granulated as in lateral areas. Dimensions. — Long. 40 mm.; lat. ig mm.; depth 6 mm. Description from living specimen. The only specimen of this species ever reported in the fo.ssii state was found in the upper San Pedro series of San Pedro. It is a perfect anterior valve, 10 millimeters wide and 5.2 millimeters long. Living. — Vancouver to Monterey (Carpenter): San Pedro (Williamson). Pleistocene. — San Pedro (Arnold). 344 CALIFOKNIA ACADEMY OF SCIENCES. ARTHROPODA. Class CRUSTACEA/ Subclass EUCRUSTACEA. Superorcler CIRRIPEDIA. Order THORACICA. Family XC. BALANID.E. Genus Balanus Lister. Shell low, conical or cylindrical, composed of six pieces. Opercular plates subtriangular; base membranous or calcareous. 406. Balanus concavus Bronn. Balanus co7icavus Bronn, Italiens Tertiar-Gebilde (1S31) et Lethaea Geognostica, b, II, 3, 1155 (1838), Tab. XXXVI, fig. 12; = B. cylindraceus var. concavus Lam.; = Lepas tintinnabuhmi Brocchi, {^fide Darwin, Monog. Cerripedia, II, p. 235, PL IV, fig. 4a-412b. Preliminary Descriptions of New Species of Mollusks from the Northwest Coast of America. Proc. Cal. Acad. ScL, Vol. IV, 1872, pp. 270-271 and 302-303. 1873a. Catalogue of the Recent Species of the Class Brachiopoda. Proc. Acad. Nat. Sci. Phila., 1873, pp. 177-204. 1873^. Descriptions of New Species of Mollusca from the Coast of Alaska, with Notes on Some Rare Forms. Proc. Cal. Acad. Sci., Vol. V, 1873, pp. 57-62. 1874a. Notes on Tertiary Fossils from the California Coast, with a List of the Species Obtained from a Well at San Diego, California. Proc. Cal. Acad. Sci., Vol. V, 1874, pp. 296-299. 1874^. Catalogue of Shells from Behring Strait. Proc. Cal. Acad. Sci., Vol. V, 1874, pp. 246-253. 1877a. Report on the Brachiopoda of Alaska and the Adjacent Shores of Northwest America. Proc. Acad. Nat. Sci. Pliila., 1877, pp. 155-170. Scientijic Results, Art. Ill, 1877, pp. 45-62. 1877^. Preliminary Descriptions of New Species of Mollusks from the Northwest Coast of America. Proc. Cal. Acad. Sci., Vol. VII, 1877, p. 6. 1877c. On the Californian Species of Fusus. Proc. Cal. Acad. Sci., Vol. VII, 1877, p. 5. 1878a. Descriptions of New Shells from California. Proc. U. S. Nat. Mus., Vol. I, 1878, pp. 46-47. 1878(5. Distribution of Californian Tertiary Fossils. Proc. U. S. Nat. Mus., Vol. I, 1878, pp. 26-30. 1878^. Report on the Limpets and Chitons of the Alaskan and Arctic Regions, etc. Proc. U. S. Nat. Mus., Vol. I, 1878, pp. 281-344. Scientijic Results, Art. IV, 1879, pp. 63-126. i878(^. Post-Pliocene Fossils in the Coast Range of California. Proc. U. S. Nat. Mus., Vol. I, 1878, p. 3. 1878^. Fossil Mollusks from Later Tertiaries of CaHfornia. Proc. U. S. Nat. Mus., Vol. I, 1878, pp. 10-16. 352 CALIFORNIA ACADEMY OF SCIENCES. 1881. On the Genera of Chitons. Proc. U. S. Nat. Mus., Vol. IV, iSSi, pp. 279-291. 1S83. List of Papers by W. H. Dall, from 1866 to 1882. 3 vols. Washington, 1883. Kepriuts of principal papers by this writer. 1884a. Report on the Mollusca of the Commander Islands, Behring Sea, Collected by Leonhard Stejneger in 1882 and 1883. Proc. U. S. Nat. Mus., Vol. VII, 1884, PP- 340-349. P'- II- 18843. New or Specially Interesting Shells of Point Barrow Expedition. Proc. U. S. Nat. Mus., Vol. VII, 1S84, pp. 523-526, PI, II. 18861a;. Contributions to the Natural History of the Commander Islands. No. 6, Report on Behring Island Mollusca, Collected by Mr. Nicholas Grebnitzki. Proc. U. S. Nat. Mus., Vol. IX, 1886, pp. 209-219. 1 886(5. Supplementary Notes on Some Species of Mollusks of the Behring Sea and Vicinity. Proc. U. S. Nat. Mus., Vol. IX, i886, pp. 297-309, Pis. III-IV. 1889a. Catalogue of Shell-bearing Marine Mollusks, etc. , of Southeastern Coast of the United States. Bull. U. S. Nat. Mus., No. 37, 1889. iSSgi^. Preliminary Report on the Collection of Mollusca and Brachiopoda obtained in 1887-88 by the U. S. Fish Commission Steamer "Albatross." Proc. U. S. Nat. Mus., Vol. XII, 1889, pp. 219-362, Pis. V-XIV. 1890. Contributions to the Tertiary Fauna of Florida. Part I. Pulmonate, Opistho- branchiate and Orthodont Gastropods. Trans. Wagner Free hist. Set., Vol. Ill, Part I, 1890. 1 89 1. On Some New or Interesting West American Shells Obtained from the Dredgings of the U. S. Fish Commission Steamer "Albatross," in 1888, and from Other Sources. Proc. U. S. Nat. Mus., Vol. XIV, 1891, pp. 173- 191, Pis. V-VII. 1892^. and Harris, G. D. Correlation Papers. Neocene. Bull. U. S. Geol. Sur., No. 84, 1892. i892(^. Notes on Geology at La Jolla, San Diego, Cal. Nautilus, Vol. VI, No. 4, Aug., 1892, p. 88. 1892c. Contributions to the Tertiary Fauna of Florida. Part 2. Streptodont and Other Gastropods, Concluded. Trans. Wagner Free Inst. Sci., Vol. Ill, Part 2, 1882. 1894a. On the Species of Mactra from California. Nautilus, Vol. VII, No. 12, April, 1894, pp. 136-138, PI. V. 1894/J. Synopsis of the Mactridse of North America. Nautilus, Vol. VIII, No. 3, July, 1894, pp. 25-28; No. 4, Aug., 1894, pp. 39-43. i894(r. Report on Mollusks and Brachiopoda Dredged in Deep Water Chiefly Near the Hawaiian Islands, with Illustrations of Hitherto Unfigured Species from Northwest America. Proc. U. S. Nat. Mus., Vol. XVII, 1894, PP- 675-733, Pis. XXIII-XXXII. 1895a. Contributions to the Tertiary Fauna of Florida. Part. 3. A New Classification of the Pelecypoda. Tratts. Wagner Free Inst. Sci., Vol. Ill, Part 3, 1895. i895<5. Diagnoses of New Species of Mollusks from the West Coast of America. Proc. U. S. Nat. Mus., Vol. XVIII, 1895, pp. 7-20. 1896. New Sjiecies of Leda from the Pacific Coast. Nautilus, Vol. X, No. i, May, 1896, pp. 1-2. 1897a. Notice of Some New and Interesting Shells from British Columbia and the Adja- cent Region. Bidl. Nat. Hist. Soc. Brit. Columbia, Vol. II, 1897, pp. 1-18, Pis. I, II. AKNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDKO. 353 i897i5. New West American Shells. Nautihis, Vol. XI, No. 8, Dec, 1897, pp. 85-86. 1898a. —On a New Species of Fusus from California. Nautilus, Vol. XII, No. i, May, 1898, pp. 4-5. 1898(5. A Table of North American Tertiary Horizons, Correlated with One Another and with Those of Western Europe, with Annotations. i8th Ann. Kept. U.S. Geol. Sur., Part II, 1898, pp. 323-348. 1898^. Synopsis of the Recent and Tertiary Psammobidae of North America. Proc. Acad. Nat. Sci. Phila., 1898, pp. 57-62. 1898a?. Contributions to the Tertiary Fauna of Florida. Part. 4. Pelecypoda: I, Prio- nodesmacea; II, Teleodesmacea. Trans. Wag^ier Free Inst. Sci., Vol. Ill, Part 4, 1898. 1898^. Synopsis of the Recent and Tertiary Leptonacea of North America and the West Indies. Proc. U. S Nat. Mus., Vol. XXI, 1898, pp. 873-897. 1899. Synopsis of the Solenidae of North America and the Antilles. Proc. U. S. Nat. Mus., Vol. XXII, 1899, pp. 107- 1 12. 1900a. • — Contributions to the Tertiary Fauna of Florida. Part 5. Pelecypoda, Concluded. Travis. Wagner Free Inst. Sci., Vol. VI, Part 5, 1900. 1900(5. Synopsis of the Family Tellinidae and of the North American Species. Proc. U. S. Nat. Mus., Vol. XXIII, 1900, pp. 285-326, Pis. II-IV. 1901. — - — • — Illustrations and Descriptions of New, Unfigured, or Imperfectly Known Shells, Chiefly American, in the U. S. National Museum. Proc. U. S. Nat. Mus., Vol. XXIV, 1901, pp. 499-566, Pis. XXVII-XL. 1854. Darwin, Charles. A Monograph on the Subclass Cerripedia, with Figures of All the Species. Part II, pp. viii, 684, Pis. XXX. London, 1854. Printed for the Ray Society. 1839. Deshayes, G. p. New Species of Shells from West Coast of North America. Revue Zool., 1839. 1840. Magazine de Zoologie, 1840, Pis. XIV-XCVIII. Coutaius illustrations of new shells, unci also six previously clescribe(J by Conrad from the West Coast of North America. 1853-54. Catalogue of the Conchifera in the British Museum, Vol. I, 1853; Vol. II, 1854. 1789. Dixon, George. A Voyage Around the World. London, 1789. Appendix, P- 355. fig- 2. 1874. D'Orbigny, Alcide. Voyage dans I'Amerique Meridionale, 1826- 1833. Mollusca: 4to; 86 colored plates. Paris, 1874. Also published as a catalogue of the species in the British Museum, by Dr. J. E. Gray, 1854. 1832. Duclose, M. Synopsis of Purpura, giving New Species, etc. Ajui. Sci. Nat., Vol. XXIV, 1832, p. 103, with plates. Also figured in Mag. deZool., 1833. 1858-71. DuNKER, WiLHELM. Novitates Conchological. Series II. 4to, 48 plates. Cassel, 1858-1871. On marine shells only. 1874-83. Monographs on Buccinum, etc. Zeits. f. Mai., 1874- 1883. Also articles in Chemn. Conch. Gab., Ed. 2, on Planorbis, etc. 1900. Eastman, Charles R. Text-book of Paleontology, by Karl A. von Zittel. Trans- lated and edited by C. R. Eastman. Vol. I, pp. 706, 1476 woodcuts. Macmillan and Co., New York, 1900. ( 45 ) May 29, 190a. 354 CALIFORNIA ACADEMY OF SCIENCES. 1829. EscHSCHOLTz, J. F. Zoological Atlas. i Vol., 410; 24 plates, 5 of Mollusca. Berlin, 1829. Completed by Dr. M. H. Kathke, in 1833. 1893. Fairbanks, H. W. Geology of San Diego County; also of Portions of Orange and San Bernardino Counties, nth Ann. Repi. Cal. St. Mi?!., 1893, pp. 76-120. 1896. — The Geology of Point Sal. Bull. Dept. Geol. Univ. Cal., Vol. II, 1896, No. i, pp. 1-92, Pis. I-II. 1887. Fischer, Paul. Manuel de Conchyliologie et de Paleontologie Conchyliologique, etc., pp. xxiv -\- 1369, 23 plates and 1138 text figures. Paris, 1887. 1850. Forbes, Edward. West Coast Shells, Chiefly from Lower California, Collected by Captains Kellet and Wood, R. N., on a Surveying Voyage in Ships "Herald" and "Pandora." Proc. Zool. Soc, 1850, pp. 271-274. Marine Shells. 1855. and Hanley, S. History of British Mollusca and Their Shells. 4 Vols., 8vo, 202 plates. London, 1855. 1861. Gabb, William M. Fossils from California. Proc. Acad. Nat. Sci. Phila., 1861, p. 368. 1865. New Marine Shells from the Coast of California. Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 183, et seq. 1864-69. Geological Survey of California, J. D. Whitney, State Geologist. Paleontology, Vol. I, 1864; Vol. II, 1869, with 33 plates. Philadelphia, 1864-1869. 1788. Gmelin, J. F. Systema Naturae. Leipzig, 1788. 1846-51. Gould, Augustus A. Shells Collected by the U. S, Exploring Expedition under Captain Wilkes, U. S. N. Proc. Post. Soc. Nat. Hist., Vol. II, 1846, p. 142; Vol. Ill, 1849-50, p. 83; Vol. IV, 185 1, p. 27. 1 85 1. Shells from the Gulf of California and the Pacific Coast. Proc. Post. Soc. Nat. Hist., Vol. IV, 1 85 1, p. 87, with plates. 1853. Descriptions of Shells from the Gulf of California and the Pacific Coasts of Mexico and California. Post. four. Nat. Hist., Vol. VI, p. 374, 1853. Separates called Mexican and California Shells. 1852. Mollusca and Shells of the U. S. Exploring Expedition, etc. Report of the Ex- ploring Expedition laider Command of Captain Charles Wilkes, Vol. XII, text. Boston, 1852; plates, 1856. 1862. Otia Conchologica. Boston, 1862. Contains reprinted and corrected descriptions of nearlj' all of the species named by Dr. Gould, from 1839 to 186-2. 1824. Gray, John Edward. Monograph of the Cypraeidae. Zool. Jour., Vol. I, 1824, p. 71. 1826. Annals of Philosophy, Vol. XII, 1826, p. 103. 1827. Zoological Journal, Vol. Ill, 1827. 1839. The Zoology of the Voyage of the Ship Blossom, Captain Beechy, pp. 1 17-138, plates. London, 1839. 1847-49. On West Coast Chitonida-. Proc. Zool. Soc, 1847, p. 66. 1840-44. Haldeman, S. S. Monograph of the Limniades and Other Fresh Water Univalve Shells of North America. Philadelphia, 1840-1844. 1842-56. Hanley. Sylvanus. An Illustrative and Descriptive Catalogue of Recent Bivalve Shells, with 960 figures, by Wood and Sowerby. London. 1842-1856. Forming an Appendix to Wood's Index Testaceologicus, Ed. 3, 1856. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 355 1855. Ipsa Linnaei Conchylia. Royal 8vo, 6 colored plates. London, 1855. 1892. Harris, G. D. and Dall, W. H. Correlation Papers. Neocene. Bull. U. S. Geol. Sur., No. 84, 1892. 1902. Hershey, Oscar H. The Quarternary of Southern California. Bull. Dept. Geol., Univ. Cat., Vol. Ill, No. I, 1902, pp. 1-30, PI. I. 1842-44. Hinds, Richard B. On New Shells from California. A7in. Mag. Nat. Hist., Vol. X, 1842, p. 8r, PI. LXI; Vol. XI, 1843, p. 255; Vol. XII, 1843, p. 479; Vol. XIII, 1844, pp. 136 and 468; Vol. XIV, 1S44, pp. 8 and 63. Also, Proc. Zool. Soc, 1843-44. 1844. Zoology of the Voyage of H. M. S. "Sulphur," under Captain Sir Edward Belcher, 1836-1842. (Vol. II, MoUusca.) 21 plates. London, 1844. 1900. Holmes, Samuel J. Synopsis of California Stalk-Eyed Crustacea. Occasional Papers Cal. Acad. Set., Vol. VII, 1900. 1835. Jay, f. C. a Catalogue of Recent Shells in his Cabinet, with References and Synonyms. New York, 1835; 2nd Ed., 1836; 3rd Ed., 1839; 4th Ed., 1850. 1856. — List of Shells. Expedition to Japan under Commodore M. C. Perry, in 1852 to 1854. Vol. II, p. 289, 1856. 1862-69. Jeffreys, J. G. British Conchology. 5 vols., 8vo, 147 plates. London, 1862-1869. 1881. Keep.Josiah. Common Sea Shells of California. 64 pp., 95 figures. San Francisco, 188 1. 1892. West Coast Shells. 230 pp., 182 figures. San Francisco, 1892. 1834-79. Kiener, L. C. 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The Californian Trivia and Some Points in Its Distribution. Afii. Nal., Vol. VI, December, 1872, pp. 732-734, with figures. i873«. Descriptions of a New Genus and Two New Species of Nudibranchiate MoUusks from the Coast of California. Proc. Cal. Acad. Sci., Vol. V, 1873, pp. 77-78, with figures. i873<5. Descriptions of New Marine Mollusks from the West Coast of North America. Proc. Cal. Acad. Sci., Vol. V, 1873, pp. 78-82, with plate. 1873^. On Xylophagous Marine Animals. California Horticulturisi , etc.. May, 1873, with figures. 1873a'. Remarks on the Nudibranchiate or Naked-gilled Mollusks. California Horticul- turist, July, 1873. i873(!'. Aboriginal Shell-money. Proc. Cal. Acad. Sci., Vol. V, 1873, pp. 1 13-120, with plate. 1873/. Shells Collected at San Juanico, Lower California, by William M. Gabb. Proc. Cal. Acad. Sci., Vol. V, 1873, pp. 131-132. 1873^. Shells Collected at Loreto, Lower California, by W. M. Gabb in February, 1867. Proc. Cal. Acad. Sci., Vol. V, 1873, p. 132. 1873A. Aboriginal Shell-money. Overlatid Mojilhly, San Francisco, Sept., 1873, with figures. Also in Globus, Braunschweig, Germany, of about same date; without credit. i875«, 77. On the Vitality of Certain Land Mollusks. Proc. Cal. Acad. Sci., Vol. VI, 1875, pp. 185-187, with plate. Am. Nat., Vol. XI, Feb., 1877, pp. 100-102. i875iJ. Description of New Fossil Shells from the Tertiary of California. Proc. Acad. Nat. Sci. Phila., 1875, pp. 463-464, with plates. \%1-]a. Aboriginal Shell-money. AtJi. Nat., Vol. XI, June, 1877, pp. 344-350, with figures and plate. 1877(5. Aboriginal Shell Ornaments, and Mr. F. A. Barber's paper thereon. Am. Nat., Vol. XI, Aug., 1877, PP- 473-474- 1878. Description of a New Species of Dolabella from the Gulf of California, with Remarks on Other Rare or Little Known Species from the Same Region. Proc. Acad. Nat. Sci. Phila., 1878, pp. 395-401, PI. VII. 1879a. Remarks on Fossil Shells from the Colorado Desert. Afn. Nat., Vol. XIII, 1879, pp. 141-154; several figures. Read before the California Academy of Sciences. 1879^. Description of a New Species or Variety of Land Snail from California (Helix cir- cumcarinata). An7i. N. Y. Acad. Sci., Vol. I, 1879, pp. 316-317, 3 figures. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 359 i88ra. Observations on Planorbis; are the Shells of Planorbis Dextral or Sinistral ? On Certain Aspects of Variation in American Planorbes. Proc. Acad. Nat. Set. Phila., 1 88 1, pp. 92-110, with 27 figures. i88ii5. Mya arenaria in San Francisco Bay. Am. Nat., Vol. XV, May, 1881, pp. 362-366. iSSif. On Helix aspersa in California, and the Geographical Distribution of Certain West American Land Snails, etc. Ann. N. Y. Acad. Set., Vol. II, i88r, pp. 129-139. 1882a. Verification of the Habitat of Conrad's Mytilus bifurcatus. Proc. Acad. Nat. Set. Phila., 1882, pp. 241-242. 1882^. On the History and Distribution of the Fresh-Water Mussels and the Identity of Certain Alleged Species. Proc. Cal. Acad. Set., November 20, 1882, 21 pages and figures. 1883a. On the Shells of the Colorado Desert and the Region Farther East; Part I. The Physas of Indio; Part II. Anodonta californiensis in a New Locality. Am. Nat., Vol. XVII, Part 2, October, 1883, pp. 1014-1020. Read before the Califoruift Academy of Scieuces, June 5, 1SS3. i883<5. The Edible Clams of the Pacific Coast, and a Proposed Method of Transplanting Them to the Atlantic Coast. Bn/t. U. S. Fish Com., Vol. Ill, 1883, pp. 353-362, with several figures. Letter to Prof. Spencer F. Baird, U. S. Fish Commissioner, October 14, 1882. 1883^. Description of a New Hydrobinoid Gasteropod from the Mountain Lakes of Nevada, with Remarks on Allied Species and the Physiographical Features of Said Region. Proc. Phil. Acad. Nat. Set. Phila., 1883, pp. 171-176, with figures. 1883a'. Fresh-Water Pearl Mussels. Mining and Scientific Press, San Francisco, April 7, 1883. 1885a. The Giant Clams of Puget Sound. Forest and Stream, May 28, 1885. Read at the Washington, D. C, meeting of the American Fisheries Society, April, 1S65. 1885^5. The Helicidae of the John Day Fauna. Contained in Dr. Charles A. White's paper, "On Marine Eocene, Fresh- Water Miocene, and other Fossil Mollusca of Western North America." Bull. U. S. Geol. Sur., No. 18, 1885, pp. 14-18, PI. III. 1886. The Teredo, or Ship-worm. Am. A'a/., February, 1886, pp. 131-136, with figures. From letter to Prof. Spencer F. Baird, Society Smithsonian Institution. 1887. Ethno-Conchology — a Study of Primitive Money. Rept. U. S. Nat. Mus., 1887, pp. 297-334, Pis. I-IX, and numerous text-figures. i8S9a. Helix (Stenotrema) hirsuta Say on the West Coast. Nautilus, Vol. — , November, 1889, pp.—. 1889^. Notice and Comments on the Distribution of Planorbis (Helisoma) bicarinatus Say. J Vest American Scientist, September, 1889. 1890a. Descriptions of New West American Land, Fresh-Water and Marine Shells, etc. Scientific Results of Explorations by the U. S. Fish Commission Steamer "Albatross." Proc. U. S. Nat. Mus., Vol. XIII, 1890, Pis. XV-XVII, pp. 205-225. 1890^. On the Nishinom Game of " Ha " and the Boston Game of "Props." Am. Anthropologist, October, 1890, pp. 353-358, with figures. 1891a. ^List of American Land and Fresh-water Shells Received from the U. S. Depart- ment of Agriculture, etc. Proc. U. S. Nat. Mus., Vol. XIV, iSgi, pp. 95-106. 360 CALIFORNIA ACADEMY OF SCIENCES. 18913. List of Shells Collected on the West Coast of South America, Principally between Latitudes 7° 30' S., and 80° 49' N., by Dr. W. H. Jones, U. S. Navy. Proc. U. S. Nal. Mus., Vol. XIV, 1891, pp. 307-335. iSgic. Notes on the Sculpture of American Limnteas, etc. Nautilus, Vol. IV, March, 1891, pp. 121-124. 1892^. Patula strigosa Gould, in Arizona. Nautilus, Vol. VI, May, 1892, p. i. 18923. Preliminary Descriptions of New Molluscan Forms from West American Regions. Nautilus, Vol. VI, December, 1892, pp. 85-89. 1893^. Description of a New Species of Nassa (Nassa brunneostoma) from the Gulf of California. Nautilus, Vol. VII, May, 1893, PP- lo-ii. i893(^. Report on the Land and Fresh-water Shells of the Death Valley Expedition. North Avi. Fauna, No. 7, 1893, pp. 269-283. Issued by U. S. Dept. Agric, Division of Ornithology and Mammalogy. i893(:. Preliminary Report on the Molluscan Species Collected by the United States Scientific Expedition to West Africa in 18S9-90. Proc. U. S. Nat. A/us., Vol. XVI, 1893. PP- 317-339- 1893^. On Rare or Little Known Mollusks from the West Coast of North and South America, with Descriptions of New Species. Proc. U. S. Nat. Mus., Vol. XVI, 1893. PP- 341-352. PI- I- 1893^. Report on the Mollusk Fauna of the Galapagos Islands, with Descriptions of New Species. Scientific Results of Explorations by the U. S. Fish Commission Steamer "Albatross." Proc. U. S. Nat. Mus., Vol. XVI, 1893, pp. 353-450, Pis. LI-LII. 1893/". Notes on Recent Collections of North American Land, Fresh-water, and Marine Shells, Received from the U. S. Department of Agriculture. Proc. U. S. Nat. Mus., Vol. XVI, 1893, PP- 743-755- 1894(1. Triodopsis -j- Mesodon, Distribution, etc. Nautilus, Vol. VIII, May, 1894, pp. 6-8. 1894^, 99. Urosalpinx cinereus in San Francisco Bay. Nautilus, Vol. VIII, June, 1894, pp. 13-14; Vol. XII, Feb., 1899, p. 112. 1894c Helix (Arionta) coloradoensis: — A New Locality. Nautilus, Vol. VIII, July, 1894, p. 29. i894(/. The Shells of the Tres Marias and other Localities along the Shores of Lower California and the Gulf of California. Proc. U. S. Nat. Mus., Vol. XVII, 1894, pp. 139-204. 1894^. Mollusk Fauna of the Galapagos Islands. West American Scientist, April, 1894. 1895. A New Variety of Ocinebra circumtexta Stearns. Nautilus,\o\.\y^,]\xn^, 1895, p. 16. 1897. ■ Uvanilla regina — A New Locality. Nautilus, Vol. XI, May, 1897, PP- i-2- 1898a. ■ Description of New Species of ActJeon from the Ouarternary Bluffs of Spanish Bight, San Diego, California. Proc. U. S. Nat. Mus., Vol. XXI, 1898, pp. 297-299, with figures. Also preliminary descriptions in Nnuliltis, Vol. XI, June, 1897, pp. 14-15. 1898^5. Notes on Cytherea (Tivela) crassatelloides Conrad, with Descriptions of Many Varieties. Proc. U. S. Nat. Mus., Vol. XXI, 1898, pp. 371-378, Pis. XXIII-XXV. 1899a'. Crepidula convexa Say, var. glauca Say, San Francisco Bay. Nautilus, Vol. XIII, May, 1899, p.f8. ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 361 1899(5. Natural History of the Tres Marias Islands, Mexico. Nmitihis, Vol. XIII, June, 1899, pp. 19-20. Also in Science, N. S., Vol. X, 1S99, No. 239, p. 1-21. A criticism of Nelson and Goldman's paper in X'. A. Fauna, No. 14. i899<:. Dona.x stultorum Mawe: — Conrad's Species, Cytherea crassatelloides. Nautilus, Vol. XIII, November, 1899, pp. 12>'lb- Contains bibliogr.iphy of this species. 1899^^. Abalone Fishery in California: — Protective Regulation. NauHlus, Vol. XIII, November, 1899, p. 81. i899(f. Modiola plicatula Lamarck, in San Francisco Bay. Naulihcs, Vol. XIII, Decem- ber, 1899, p. 86. See also, Nautilus, Vol. XII, 189S, pp. 102-103. 1899/ Description of a New Variety of Haliotis from California, with Faunal and Geographical Notes. P?oi:. U. S. Nat. il/iis.. Vol. XXII, 1899, pp. 139-142. Also, Nautilus, Vol. XII, 1899, pp. 106-107. 1900^?. Exotic Mollusca in California. Science, N. S., Vol. XI, 1900, No. 278, pp. 655-659. 1900/J. Notes on the Saxidomi of the West Coast. Naiitiltis, Vol. XIV, May, 1900, PP- 1-3- 1900C. The Fossil Shells of the Los Angeles Tunnel Clays. Science, N. S., Vol. XII, 1900, No. 294, pp. 247-250. 1900a'. Vallonia pulchella Miill., in Los Angeles and elsewhere in California. Nautilus, Vol. XIV, October, 1900, pp. 65-67. 1900^'. Fossil Land-Shells of the John Day Region, with Notes on Related Living Species. Proc. Wash. Acad. Sci., Vol. II, 1900, pp. 651-660, PI. XXXV. 1850-52. Stimpson, William. Descriptions of Marine Mollusks. Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1850; Vol. IV, 1851-1852. 1857. Crustacea and Echinoderms of the Pacific Coast, 1S57. 1820-33. SwAiNSON, William. Zoological Illustrations. The shells in 5 parts, 4to, 40 colored plates. London, 1820-1833. 1834. Exotic Conchology, or Drawings of Rare Shells, etc. 4to, 48 plates. London, 1834. Second edition by Hauley, 1841. 1855. Trask, J. B. Descriptions of Californian Fossil Shells. Proc. Cal. Acad. Sci., Vol. I, 1855, pp. 40-42. 1862. Tryon, Geo. W. A Monograph of the Order Pholadacea, etc. i vol.,8vo, i plate. Philadelphia, 1862. 1865-72. Editor American Journal of Conchology. 1865-1872. 7 vols., 8vo, plates. 1879-95. Manual of Conchology, Structural and Systematic. Philadelphia, 1879-1895. Sixteen volumes on marine mollusks, twelve other volumes on land shells. 1882-84. Structural and Systematic Conchology. 3 vols. Philadelphia, 1882-1884. 1S33. Valenciennes, A. Recueil d' Observations de Zoologie, etc. Par Al. de Humboldt et A. Bonpland. Vol. II. Paris, 1833. 1846. Voyage au tour du Monde sur la "Venus" pendant les annees 1836-1839. Par M. du Petit Thouars. 24 plates. Issued in 1846. 1899. Vaughan, T. W. a New Species of Caryophyllia from California. Proc. U. S. Not. A/us., Vol. XXII, 1899, pp. 199-203. ( 46 ) June 2, 1903. 362 CALIFORNIA ACADEMY OF SCIENCES. 1900. The Eocene and Oligocene Coral Faunas of the United States, etc. U. S. Geol. Siirv., Monograph XXXIX. 1894. Watts, W. L. The Gas and Petroleum Yielding Formations of the Central Valley of California. Bull. Cal. St. Min. Bureau, No. 3, 1894. 1897. Oil and Gas Yielding Formations of Los Angeles, Ventura, and Santa Barbara Counties. Bull. Cal. St. Min. Bureau, No. 11, 1897. 1900. Oil and Gas Yielding Formations of California. Bull. Cal. St. Mm. Bureau, No. 19, 1900. 1865. Whitney, J. D. Geological Survey of Califor7iia. Vol. I, Geology. Philadelphia, 1865. 1892. Williamson, Mrs. M. B. An Annotated List of the Shells of San Pedro Bay and Vicinity. Proc. U. S. Nat Mus., Vol. XV, 1892, pp. 179-220, Pis. XIX-XXIIL 1902. A Monograph on Pecten aequisulcatus Carpenter. Bull. So. Cal. Acad. Set., Vol. \, No. 5, May i, 1902, pp. 51-64, Pis. IV-VL 1859^. Wood, William. General Conchology. Royal 8vo, 59 colored plates. Lon- don, 1859. 1859(5. Index Testaceologicus; Catalogue of Shells According to the Linnaean System. 8vo, 2,300 colored figures. London, 1859. 1886-87. Wood, Searles V. Monograph of the Crag Mollusca. 410, 5 parts, 81 plates. London, 1886-1887. 1851. Woodward, S. P. A Manual of the Mollusca; Recent and Fossil Shells, i vol., i2mo, 25 plates and many woodcuts. London, 1857. Later editiou by R. Tate. 1889. Yates, L. G. Stray Notes on the Geology of the Channel Islands. The Mollusca of the Channel Islands of California. Insular Floras, gth Aim. Rept. Cal. St. J^fin., 1889. 364 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE L (all figures magnified.) Fig. I. Turbonilla ( Lancca) pentalopha Dall & Bartsch. Type specimen. Longitude 8.5 mm.; x6. . 274 Fig. \a. Same. Nuclear whorls more enlarged. 274 Fig. 2. Turbonilla (Pyrgolampros) gibbosa Carpenter. Longitude 5.6 mm. ; X9.3- 279 Fig. 2a. Same. Nuclear whorls more enlarged. 279 Fig. 3. Odosto7nia ( Oscilla) esquisculpta Carpenter. Type specimen, not fully mature. Longitude 2 mm. ; xi3. 284 Fig. 3a. Same. Nuclear whorls more enlarged. 284 Fig. 4. lurbonilla ( Pyrgisais) auricoma Dall & Bartsch. Type specimen. Longitude 7.2 mm.; x6.2. 274 Fig. 4a. Same. Nuclear whorls more enlarged. 274 Fig. 5. Tit? bonilla (Pyrgolampros) lozvei Da'L'L & ^ARTSCU. Type specimen. Longitude 7.2 mm.; x6.2. 278 Fig. 5a. Same. Nuclear whorls more enlarged. 278 Fig. 6. Odostomia ( Oscilla) grammatospira Dall & Bartsch. Tj'pe specimens. Lon- gitude 5.3 mm.; xio. 285 Fig. ba. Same. Nuclear whorls more enlarged. 285 Fig. 7. Turbonilla (Pyrgolampros) arnoldi Dall & Bartsch. Type specimen. Lon- gitude 7.6 mm. ; x6.2. 279 Fig. 8. Odostomia ( Chrysallida) diegensis Dav.\^ & 'RA.v.TScn. Type specimen; the lower right-liand portion of the aperture defective. Longitude 4 mm.; xu- 284 Fig. 9. Turbonilla (Pyrgolampros ) adleri Dall & Bartsch. Type specimen; the apex defective. Longitude 9.3 mm.; X5- 280 Fig. 10. Turbonilla (Strioturbonilla) iorquala var. stylina Carpenter. Longitude 8 mm.; X7-25. 272 Fig. \oa. Same. Nuclear whorls more enlarged. 272 Fig. II. Odostomia (Amaura) tiuciformis vat. avellana Carpenter. Type specimen. Longitude 9. 1 mm.; X5. 283 Fig. 12. Odostomia ( Evalea) stearnsii Dall & Bartsch. Type specimen. Longitude 5.2 mm.; X9. 2. 282 Fig. 13. Odostomia (Amaura) pupi/ormis Carpenter. Type specimen. Longitude 6.5 mm.; X7. 283 Fig. 14. Odostomia tenuis Carpenter. Longitude 5.7 mm.; x8. 281 Fig. 15. Odostomia (Evalea) gouldii Carpenter. Longitude 5 mm.; X9. 282 Me^idirs Cal Acad. Sci. Vdl. hi. 3« 4<» [AhndldJ Plate I 5 ct 6 «• 13 14- PHUIO ■UEH.HBnTDM ft HEY, B J". 366 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE IL (all figures MAGNIFIED.) Tiirbonil/a ( Lancea) tridenlata Carpenter. Longitude 12. 8 mm.; X5. 273 Same Nuclear whorls more enlarged. 273 Turbonilla (Pyrgiscus) subcuspidata Carpe.VTER. Type specimen. Longitude 6 mm.; xg. 277 Same. Nuclear whorls more enlarged. 277 Turbonilla ( Pyrgolampros) lowei var. pedroana Dall & Bartsch. Type speci- men. Longitude 5.5 mm.; xio. 279 Same. Nuclear whorls more enlarged. 279 Turbonilla lorquata Gould. Longitude 10.6 mm.; x6. 271 Same. Nuclear whorls more enlarged. 271 Turbonilla stearnsii Dall & Bartsch. Type specimen. Longitude 9.2 mm.; X6.7. 271 Same. Nuclear whorls more enlarged. 271 Turbonilla ( Pyrgiscus) crebrifilata Carpenter. Longitude 5.4 mm.; xto.7. 276 Same. Nuclear whorls more enlarged. 276 Turbonilla (Pyrgiscus) tenuicula Gould. Longitude 6.1 mm.; xg. 275 Same. Nuclear whorls more enlarged. 275 Fig. 8. Ttirbonilla ( Pyrgisculus) laminata Carpenter. Longitude 6.8 mm.; xg. 277 Fig. 8a. Same. Nuclear whorls more enlarged. 277 Fig. I. Fig. \a. Fig. 2. Fig. ia. Fig. 3- Fig. 3«- Fig. 4- Fig. 4a. Fig. 5- Fig. 5«- Fig- 6. Fig. ba. Fig. 7- Fig. ^a. Mehqirs Cal^Acad. Sci. Vdl. iii. [AhndldJ Fiate II. la. i«- puoTQ -iiTH HanroK s bev. s j; 368 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE IIL Fig. I. Paracyatkus pedroensis Vaughan. View of calice. Greater diameter 12 mm.; X2.8. 88 Fig. \a. Same. Upright view of corallum. Height 18 mm.; xi.2. 88 Fig. 2. CaryophyUia ca/ifornica Vkughan. ViewofcaHce. Greater diameter 1 1.5 mm. ; X2.7. 87 Fig. 2a. Same. Upright view of corallum. Height 13 mm.; xi-2. 87 Fig. 3. Caryophyllia pedroe?isis V KVGHkN. View of calice. Greater diameter 13.5 mm. ; X2.6 87 Fig. T,a. Same. Upright view of corallum. Height 25.5 mm.; xi.2. 87 Fig. 4. CaryophylUa anioldi V A\!onA.n. Upright view of corallum. Height 16.5 mm.; X2.5. Fig. 4a. Same. View of calice. Greater diameter 16 mm.; X2.5. 86 Fig. 5. Turbonilla ( Pyrgiscus) lalifH>idiaDKi.i. & ^KKTSCH. Type specimen. Longitude 5.8 mm.; X7.4. 275 Fig. 5*. Same. Nuclear whorls more magnified. 275 86 Memoirs Cal.Acad.5ci.Vdl. in. [Arndluj Plate III 3 a ■to. PHara-UTH BHITTDN ft KEY. ST. 370 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE IV. Fig. I. Nassa cerritensis, sp. nov. Upper San Pedro series, Los Cerritos. Type specimen. Longitude 31 mm.; Xi.S- 231 Fig. 2. Volvula cylindrica Carpenter. Lower San Pedro series, Deadman Island. Lon- gitude 7 mm.; X2. 191 Fig. 3. Nassa ca/iforttiana CoNRAD. Upper San Pedro series, San Pedro. Longitude 38 mm.; X3- 231 Fig. 4. Bitlhim californiawi Dall & Bartsch. Lower San Pedro series, San Pedro. Longitude 5.6 mm. ; X4. 291 F'&- 5- Siphonalia kellettii Forbes. Upper San Pedro series, San Pedro. Longitude 112 mm. ; natural size. 229 Fig. 6. Nassa versicolor var. hooveri, var. nov. Upper San Pedro series, San Pedro. Type specimen. Longitude 14 mm. ; X2.7. 362 Fig. 7. Fustis riigosus Trask. Lower San Pedro series, Deadman Island. Longitude 50 mm. ; X1.3. 226 Fig. 8. Seila assintilata C. B. Adams. Lower San Pedro series, San Pedro. Longitude ID mm.; X4- 290 Fig. 9. Marginella ( Volvarina) varia Sovverbv. Lower San Pedro series, Deadman Island. Longitude 9.2 mm. ; X2-6. 222 Fig. 10. Mitromorpha internicdia, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 9.6 mm.; X4- 223 Fig. II. Bitiimn riigatum Carpenter. Upper San Pedro series, San Pedro. Longitude 13 mm ; X3-i- 295 Fig. 12. Rissoa acutelirata Carpenter. Upper San Pedro series, San Pedro. Longitude 2.1 mm.; X6.7. 305 Fig. 13. Ttirri/el/a Jewe/tii C\K?B.nTRTL. Pliocene, Deadman Island. Longitude 69 mm.; natural size^ 300 Fig. 14. Odostomia ( /vara) lerricula (Carpenter) D. & B. Lower San Pedro series, Deadman Island. Longitude 4 mm.; X6-7- 285 Fig. 15. Fusus barbare7isis Trask. Pliocene, Deadman Island. Longitude 50 mm.; X1.5. 224 Memoirs CalAcad^ 5ci . Ydl. hi. [Arndkd] Plate T/ 13 4 M'm ?liDTQUTH BR'.TTITi t HTV 5T 372 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE V. Fig. I. Ocinebra barbarensis Gabb. Lower San Pedro series, Deadman Island. Lon- gitude 19 mm.; X2. 254 Fig. 2. Ocinebra poiilsoni Nuttall. Upper San Pedro series, San Pedro. Longitude 31 mm. ; X2.7. 260 Fig. 3. Scala tincta Carpenter. Upper San Pedro series, San Pedro. Longitude 19 mm.; X2. 265 Fig. 4. Scala indianoium Carpenter. Upper San Pedro series, San Pedro. Longi- tude 21 mm.; X2. 264 F'g- 5- Ocinebra lurida var. cerriiensis, var. nov. Upper San Pedro series. Crawfish George's. Type specimen. Longitude 17 mm.; Xi.3. 258 Fig. 6. Colianbel/a (^^sopus) chrysalloidea Carpenter. Upper San Pedro series, San Pedro. Longitude 11 mm.; X 2. 237 Fig. 7. Pleuroioma ( Borsonia) bartsc/ii, sp. nov. Lower San Pedro series, Deadman Island. Short variety. Longitude 14 mm.; Xi-3- 200 Fig. 8. Drillia hcmphilli Stearns. Upper San Pedro series, San Pedro. Longitude 16 mm.; X2.5. 204 Fig. g. Ocinebra keepi, sp. nov. Upper San Pedro series, Deadman Island. Type specimen. Longitude 35 mm.; X2. 256 Fig. 10. Drillia inermis Hinds. Upper San Pedro series, San Pedro. Longitude 22 mm.; Xi.25. 205 Fig. II. Amphissa ventricosa, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 13 mm.; X2. 242 Fig. 12. Ocinebra lurida var. aspcra Baird. Upper San Pedro series, San Pedro. Lon- gitude 28 mm.; X2. 257 Fig. 13. Margarita optabilis var. nodosa, var. nov. Lower San Pedro series, San Pedro. Type specimen, tilted back. Altitude 6.9 mm.; X4. 332 Fig. 14. Margarita optabilis var. knechti, var. nov. Lower San Pedro series, San Pedro. Type specimen, tilted back. Altitude 8 mm. ; X3- 332 Fig. 15. Ocinebra micheli Ford. Upper San Pedro series. Crawfish George's. Longitude 16 mm.; X2.5. 259 Fig. 16. Margarita parcipicia var. pedroana,vAr. nov. Lower San Pedro series, San Pedro. Type specimen, tilted back. Altitude 5.5 mm.; X4. 333 Memoirs Cal.Acad. 5ci. Vdl. hi. [ArndldJ FlkteY %^ PHOTQ -UTH HRnrCM K HEY. ST 374 CALIFORNIA ACADEMY OF SCIENCES. Fig. 2. Fig. 3- Fig. 4 Fig. 5- Fig. 6. EXPLANATION OF PLATE VL Fig. I. Tritoninm ( Pricne) oreg07iensis Redfielo. Pliocene, Deadman Island. Longi- tude I02 mm.; natural size. 286 Pleurotoma ( Borsonia) dalli, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 23 mm. ; X2. 201 Mangilia itilerfossa var. pedroana, var. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 6 mm.; XS- 213 Ttophon ( Borco/rophon) shiarti Smith. Pliocene, Deadman Island. Longitude 30 mm.; X2. 252 Trophon ( Boreotrophon) orpheus var, pmairsor, var. nov. Pliocene, Deadman Island. Type specimen. Longitude 15 mm.; X2.7. 253 Trophon ( Boreotrophrn) crrritetisis, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 32 mm.; X2. 249 Fig. 7. Columbella (Alsopns) oldroydi, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 8.5 mm.; X2.6. 238 Fig. 8. Trophon (Boreotrophon) gracilis Perry. Pliocene, Deadman Island. Longitude 26 mm.; X2. 250 Fig. 9. Trophon ( Boreotrophoii) mulHcosfatus EsCHSCHOLTZ. Lower San Pedro series, Deadman Island. Longitude 10 mm.; X2.6. 251 Fig. 10. Trophon (Boreotrophon) scalariformis GouLD. Lower San Pedro series, Deadman Island. Longitude 15.5 mm.; X2-6. 252 Fig. II. Bittitim williamsoni, sp. nov. Upper San Pedro series, San Pedro. Type speci- men. Longitude 2.9 mm.; X7-2. 295 Fig. 12. Trophon (Boreotrophon) pedroana, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 12 mm.; X3-3. 251 Fig. 13. Pteurototna ( Spirolropsis) sniithi, sp. nov. Pliocene, Deadman Island. Type specimen. Lonj^jitude 36 mm.; X1.5. 216 Fig. 14. Bittium (Styliferina) temcisadpta Carpenter. Lower San Pedro series, Deadman Island. Longitude 6.1 mm.; X4. 296 Fig. 15. Mangilia intrrlirata Stearns. Lower San Pedro series, Deadman Island. Lon- gitude 9.1 mm.; XS- 213 Fig. 16. Mangilia oldroydi, sp. nov. Lower San Pedro series, Deadman Island. Type k specimen. Longitude 16. 1 mm.; X2.5. 213 Fig. 17. Mangilia scutpliirataT) A'Li.. Pliocene, Deadman Island. Longitude 1 1 ram ; X 3- 214 Memoirs Cal km. Sci . Vdl. hi. [Arnold J Plate ^71. 15 PEDin -UTH HBTTTCS It SEY. ST. 376 CALIFOKNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE VIL Fig. I. Murex ( Chicorejis) leea7ius Y)p^\A,. Upper San Pedro series, San Pedro. Longitude 55 mm.; Xi.3- 243 Fig. 2. Solaris lla per amabilis Carpenter. Pliocene, Deadman Island. Altitude 14 mm.; Xi-5- 335 Fig. 3. Pleurotoma ( Dolichotoma) cooperi, sp. nov. Upper San Pedro series, San Pedro. Longitude 64 mm. ; natural size. 203 Fig. 4. Admele gracilior Carpenter. Lower San Pedro series, Deadman Island. Lon- gitude 10.5 mm. ; X3-3. 219 Fig. 5. Cancellaria tritoyiidea Gabb. Upper San Pedro series, San Pedro. Longitude 90 mm.; natural size. 218 Fig. 6. Chrysodomus tabulalus Baird. Pliocene, Deadman Island. Longitude 80 mm.; natural size. 228 Fig. 7. Chrysodomus rectirostris Carpenter. Lower San Pedro series, Deadman Island. Longitude 28 mm.; X2. 228 Fig. 8. Cancellaria cooperi Gabb. Upper San Pedro series, San Pedro. Longitude 80 mm.; natural size. 217 Fig. 9. Mangilia angulata Carpenter. Lower San Pedro series, Deadman Island. Lon- gitude 8 mm.; X3-6. 212 Fig. 10. Bela fidicula Gould. Lower San Pedro series, Deadman Island. Longitude 1 1 mm.; X4- 209 Fig. II. Solariclla cidaris Carpenter. Pliocene, Deadman Island. Altitude 42 mm.; natural size. 334 ;'L Acad. 5ci. Vol. Ill [Arnold] Plate VII f^- .-^X "^v s^«f ^BTO -ilTK BIUTTOK «: HEY. B F. 378 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE VIIL Fig. I. Mavgilia pamei, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 12.5 mm ; X3-4. 214 Fig. 2. Palndestrina curia, sp. nov. Lower San Pedro series, San Pedro. Type specimen. Longitude 3.8 mm.; X7. 305 Fig. 3. Paludestrina stokesi, sp. nov. Lower San Pedro series, San Pedro. Type speci- men. Longitude 4.6 mm.; X 5 4- 305 Fig. 4. Dentalium indianonim Carpenter. Lower San Pedro series, Deadman Island. Longitude 38 mm.; natural size. 186 Fig. 5. Drillia renaiidi, sp. nov. Lower San Pedro series, Deadman Island. Type speci- men. Longitude 16 mm.; X3. 208 Fig. 6. C{zciim californicum Dall. Lower San Pedro series, Deadman Island. Longitude 2.9 mm.; X5.8. 297 Fig. 7. Dri/lia merriatni, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 14 mm.; X3-2. 207 Fig. 8. Bulla quoyi Gray. Upper San Pedro series, San Pedro. A young specimen. Longitude 8 mm.; X3- '93 Fig. 9. Eiipleura murici/ormis var. curia, var. nov. Upper San Pedro series, San Pedro. Type specimen. Longitude 15 mm.; X3.2. 249 Fig. 10. Ccscum crebricinctian Carpenter. Lower San Pedro series, San Pedro Bluff. Longitude 5.5 mm.; X6. 298 Fig. II. Lacuna solidiila (Loven) Carpenter. Upper San Pedro series, San Pedro. A somewhat decorticated specimen. Longitude 10 mm.; X2.5. 303 Fig. 12. Dentalium pse^idohexagonum Dall. Lower San Pedro series, Deadman Island. Longitude 15.5 mm. ; X3' 186 Fig. 12a. Sectional view of same; X3- 186 Fig. 13. Drillia pudica Hinds. Upper San Pedro series, San Pedro. Longitude 11 mm ; X3-5- 208 Fig. 14. Bela saiicta-mottica, sp. nov. Lower San Pedro series (Pleistocene), Port Los Angeles. Type specimen. Longitude 12 mm.; X3. 210 Fig. 15. Cadulus nitentior Carpenter. Lower San Pedro series, Deadman Island. Lon- gitude 10 mm.; X3.3- 187 Fig. 16. CcBcum inagnum Stearns. Lower San Pedro series, Deadman Island. Longitude 4.7 mm.; X5-3- 298 Fig. 17. Drillia johnsoni, sp. nov. Upper San Pedro series, San Pedro. Type specimen, apex broken olT. Longitude 29 mm. ; X2. 206 Fig. 18. Haininca virescens .Sowerby. Upper San Pedro series, San Pedro. Longitude 7 mm.; X3-25- '94 Mehdirs D\l.Acad.5cl Vdl.iii. [AhndldJ Hate VIII if" 16 14 12 « FHDXOrUrH BHIITON R HEY. ST. 580 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE IX. Fig. I. Pleurotoma ( Borsonia) bartschi, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 18.5 mm.; X3-4- 200 Fig. 2. Bitlium qiiadrijilaiiim Carpenter. Lower San Pedro series, Deadman Island. Longitude 10 mm.; X3- 292 Fig. 3. Ma7igilia striosa C. B. Adams. Upper San Pedro series, Los Cerritos. Longitude 9.4 mm.; X3- 215 Fig. 4. Pleurotoma ( Leiccosyrmx) pedroana, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 17 mm.; X3. 202 Fig. 5. Mangilia kooveri, sp. nov. Upper San Pedro series, San Pedro. Type specimen. Longitude 11 mm.; X3. 212 Fig. 6. Act(Z07i ( Rictaxis) puncloccelaia Carpenter. Upper San Pedro series, San Pedro. Longitude 5.9 mm.; X3. 189 Fig. 7. Mangilia ( Taranis) sfrongi, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 12 mm.; X3-5. 215 Fig. 8. Columbella ( Anackis) mi7iima, s]i. nov. Upper San Pedro series, San Pedro. Type specimen. Longitude 5.5 mm.; X3. 237 Fig. 9. Eulima hastata Sovverby. Upper San Pedro series, San Pedro. Longitude ID mm.; X3-4- 268 Fig. ID. Mangilia (Cythara) bratitieri, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 10 mm.; X3.2. 211 Fig. II. Ocinebra hirida vax. cancellina Philippi. Upper San Pedro series, San Pedro. Longitude 21 mm.; X2. 257 Fig. 12. Eulima 7>ticans Carpenter. Lower San Pedro series, Deadman Island. Longi- tutle 12 mm.; X3-5. 269 Fig. 13. Pla7iorbis tu77iidus Pfeiffer. Upper San Pedro series, San Pedro. Maximum diameter 12.7 mm.; X3. 195 Fig. 14. Pla/iorbis vermicularis GouLD. Upper San Pedro series, San Pedro. Maximum diameter 1 1.5 mm.; X3- I95 Fig. 15. Euli//ia falcala Carpenter. Lower San Pedro series, Deadman Island. Longi- tude 7 mm.; X3. 268 Fig. 16. Eupletira 77iuricifor77iis Broderip. Upper San Pedro series, San Pedro. Longi- tude 33 mm. ; natural size. 248 Fig. 17. Scala bellastriata CKlLVE.TflTR'R.. Figure of living shell from .San Pedro. Longitude 18 mm.; X2. 263 Memoirs CalAcad. Sci. Ydl. hi. [ArndldJ Elate IX. PHcm-iJiH BBrrrcri k key. sj". 382 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE X. Pleurotoma ( Borsonia) hooveri, sp. nov. Lower San Pedro series, Deadman Island. Type specimen. 12.7 mm.; X3. 201 Phorciis pidligo Martyn. Upper San Pedro series, Crawfish George's. Speci- men slightly tilted back. Altitude 17.5 mm.; natural size. 328 Tornatina culcitella Gould. Lower San Pedro series, Deadman Island. Longitude 1 1 mm. ; X3-2. 190 Columbella solidula var. precursor, var. nov. Upper San Pedro series, San Pedro. Tyi^e specimen. Longitude 14.4 mm.; XS-S- 236 Tornatina cerealis Gould. Lower San Pedro series, San Pedro. Longitude 4.5 mm.; X5-5- 189 Actizon (raskii SlRhRT^iS. Upper San Pedro series, San Pedro. Longitude 14 mm.; X3- 188 Columbella ( Astyris) iuberosa Carpenter. Upper San Pedro series, San Pedro. Longitude 6.5 mm. ; X3. 240 Columbella (Astyris) gausapata Gould. Upper San Pedro series, San Pedro. Longitude 10 mm.; X3- 239 Columbella (Astyris) califotniana Gaskoin. Lower San Pedro series, Deadman Island. Longitude 10 mm.; X3. 238 Columbella (Astyris) gausapata var. carinata Hinds. Upper San Pedro series, San Pedro Longitude 7.7 mm. ; X3- 240 Tornatina eximia Baird. Pliocene, Deadman Island. Longitude 12.5 mm.; X3- 190 Polynices ( Neverita) recbiziana Petit. Upper San Pedro series, San Pedro. Typical shape. Altitude 17.5 mm.; natural size. 314 Natica (Cryptonatica) clausa Broderip & SowERBY. Pliocene, Deadman Island. Shouldered variety. Altitude 26 mm.; natural size. 313 Polynices ( Lunatia) Icwisii GouLD. Upper San Pedro series, San Pedro. Lon- gitude 75 mm. ; X0.66. ■ 315 Margarita pupilla G0VI.U. Pliocene, Deadman Island. Altitude 7.5 mm.; X3- 333 Delphinoidea coronadocnsis, sp. nov. Pleistocene, Spanish Bight, San Diego. Type specimen, view from above. Maximum diam. 2 mm.; XS- 320 Same specimen viewed from in front; XS- 320 Cylichna alba Brown. Lower San Pedro series, Deadman Island. Longitude 12 mm. ; X 1.5. 192 Fig. 19. Chlorostonia montereyi Kiener. Upper San Pedro series, Crawfish George's. Specimen slightly tilted back. Altitude 28 mm. ; natural size. 326 Fig. I. Fig. 2. Fig. 3- Fig. 4- Fig. 5- Fig. 6. Fig. 7- Fig. 8. Fig. 9- Fig. 10. Fig. 1 1. Fig. 12. Fig. 13- Fig. 14. Fig. 15- Fig. 16. Fig. 17- Fig. 18. Memoirs Cal.Acad.5ci.Vdl. hi [AhndldJ Piate X, 10 17 19 --^ ^iot!wen's 'Coi^RAV. Upper San Pedro series, San Pedro. Exterior of left valve. Altitude 20.5 mm. ; xi-3- 112 Fig. 4a. Same specimen. Outline, showing convexity of same valve; XI.3. 112 Fig. 5. Pecten (Pecten) diegcnsis Dall. Living shell, Monterey. Outline, showing con- vexity of right valve (which is the same as the convexity of the right valve of P. stearnsii'). Altitude 72 mm.; natural size. 106 Fig. 6. Pecten ( Chlamys) jordani, sp. nov. Pliocene, Deadman Island. Type specimen, exterior of right valve. Altitude 51 mm. ; X0.9. iii Fig. 7. Same specimen, exterior of left valve; xo.g. 11 1 Fig. 8. Pecten (Chlamys) taliauritus var. fragilis, var. nov. Upper San Pedro series, San Pedro. Type specimen, exterior of right valve. Altitude 25 mm. ; Xi-3. H2 Memoirs CjlAcaj]. 5ci. Ydljii. l_r'.." riijj.ijj riJ\lL, j\Ll &0^ // M 4« a -TITH EKHTDK R BEY. B.r. 388 CALIFORNIA ACADEMY OF SCIENCES. Fig. r. Fig. 2. Fig. 3- Fig. 4- Fig. 5- Fig. 6. Fig. 7- Fig. 8. Fig. 9- EXPLANATION OF PLATE XIIL Cooperella subdiaphana Carpenter. Lower San Pedro series, Deadman Island. Interior, showing hinge. Longitude 12.5 mm.; XS- i53 Callista subdiaphana var. pedroana, var. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 33 mm.; xo.8. 144 Aligeva cerritensis, sp. nov. Upper San Pedro series, Los Cerritos. Type speci- men, view of interior. Longitude 10.9 mm.; X3. 138 Callista subdiaphana Carpenter. Pliocene, Deadman Island. Longitude 45 mm.; XO.S. 144 Psephis laJitilla GoV'LD. Lower San Pedro series, Deadman Island. View of inte- rior. Longitude 6 mm. ; X4. 133 Pecten ( Paiinopccten) caurinus Gould. Pliocene, Deadman Island. Exterior of left valve. Altitude 122 mm.; xo.8. 107 Tellina ( Moerella) sahnonea Carpenter. Lower San Pedro series, Deadman Island. Interior of right valve. Longitude 14 mm. ; X3.3. 157 Donax lavigata Deshaves. Upper San Pedro series, San Pedro. Interior view. Longitude 21 mm.; X2.5. 170 Donax californica Conrad. Lower San Pedro series, Deadman Island. Interior view. Longitude 17 mm.; X2.5. 170 Memdirs Cal Acad. 5ci . Vol. in. [ArndldJ PlATE Ml. .iim>*»^^*^^ puoTD-UTH BKrrroriitHEy.ST, 390 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE XIV. Fig. I. Vetius (Chione) succincla Valenciennes. Upper San Pedro series, San Pedro. Exterior of right valve. Longitude 54 mm.; natural size. 149 Fig. 2. Venus ( Chione) fludifraga Sowerbv. Upper San Pedro series, S;»n Pedro. E.x- terior of right valve. Longitude 25 mm.; xi-?- I47 Fig. 3. Vemts (CAwne) negleda Sowerby. Upper San Pedro series, San fedro. Lon- gitude 30 mm.; X2.2. 148 Fig. 4. Tapes staminea Conrad. Upper San Pedro series, San Pedro. Longitude 50 mm.; natural size. 150 Fig. 5. Tapes lacineata Carpenter. Upper San Pedro series, Los Cerritos, Longitude 10 mm.; x i.i- 150 Fig. 6. Tapes tenerrima Carpenter. Upper San Pedro series, San Pedro. Longitude 84 mm.; natural size. 151 Memoir VlJ L_Y-_i_..i ^r^x^. All. [AhndldJ Hate IN. PHcro rinH-HHrrroK « bey. bt. 392 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE XV. Fig. I. Fig. la. Fig- 2. Fig. 3- Fig. 4- Fig. a,a. Fig. 5- Fig. 6. Fig. 7- Fig. 8. Fig. 9- Semele puldira Sowerby. Upper San Pedro series, San Pedro. Longitude 15 mm. ; X3 3. 166 Same. Outline, showing convexity of valve; X3-3. 166 Tellina {Angu/us) buttotii D.\ll. Upper San Pedro series, San Pedro. Interior view. Longitude 13.5 mm. ; X4.6. 157 Same as fig. 2. E.xterior view; X46. 157 Semele pulchra var. fitoiilereyi, var. nov. Lower San Pedro series, Deadman Island. Longitude 14 mm.; X3.3. 166 Same. Outline, showing convexity of valve; X3.3. 166 Thyasira bisecta CoNRAD. Pliocene, Deadman Island. Longitude 74 mm. ; XI. I. 135 Cardium {Ringicardmm) procerum Sowerby. Upper San Pedro series, San Pedro. Exterior view. Longitude 73 mm.; natural size. 139 Tellina i^Angulus) idee Dall. Upper San Pedro series, Los Cerritos. Longitude 62 mm.; X0.7. 158 Tellina {Angnhis) bodegetisis Hinds. Upper San Pedro series, San Pedro. Longitude 50 mm. ; natural size. 158 Tellina (Angvlus) rnbescens Hanley. Ufjper San Pedro series, San Pedro. Longitude 42 mm.; natural size. 159 Memoirs Cal Acffl. 5ci . Ydl. hi [Arndld] Plate TY I a PHOTO -UrHBBITTaN R REV. BF. 394 CALIFOENIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE XVL Fig. I. Macoma indenlala Carpenter. Upper San Pedro series, Los Cerritos. Longitude 50 mm.; natural size. 161 Fig. 2. Macoma calcarea Gmelin. Lower San Pedro series, Deadman Island. Longitude 18 mm. ; X2.3. 161 Fig. 3. Macoma nasuta Conrad. Upper San Pedro series, San Pedro. Large, typical specimen. Longitude 75 mm.; natural size. 163 Fig. 4. Macoma inquinaia Deshayes. Upper San Pedro series, San Pedro. Longitude 42 mm.: natural size. 162 Fig. 5. Macoma secta Conrad. Upper San Pedro series, San Pedro. Longitude 82 mm.; natural size. 164 Fig. 6. Macoma yoldiformis Carpenter. Lower San Pedro series, Deadman Island. Longitude 24 mm.; natural size. 165 Fig. 7. Ve)ius {C/iione) g7iidia Broderip & Sowerby. Upper San Pedro series, San Pedro. Exterior of right valve. Longitude 96 mm.; natural size. 147 Memoirs L?LMm. Sci. Ydl. iii [ArndldJ Plate XVI ' £~—J^%"?^ FHcrn-uniBKnTr: rhet.bf. 396 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE XVIL Fig. I. Tercbratalia hemphilli Dall. Pliocene, Santa Barbara. View of pedicle valve. Longitude 57 mm. ; xo.6. 92 Fig. 2. Same. Lateral view of both valves; xo.6. 92 Fig. .3. Same. View of brachial valve; xo.6. 92 Fig. 4. Leda hamata Carpenter. Lower San Pedro series, Deadman Island. Longitude 9.5 mm.; X4-5- 97 Fig. 5. Leda iaphria Dall. Lower San Pedro series, Deadman Island. Longitude 9.6 mm.; X4. 98 Fig. 6. Leda vihmta var. prescursor, var. nov. Lower San Pedro series, Deadman Island. Type specimen. Longitude 9 mm.; X5. 97 Fig. 7. Leda fossa Baird. Lower San Pedro series, Deadman Island. Longitude 13.5 mm.; x3-2. 96 Fig. 8. Mytilimeria nuttalli Conrad. Lower San Pedro series, Deadman Island. Altitude 17 mm. ; x 1.4. 126 Fig. 9. Terebratalia smilhi, sp. nov. Pliocene, Deadman Island. Type specimen. Alti- tude 50 mm. ; natural size. 93 Fig. 10. Verdcordia tiovemcoslata Adams & Reeve. Lower San Pedro series, Deadman Island. Longitudes mm- 1 X4.5. 126 Fig. II. Corbiila luteola Carpenter. Lower San Pedro series, Deadman Island. Longi- tude 8 mm.; X3. 181 Fig. 12. Bornia retifera Dall. Lower San Pedro series, Deadman Island. Interior view, showing hinge. Longitude 7.5 mm.; X4. 136 Fig. 13. Yoldia scissiirata Dall. Lower San Pedro series, Deadman Island. Longitude 12.7 mm.; X4. 99 Memdirs Cal.Acad. Sci. VDL.in. [ArndldJ Piate XVIL 10 <53?5>- \'i PHDTD -UTH BHTrraK It HEY. GT, 398 CALIFOKNIA ACADEMY OF SCIENCES EXPLANATION OF PLATE XVIIL Fig. I. Kellia suborbiailaris Montagu. Lower San Pedro series, Deadman Island. Interior view of left valve. Longitude 8 mm. ; X4-3. 137 Same specimen. Outline, showing convexity of valve; X4.3. 137 Pandora { Ke7uierlia) bicarmata Carpenter. Lower San Pedro series, Deadman Island. View of imperfect left valve. Longitude 14 mm. ; X3. 123 Pandora {Kennoiia) Jilosa Carpenter. Lower San Pedro series, Deadman Island. Left valve. Longitude 15 mm.; X3. 124 Area lahiata Sowerby. Upper San Pedro series, San Pedro. Longitude 28 mm.; XI. 3. lOI Diplodonta serricata Reeve. Upper San Pedro series, San Pedro. I^ongitude 10.2 mm.; x3-3- '34 Same. Outline, showing convexity of valve; X3.3. 134 Nttcula suprasiriata Carpenter. Upper San Pedro series, Los Cerritos. Longi- tude 7 mm.; X4.7- 96 Fig. 7. Kellia laperousii Deshayes. Lower San Pedro series, Deadman Island. Interior view. Longitude 23 mm. ; X2. 137 Same. Outline, showing convexity of valve; X2. 137 Diplodonta orbella Gould. Lower San Pedro series, Deadman Island. Longitude 9.2 mm.; X3.3. I34 Same. Outline, showing convexity of valve; X3.3. 134 Glycymeris barbamisis Conrad. Upper San Pedro series, San Pedro. View of interior. Longitude 25 mm. ; xi-3- 100 Glycymeris septcntrionalis Middendorff. Upper San Pedro series, San Pedro. View of interior. Longitude 22 mm. ; xi-3. loi Ne^ra pec f inula CKKPKtiTKV.. Lower San Pedro series, Deadman Island. Imper- fect valve. Longitude 6.5 mm. ; X5.4. tSi Astarte {Crassinella) branneri sp. nov. Upper San Pedro series, Los Cerritos. Type specimen, interior view. Longitude 11. 2 mm. ; X2.7. 127 Fig. Fig. \a. 2. Fig. 3- Fig. 4- Fig- 5- Fig. Fig. 5«- 6. Fig. 7«- Fig. 8. Fig. 8a. Fig. 9- Fig- 10. Fig. II. Fig. 12. Memoirs Cal Acad. Sci . Vdl. hi. [Ah;i._ 0" 10 PHOTD-UTH BfirrrCKKHEV, BT 400 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE XIX. Fig. I. Madra {Spisu/a) falcata Gould. Upper San Pedro series, San Pedro. Interior of left valve. Longitude 47 mm.; natural size. 176 Fig. 2. A/adra californica Conrad. Upper San Pedro series, San Pedro. Interior of left valve. Longitude 39 mm. ; natural size. 174 Fig. 3. Madra hemphilli Dall. Upper San Pedro series, San Pedro. Interior of right valve. Longitude 124 mm; natural size. 175 Fig. 4. Madra exoleta Gray. Upper San Pedro series, San Pedro. Interior view, right valve. Longitude 57 mm.; natural size. 175 Fig. 5. Madra {Spisula) catilliformis Conrad. Upper San Pedro series, San Pedro. In- terior of right valve. Longitude 125 mm.; natural size. 176 Memoirs Cal.Acad. Sci. Ydl.iii. [ArndldJ Plate XIX FKDTa -mH,HBJTTaK. * KEY. S F. 402 CALIFOENIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE XX. Cardium {Lavicardium) elatum SowERBY. Upper San Pedro series, San Pedro. Exterior of left valve. Altitude 167 mm.; natural size. 141 Memdirs Cal-Acad. Sci. Vdl.hi, [Arndld] Plate XX. PHDXD -TJTH HRTTTDK R HET. ST, 404 CALIFORNIA ACADEMY OF SCIENCES. EXPLANATION OF PLATE XXL Fig. I. Pecten bcllus Conrad. Pliocene, Santa Barbara. Left valve of Gabb's type speci- men of Janira bella (No. 960, Collection Academy of Natural Sciences, Phila- delphia). Altitude 80 mm., slightly enlarged. 103 Fig. 2. Same. Right valve. 103 Memoirs CAL/^rAD.Sci.VDLiii. [ArndldJ Plate XXI. Ih^'B, Z. FKOiD-urH BHrrroK k hey. s.r. 6 ii 2 < < o az Li_ DC LlJ II CO O or Q LU Q_ < en '"'.if hill I'll''!' mm I'li'i' '^v/; ^ -J D JZ3 m ^ La CD "O o b c (0 < ni (0 tE Q >, n (1) r (1) a m 1- m ffl o 01 o r m Q. 0) r 0) () o X) o E "O (0 o Q "D a> CL CO (0 ^III. H^^^Ki^dHltett. ^ ^^^^^^^^^^^^^^P Bft ^^^^^^^^^^^^^^^^^^^^^? ' jt-^^^^^^^^^M ^^^^^^^^^^^ /■^^ ^^^^^^^^^^^^M ^^^^^^^^^^^^^^L^jt3-^ -* /^^^^^^^H ^^^^^^^^^^^^^^^^^^^^^^^^^^^v i^ ^S '' v^'ii:..'^"-?'.^^! ^^^^^^^^^^^^^B I ';iA.JK^_r ' '^^P-'''^' ' ^H ^^^^H \ ^ ^ -vk-^^iiLr^ .^/^ ^^^^mm^iii^jjigii^g^ppT^?'^ ■ ' •*»£.-.<. "^■■^^■■■91 iLiA irfr iVf^Mihi'""'^ ■ • ■iim'''' ''^•'"' ''^^1 .^:.- -^t:^^ - T^^^HH ■*' -^i#S?i* '/ •".-■ .' ::."-^' . ^i^'W^PBH Figure a. San Pedro. — Specimen of tlie fossiiiferous sand from the lower San Pedro deposits, San Pedro bluff, north of valley. Olivella intorta is the dominating species. Photograph by R. Arnold. Figure b, San Pedro.— SpecimSn of the fossiiiferous lower San Pedro sandstone from Deadman Island. Photograph by R. Arnold. MemdirsCal Acad. Sci.Vdl. III. [arndld] PiATE mi Figure a. Long Beach.— Bluff at Alamitos Beach, looking east, showing horizontal upper San Pedro (Pleistocene) strata. Photograph by R. Arnold. ••f Figure b. Long Beach.— Typical section of the upper San Pedro (Pleistocene) bluff east of Long Beach. (Lowest visible layer composed of fossil shells). Photograph by R. Arnold. Memdirs Cal Acad. 5ci Vol, in. [ArndldJ Plate XXX. --■'■^^m =::^^ Figure a. San Pedro. — South end of the lowest San Pedro terrace, looking northeast from Crawfish George's toward Timm's Point, showing the contorted Miocene shales overlain by the thin horizontal upper San Pedro (Pleistocene) layer. Photograph by R. Arnold. Figure b. Port Harford. — Railroad cut at Fossil Point, looking south, showing Indian kitchen-midden six feet thick and full of shells overlying the Pleistocene deposit of brecciated shale. Photograph by R. Arnold. Memoirs C^Acad. Sci. Volie. [AhNDLdJ PlATE IXXI. ^^; ^^!r?" y^i^ ^m v^ W^:^ .-'■ .#- > . ' "ii ^ ..; :^'^ S3^| ^^^Bp <)L/ Jm^^^^^H ^^H ■BS-"' .'f?^??5! Figure a. Pismo. — Section of sea-cliff three miles nortlnwest of Pismo, sinowing IVliocene shales on right, overlain unconformably by San Pablo (IVIiddle Neocene) sandstone on left, the whole capped by horizontal Pleistocene deposits of brecciated shale. Photograph by R. Arnold. Hi ^■■1 1; Figure b. Santa Barbara. — Bluff just west of the bath-house, showing alternating hard and soft layers of the lower San Pedro (Pleistocene) sandstone. Photograph by R. Arnold. Memoirs Cal Acad. Sci . Vol. hi. [Arndld] Piaie XXXII. ^ 1 ■m '«K \ ^l y^. ^ Figure a. Santa Barbara.— Portion of bluff west of Rocl»»?•. Figure b. San Diego. — Blutt at La Jolla capped by Pleistocene deposit of gravel and sand. Photograph by F. L. Parl<. Memdirs Cal Acad. Sci. Vol m. [AhnoldJ Plate XXXV. Figure a. San Diego. — Bluff at foot of Twenty-sixth street, looking north, showing the fossiliferous upper San Pedro (Pleistocene) deposits in the lower half of the bluff. The Anomia limatula bed is at the very base of the bluff and forms the reefs at the right of the picture. Photograph by R. Arnold. Figure b. San Diego. — Small section of the sea-cliff at Pacific Beach, showing Pecten expansus and Opalia varicostata in the matrix of the San Diego formation (Pliocene). Photograph by R. Arnold. Memoirs Cal Acad. Sci . Vol. hi. [Arnold] Plaie XXXVl. Figure a. San Diego.— Sea-cliff at Pacific Beach, loolium 142 norvegioum 140 nuUalli 140 panamense 56, 139 proceram IS, 27, .30, 32, 35, 56, 59, 60, 139 (Riugicardium) procerum 139 quadrigeuarium 27, 30, .32, 35, 60 (Traohycardium) quadrigenarium 139 ringeus 139 substriatum 141 (Laivicardium) substriatum 141 Caryophyllia 71, 86 aruoldi 46, 71, 86, 87, 88 californica 46, 71, 87, 88 pedroensis 46, 71, 87, 88 Cerastoderma 74, 140 corbis 74, 140 Cerithiacea 82, 290 Cerithidea 82, 296 califoruica 15, 19, 22, 23, 25, 28, 31, 33, 40, 60, 82, 296, 297 decollatum 296 sac rata 297 CerithiidiB 82, 291 CerithiopsidiB 82, 290 Cerilhiopds asshnilala 290 Cerilhium caU/ornkum 296 filostim 292 (Potamis) sacratum 296 Cerosloma folialum 245 nullalli 245 Chama 74, 130 exogyra 27, 30, 35, 74, 130 lazarus 130 pelluoida 15, 18, 23, 25, 27, .30, 35, 74, 130 sp'moaa yax. ptllucida 130 Chamacea 73, 130 Chamida) 130 Chemnilzia crcbrifilata 276 (jibbosa 279 muricata 270 similis 270 subcuspidata 277 tenuicula lib torquata 271 var. stylina 272 tridenlata 273 var. auranlia 272 Chicoreus 80, 243 leeauus 80, 243 trialatus 80, 243 Chioue 75, 147 brevilineata 149 Chione callosa 147 calif orniensis 149 ducfifraija 60, 75, 147 gvidia 75, 147 neglecta 75, 148 nullalli 149 sitnillwia 32, 56, 60, 75, 148 succincta 33, 55, 56, 60, 75, 148, 149 Chiton amiculalus 342 californicus 342 muscosus 343 regularis 342 sitkensis 342 stelleri 342 (Cryptochilon) stelleri 342 Chitonidio 85, 342 Chlamys 72, 107, 109 hastatus 72, 109 hericeiis 72, 110 var. strategus 72, 110 jordani 72, 111 latiauritus 72, HI var. fucicolus 112 var. fragiUs 72, 112 var. monotimeris 72, 112 opuntia 72, 113 Chlorostoma 84, 324 argyrostroma 324 aureotinctum 28, 40, 84, 324 brunuenm 15, 23, 25, 40, 50, 84, 324 fuuebrale 19, 22, 23, 25, 28, 31, 32, 33, 40, 55, 60, 84, 325 var. subapertum 19, 22, 23, 25, 28, 31, 40, 84, 325 gallina 23, 25, 28, 40, 60, 84, 326 marcidus 328 monterei/ensis 326 montereyi 15, 19, 23, 25, 28, 40, 60, 84, 325, 326, 328 pfeifferi 326 pulligo 328 subapertum 23 (Omphalius) viridulum var. ligulatum 19, 22, 23, 25, 28, 31, 40, 327 viridulus 327 Chorus SO, 247 belcheri 25, 28, 31, 40, 55, 80, 247 Chrysallida 82, 281, 283 communis 283 diegensis 82, 284 Chrysodomus 15, 40, 79, 227, 229 autiqua 227 dirus 229 rectirostris 15, 19, 25, 40, 79, 22S tabulatus 15, 17, 19, 22, 40, 52, 55, 67, 79, 228 Cirripedia 85, 344 Clathurella 78, 210 canfieldii 211 conradiana 15, 19, 22, 28, 40, 52, 78, 210 Clavatula 210 408 CALIFORNIA ACADEMY OF SCIENCES. dementia subdiaphana 144 Clidiophora 73, 124 claviculata 124 punctata 18, 27, 35, 60, 73, 124 Clypeastroida 71, 91 Clypidella 85, 339 bimaculata 19, 22, 28, 31, 40, 60, 85, 339 callomarginata 19, 22, 25, 28, 31, 40, 85, 339, 340 pustulata 339 Cojlenterata 71, 86 Columbella 80, 236 oaliforniaua 19, 22, 238, 239 (Astyris) californiana 40, 238 carinala 240 chrysalloidea 19, 22, 28, 237 (^Esopus) chrysalloidea 40, 60, 237 gausapata 15, 17, 19, 22, 23, 25, 28, 31, 33, 239, 240 var. carinata 15, 17, 19, 22, 23, 25, 28, 31, 32, 33, 239 (Astyris) gausapata 40, 52, 55, 60, 239 var. carinata 40, 52, 55, 60, 240 mercatoria 236 minima 28 (Auachis) minima 48, 237 oldroydi 19 (^sopus) oldroydi 40, 238 solidula 80, 236, 237 var. praecursor 28, 40, 236 tuberosa 19, 22, 23, 25, 28, 31, 239, 240 (Astyris) tuberosa 40, 52, 60, 240 Columbellidas 80, 236 Comliiella ( Amphissa) corrui/ata 241 Conchoccle bisecta 135 disjuncta 135 C'oncholepas antiqualus 312 Couidas 78, 199 Conus 78, 199 californicus 15, 17, 19, 22, 23, 25, 28, 31, 32, 33, 40, 60, 78, 197, 199 marmoreus 199 ravus 199 Cooperella 75, 153 subdiaphana 18, 35, 61, 75, 153 Cooperellidfe 75, 153 Coralliophila 81, 262 ne'ritoidea 262 nux 28, 40, 81, 262 Coralliophilinse 81, 262 Corbula 76, 180 gallica 180 luteola 15, 18, 21, 27, 30, 35, 61, 76, 181 Corbulidai 76, 180 Crassinella 73, 127 branneri 73, 127 Crepidula 83, 307 aculeata 19, 22, 28, 40, 68, S3, 308 adunca 19, 22, 24, 28, 31, 40, 52, 55, 56, 61, 83, 308, 311 cali/ornica 308 Crepidula convexa 308 dorsata 19, 25, 31, 40, 83, 309 excavata 57 explanata 310 grandis 24, 40, 58, 61, 68, 83, 309, 310 navicelloides 19, 22, 24, 25, 28, 31, 40, 52, 83, 310 nummaria 310 onyx 19, 22, 24, 28, 31, 40, 61, 83, 310, 311 var. rvgosa 311 peruviana 307 prajrupta 309 princeps 309 rostriformis 308 rugosa 19, 24, 25, 28, 31, 32, 33, 40, 50, 83, 311 Crucibulum 83, 306 axirkula var. spinosum 306 dumosum 306 rudis 306 spinosum 22, 23, 24, 25, 28, 31, 32, 33, 40, 56, 61, 83, 306 Crustacea 20, 22, 24, 25, 28, 31, 47, 85, 344 Crypla adunca 308 dorsata 309 Cryptochitou 85, 342 stelleri 15, 19, 40, 68, 85, 342 Cryptodon bisectus 135 flexuosus 135, 136 nuttalli 178 Cryptodontidaj 74, 135 Cryptomya 76, 179 califoruica 18, 21, 23, 25, 27, 30, 32, 33, 35, 55, 61, 76, 179, 180 ovalis 180 Cryptonatica 83, 313 clausa 83, 313 Ctenobranchiata 78, 198 Cumingia 76, 167 califoruica 15, 18, 21, 23, 25, 27, 35, 76, 167 mutica 167 similis 167 Cupulifera 92 Cyclas acutilineata 131 Cyclostrematidai 85, 335 Cylichua 77, 192 alba 19, 28, 41, 55, 61, 68, 77, 191, 192 arachis 192 cylindracea 67, 192 Cyprasa 82, 288 argus 288 spadicea 24, 41, 82, 288 Cyprajidai 82, 288 Gypricardia pedroana 155 Cyprina bisecta 135 Cythara 78, 211 branneri 19, 41. 52, 78, 211 Cytherea 142 callosa 145 crassatelloidcs 143 ( Tivela) crassalelloides 143 ( Trigonella) crassatelloidcs 143 ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO. 409 Cytherea erycina 143 gigantea 146 solidissima 143 slullorum 143 Daphnella 210 filosa 223 inter/ossa 213 Decapoda 85, 345 Delphinoidea 84, 320 cancellata 320 coronadoensis 61, 84, 320 Dendropoma lituella 299 DentaliidiB 77, 185 Dentalium 77, 185 elephautinum 185 hexagonum 19, 22, 24, 25, 28, 31, 32, 47, 55, 61, 68, 77, 185 indianorum 19, 22, 25, 47, 77, 186, 187 neohexaijovtim 185, 186 pretiosuin var. indianorum 186 pseudohexagonum 19, 28, 47, 61, 77, 186 semipolitum 24, 25, 28, 47, 77, 187 seniislriatum var. semipolitum 187 Diadematoida 71, 90 Diastoma 19, 41, 52, 82, 296 Dione augustiformis 144 nobilis 145 Diplodonta 74, 133 lupiuus 133 orbella IS, 25, 27, 35, 61, 74, 133, 134 serricata 27, 35, 61, 74, 134 Diplodontidffi 74, 133 Dispolma dumosa 306 Ditremata 78, 196 Docoglossa 84, 317 Dolichotoma 78, 202 carpenteriana 78, 202 cooperi 78, 203 tryouiaua 78, 203 DonacidiB 76, 169 Donax 76, 157, 169, 171 californica 18, 21, 27, 35, 76, 170, 171 californictis 170, 171 flexuosus 170 liBvigata 18, 21, 23, 25, 27, 30, 32, 33, 35, 55, 59, 61, 76, 170, 171 navicula 170 obesus 170 stuUorum 143 trunculus 169 Dosinia 16, 146 eallosa 145 discus 146 ponderosa 59, 61, 146 Dosinluaj 75, 146 Drillia 78, 204, 212 caucellata 19, 31, 41, 61, 78, 204, 205 hemphilli 19, 22, 28, 31, 41, 55, 61, 78, 204, 207 incisa 61, 78, 205 (62 ) Drillia inermis 19, 28, 31, 41, 55, 61, 68, 78, 204, 205, 206 var. penicillata 19, 22, 24, 25, 28, 31, 32, 33, 41, 55, 61, 205 johnsoni 28, 41, 78, 206 merriami 15, 19, 41, 78, 207 moesta 200 montereyensis 19, 41, 78, 207 pallida 207 penicillata 78, 205 perversa 208 pudica 28, 41, 78, 208 renaudi 78, 208 torosa 15, 17, 19, 22, 24, 25, 28, 31, 41, 78, 100, 207, 208, 209 Dunkeria laminata 277 ECHINARACHNlnS 71, 91 excenlriciis 20, 22, 24, 25, 28, 31, 46, 53, 55, 57, 58, 61, 71, 91 EchinometridfB 71, 90 Echinoidea 20, 22, 24, 25, 28, 31, 46, 71, 90 Echiuodermata 71, 90 Echinus piirpurattts 90 Elachista californicum 291 Elasmobranchii 85, 346 Emarginuliufe 85, 337 Eochitonia 85, 342 Epiphragmophora 77, 194 Erato 82, 289 columbella 28, 41, 82, 289 laevis 289 Eucrustacea 85, 344 Euechiuoidea 71, 90 Eulima 81, 268 falcata 19, 41, 81, 268, 269 hastata 19, 28, 41, 55, 61, 81, 268, 269 micaus 19, 22, 25, 28, 31, 41, 55, 61, 81, 268, 269 tortuosa 268 Eulimida) 81, 268 Eupleura 80, 248 caudata 248 muriciformis 19, 24, 28, 41, 61, 67, 80, 248, 249 var. curta 28, 41, 80, 249 var. pleistoceuensis 249 var. unispinosa 248, 249 Evalea 82, 281 cequisculpta 284 elegaus 281 gouldii 82, 282 stearnsii 82, 282 Fasciolariid^ 79, 224 Fissurella 85, 340 aspera 338, 340 crenulata 337 inceqtialis 338 var. pica 338 pica 338 picta 340 volcano 19, 22, 24, 25, 28, 31, 33, 41, 61, 85, 340 June 20, 1903. 410 CALIFORNIA ACADEMY OF SCIENCES. Fissurellidaa 85, 337 Fissurellidcea bimaculata 339 callomarginata 340 Fissurellideinas 85, 337 Fissuridea 85, 337 aspera 19, 22, 24, 25, 28, 31, 41, 85, 338, 339 inajqualis 24, 28, 31, 32, 41, 85, 337, 338 murina 19, 24, 25, 28, 31, 41, 85, 339 Fossaridfe 83, 304 Fossarus 83, 304 costatus 304 (Isapis) feuestrata 304 Frenula Jeffrey si 93 FusiniB 79, 224 Fusus, 79, 224 ambustas 225, 226, 227 barbarensis 15, 17, 19, 24, 25, 28, 41, 79, 224, 225 cancellinus 257 corpulenlus 224 dupelithouarsi 224 Jidicula 209 geniculus 225 kobelli 226 luteopictus 19, 24, 25, 28, 31, 41, 79, 225 nicobaricus 224 oregonensis 286 robustus 19, 24, 25, 28, 41, 52, 79, 219, 224, 225, 226, 227 rugosus 19, 41, 79, 224, 225, 226, 227 acalariformis 252 Gadinia 78, 197 afra 197 radiata 197 (Rowellia) radiala 197 reticulata 41, 78, 197 var. radiata 197 Gadiniidaa 78, 197 Galerus 83, 307 chineusis 307 contorlus 307 mammillaris 19, 22, 25, 28, 41, 52, 83, 307 Gastropoda 15, 17, 19, 22, 23, 25, 27, 31, 33, 39, 77, 188 Gemminae 75, 152 Genota 78, 202 carpenteriana 202 Gibbula optabilis 332 parcipieta 333 Glottidia 71, 94 albida 52, 71, 94 Glycymeris 72, 100 barbarensis 23, 25, 27, 30, 35, 61, 72, 100, 101 estrellana 182 generosa 182 iutermedia 101 septentrioualis 23, 25, 27, 30, 32, 36, 72, 100, 101 Olyphis aspera 338 densiclathrata 339 var. murina 339 (rbjphis ineerjuaUs 338 Gj-mnoglossa 81, 268 Haliotid^ 68, 69, 85, 336 Haliotis 33, 49, 50, 68, 85, 336, 337 cracheroidii 3.3, 336 fulgeus 24, 34, 41, 61, 85, 336, 337 gigantea 336 rufesceus 336 sjilendtns 336 Hamiuea 77, 194 cymbifortnis 194 hydatis 194 virescens 28, 41, 77, 194 Helicidaj 77, 194 Helix 28, 77, 194 cuyana 194 (Epiphragmophora) 41, 195 Hinnites 72, 115 cortezi 115 crassus 115 giganteus 21, 23, 27, 30, 36, 72, 115 poulsoni 115 Hipponyx 83, 311, 312 antiquatus 15, 19, 41, 8.3, 102, 312, 313 cornucopias 311 cranioides 19, 22, 24, 31, 41, 61, 83, 312 mitrula 102, 312 tumens 19, 22, 24, 41, 61, 83, 312, 313 Hydrobiinaa 8.3, 305 Hygrophila 77, 195 IsAPis 83, 304 anomala 304 fenestrata 19, 22, 24, 25, 28, 42, 83, 304 Ischnochitou 85, 342 lougicymoa 342 regularis 28, 42, 85, 342 Ismenia jeffreysi 93 Isopleura 85, 342 Ivara 82, 285 terricula 19, 42, 82, 285 Janira bella 103, 104, 105 denlala 104, 105, 106 excavala 104 Jouanuetiua3 77, 184 Kellia 74, 136, 154 laperousii 15, 18, 21, 36, 61, 74, 136, 137 suborbicularis 18, 21, 36, 68, 74, 137 Kelliellidas 74, 138 Keuuerlia 73, 123 bicarinata 18, 36, 73, 123 Jilosa IS, 36, 7.3, 123, 124 Labiosa 76, 177 (Rit'ta) iindulata 177 Lacuna, 83, 302, 321 carinala 303 oompacta 19, 28, 31, 42, 52, 55, 61, 83, 302, 303 ARNOLD— THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 411 Lacuna pallidula 302 porrecta 19, 22, 24, 25, 28, 31, 42, 83, 303 solidula 19, 28, 42, 61, 83, 303 var. compacta 302 LfBvieardium 74, 140 elatum 74, 141 substrlatum 18, 21, 23, 25, 27, 30, 33, 36, 61, 74, 141 Lamellaria 84, 317 depressa 317 perspicua 317 steaiusii 19, 42, 61, 84, 317 Lamellariidae 84, 317 Laucea 81, 272 aurantia 81, 272 elougatii 272 pentalopha 81, 274 tridentata 81, 273 Laquens 71, 93 californicus 93, 94 var. vancouverensis 93 jeffreysi 15, 46, 51, 52, 53, 71, 93 Lazaria 74, 129 pectunculus 129 subqiiadrata 18, 21, 25, 27, 36, 74, 129 Leda 57, 72, 96 calata 98 fossa 18, 36, 72, 96 hamata 18, 36, 61, 72, 97 miuuta var. prsecursor 18, 21, 36, 72, 97 pernula 96 taphria 15, 17, 18, 21, 23, 25, 27, 31, 32, 36, 61, 72, 98 Ledidre 72, 96 Lepas tintinnabulum 344 Leptonacea 74, 136 Leptonidae 74, 136 Leptonyx hacula 323 sanguinea 323 Leptothyra 84, 322, 323 bacula 19, 31, 42, 52, 84, 323, 324 oarpeuteri 19, 22, 25, 28, 42, 68, 84, 322, 323, 324 paucicostata, 19, 42, 52, 84, 323 sanijuinea 323 sangumeus 323 Leucosyriux 78, 202 pedroana 78, 202, 208 Lima 73, 115 dehiseens 18, 36, 116 (Maatellum) dehiseens 116 hians 115 orientalis 116 squamosa 115 Limidag 73, 115 Limna^idau 77, 195 Lingula albida 94 LingulidjB 71, 94 Linguliuffi 71, 94 Liocardium crueiilatum 141 elatum 141 Liocardium snbstrialum 141 Lioconcha ntwcombiana 143 Liotiidas 84, 320 Lithophaga 73, 121 plumula 73, 121 Lithophagus plumula 31, 36, 121 Littorina 83, 301 litorea 301 palula 301 pedroana 303 plauaxis 13, 19, 22, 28, 42, 83, 301 plena 302 scutulata 19, 22, 24, 25, 28, 31, 32, 42, 55, 61, 83, 301, 302 Littorinidffi 83, 301 Lucapina 85, 337 creuulata 31, 42, 85, 337 Lucapinella callomarginaia 340 LucinidiB 74, 131 Lucina 74, 131 acutiliueata 14, 15, 17, 18, 21, 23, 25, 27, 36, 52, 61, 65, 67, 68, 74, 131, 132 borealis 67, 131 californica 15, 18, 21, 23, 25, 27, 31, 32, 33, 36, 52, 56, 62, 74, 132 jamaicensis 131 nuttalli 18, 21, 23, 25, 27, 31, 32, 33, 36, 62, 74, 132 orbella 134 tenuisculpta 27, 36, 61, 74, 133, 134 teirica 131 Lucinacea 74, 131 Lunatia 84, 315 letoisii 32, 50, 57, 84, 315 Luponia spadicea 288 Lutraria canaliculata 177 capax 17S maxima 178 (Cryptodon) nullalli 178 transmontana 177, 178 undulata 177 venlricosa 175 Lutrariiuas 76, 178 Lutricola alia 160 Lyonsia 73, 125 bracleata 125 californica 15, 18, 21, 23, 25, 27, 36, 73, 125 nilida 125 norvegica 125 Lyonsiidaa 73, 125 Mach^era patula 173 Macoma 52, 75, 160, 161, 169 calcarea 18, 36, 75, 161 edulis 68 expansa 161 indentata 27, 31, 36, 62, 75, 161, 163 iuquinata 15, 18, 23, 25, 27, 31, 33, 36, 48, 56, 62, 68, 75, 162, 163 kelseyi 161, 162, 163, 164 412 CALIFOENIA ACADEMY OF SCIENCES. Macoma nasuta 18, 21, 23, 25, 27, 31, 32, 33, 36, 55, 57, 62, 68, 75, 162, 163, 164, 167 var. kelseyi 27, 31, 36, 62, 75, 164 pedroana 157 seota 18, 21, 23, 25, 27, 31, 32, 33, 36, 62, 68, 75, 163, 164 (Rexithosrus) secia var. edulis 164 tenera 160, 161 tersa 163 yoldiformis 18, 21, 36, 62, 75, 161, 163, 165 Macron 79, 230 kellettii 28, 42, 79, 230 lividus 42, 79, 230 Mactra 76, 164, 174 anatina 177 californica 27, 36, 59, 62, 76, 174, 175, 176 catilliformis 23, 25, 27, 31, 33, 55 (Spisula) catilliformis 36, 62, 176 exoleta 27, 36, 62, 67, 76, 175 falcata 18, 21, 23, 25, 27, 31, 33, 176 (Spisula) falcata 36, 62, 176 hemphilli 27, 36, 76, 175 maxima 178 plauulata 174 var. falcata 176 solida 175 stultomm 174 Mactracea 76, 174 Mactridas 76, 174 Mactrinaa 76, 174 Mcera salmonea 157 Malacostraca 85, 345 Maugilia 55, 78, 210, 211 angulata 10, 22, 25, 31, 42, 52, 55, 62, 78, 212 (Cythara) branneri 211 (Clathurella) couradiaua 210 hooveri 28, 42, 78, 212 interfossa 213 var. pedroana 19, 25, 42, 52, 79, 213 interlirata 19, 31, 42, 79, 213 oldroydi 19, 42, 79, 213, 214, 215 painei 19, 42, 79, 214 sculijturata 15, 42, 79, 214, 215 striosa 28, 31, 42, 62, 79, 215 (Taranis) strongi 215 variegata 212 Mangiliffi 214 Mantellum 73, 115 dehiseens 7.3, 116 Margarita 84, 332 calosloma 333 cidaris 3.34 heliciua 332 optabilis 332, 333 var. knechti 22, 23, 28, 42, 84, 332, 333 var. nodosa 19, 22, 42, 84, 332 parcipicta 84, 333 var. pedroana 19, 22, 24, 28, 31, 42, 84, 333 pupilla 42, 52, 84, 333 Margarita salmonea 333 Marginella 79, 221 globella 221 jewettii 19, 22, 24, 25, 28, 42, 79, 221 (Volvarina) varia 222 MargiuellidiB 79, 221 Megatebennus bimaculatus 339 Megerlia jeffreysi 93 MelampiiiiB 78, 196 Melampus 78, 196 Melampus luteus 196 olivaceus 19, 22, 24, 25, 28, 31, 42, 62, 78, 197 Melauia rufa 274 scalaris 277 Me.rcenaria perlaminosa 146 Meretrix callosa 145 Metis 75, 160 alta 18, 23, 25, 27, 31, 36, 62, 75, 160 Mitra 79, 222 episcopalis 222 maura 22, 24, 25, 28, 42, 79, 222 Mitridas 79, 222 Mitromorpha 79, 223 aspera 223, 224 filosa 19, 42, 79, 223, 224 gracilis 223 intermedia 19, 42, 52, 79, 223 Modelia striata 303 Modiola fornicata 18, 31, 36, 52, 55, 120 pulex 118 recta 18, 23, 27, 31, 36, 62, 120 Modiolus 73, 120 fornicatus 73, 120 rectus 73, 120 Mcerella 75, 156 salmonea 18, 36, 75, 157 Mollusca 72, 75, 76, 77, 78, 79, 80, 81, 82, S3, 84, 85, 95 MoUuscoidea 71, 92 Monia 73, 116 maoroschisma 73, 116 Monoceros 80, 246 brcvidens 247 eugouatum 19, 22, 24, 25, 28, 31, 32, 42, 55, 56 62, 80, 246, 247 var. spiratum 247 lapilloides 28, 42, 80, 246, 247 lugubre 246 punctatum 247 unicarinatum 246 Monodonta (jaUiiia 326. Monotremata 77, 194 Mopalia 85, 343 blainvillei 343 ciliata 28, 42, 85, 343 muscosa 343 Mopaliidn) 85, 343 Motiretia reticulata 197 Murex 80, 243 adustus 243 barbarensis 254 ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 413 Murex belcheri 247 cali/oriiicus 243, 246 festivus 19, 24, 25, 28, 31, 244 (Pteronotus) festivus 43, 244 foliatas 28, 245 (Pterorhytis) foliatas 43, 245 foveolata 255 leeamis 25, 28, 67 (Chicoreus) leeanus 43, 243 monoceros 28, 246 (Cerostoma) monoceros 43 (Pterorhytis) mouoceros 246 multicostaius 251 uuttalli 244 (Pterorhytis) uuttalli 43, 62, 245 nux 262 ptrilus 259 tenuispina 243 trialatus 24, 25, 28, 43, 243 (Chicoreus) trialatus 243 trigonulus 244 Muricida) 80, 243 Muricidea barbarensis 254 californica 243 foveolata 255 paucivaricata 246 [Phyllonotus) paucivaricata 246 perita 259 Mya abrupta 182 cancellatus 179 glycymeris 182 norvegica 183 Myacea 179 Myacidffl 76, 179 Afysia 134 MytUacea 73, 118 Mytilidas 73, 118 Mytilimeria 73, 125 nuttalli 15, 18, 21, 37, 73, 125, 126 Mytilus 73, 118, 126 abbreviatus: 1 18 bifurcatus 119 borealis 118 californicus 50 edulis 18, 23, 25, 27, 33, 36, 49, 68, 73, 118, 119 incurvattts 118 lithophagus 121 minijanensis 118 modiolus 120 noiatus 118 pedroanus 118 pellucidus 118 smaragdiuus 118 subsaxatilis 118 vetustus 118 Myurella simplex 57, 198 Naoella depicta 317 incessa 318 inalabilis 318 Nacella paleacea 319 Narona cooperi 217 Nassa 79, 230 californiana 15, 19, 24, 28, 31, 32, 43, 55, 62, 79, 231, 232 cerritensis 25, 28, 31, 32, 43, 62, 79, 231 cooperi 17, 232, 234 fossata 15, 19, 22, 24, 25, 28, 31, 32, 33, 43, 55, 56, 62, 79, 231, 232 gibbesii 233 insculpta 28, 43, 79, 233 interstriata 234 mendica 15. 17, 19, 22, 24, 25, 28, 31, 32, 43, 52, 55, 57, 62, 80, 233, 234 var. cooperi 15, 19, 22, 24, 25, 28, 31, 32, 33, 43, 56, 62, 80, 232, 234 mutabilis 230 perpinguis 15, 17, 19, 22, 24, 25, 28, 31, 32, 43, 55, 56, 62, 80, 232, 234 pedroana 239 tegula 19, 22, 24, 25, 28, 31, 32, 43, 62, 80, 235, 236 versicolor 236 var. hooveri 28, 43, 80, 233, 236 vibex 235 woodwardi 233 NassidiB 79, 230 Natica 83, 313 algida 315 ampuUaria 315 caurena 313 clausa 15, 17, 19, 43, 52, 57, 65, 68, 313, 314 (Cryptouatica) clausa 313 duplicata 314 kwisii 24, 25, 28, 31, 315 (Lunatia) lewisii 43, 315 mammilla 314 recluiiana 314 reiniana 315 russa 313, 314 Naticidse 83, 313 Neajra 76, 181 ornatissima 181 pectiuata 18, 37, 76, 181 Neptunea tabulata 228 Neverita 83, 314 recluziana 15, 19, 22, 24, 25, 28, 31, 32, 43, 55, 56, 62, 83, 314, 315, 316 var. alt a 55 Nodipecten 72, 108 subnodosus 72, 108 Norrisia 84, 331 uorrisii 24, 43, 62, 84, 323, 331 Nucula 72, 95, 96 cmlata 98 castreusis 15, 17, 18, 21 (Acila) castrensis 37, 95 conradi 95 decisa 95 divaricata 95 414 CALIFORNIA ACADEMY OF SCIENCES. Niicula obliqaa 96 suprastriata 18, 21, 27, 31, 30, 62, 72, !)6 (Nucula) suprastriata 96 tenuis 96 Nuculacea 72, 95 Nuculidas 72, 95 Nuttallia 76, 168 nuttalli 76, 168 Obeliscos variegata 280 Ocinebra 80, 254 barbareusis 19, 22, 43, 52, 80, 254, 259 erinaceus 254 foveolata 28, 43, 80, 255 interfossa 15, 19, 22, 24, 25, 28, 43, 62, 80, 255, 259 keepi 24, 43, 80, 256 lurida 25, 43, 62, 80, 256, 257 var. aspera 19, 22, 24, 25, 28, 31, 43, 52, 55, 80, 257 var. cancelliua 28, 43, 80, 257 var. cerritensis 19, 22, 25, 31, 43, 80, 258 var. nrnnda 19, 43, 80, 258 micheli 25, 43, 80, 259 perita 19, 24, 25, 28, 43, 52, 62, 80, 254, 255, 259 poulsoni 19, 22, 24, 25, 28, 31, 43, 62, 80, 260 Oilostomia 82, 281 {Evalea) aequisculpta 284 (Oscilla) sequiscrilpta 284 (Chrysallida) diegensis 284 (Evalea) elegaus 281 gouldii 19, 22, 43, 52, 55 (Evalea) gouldii 282 (Oscilla) grammatospira 285 jnsculpta 281 interstincta 281 (Evalea) lirata 284 nuciformis 283 var. avellana 19, 43, 52, 55, 62, 283 (Amaura) nuciformis var. avellana 283 plicata 281 (Amaura) pupiformis 283 sandvicensis 281 satura var. pupiformis 283 (Evalea) stearnsii 282 tenuis 22, 23, 28, 43, 55, 62, 82, 281 var. gouldii 282 (Ivara) terricula 285 unideutata 281 CEdalia subdiaphana 153 (Edalina subdiaphana 153 Olivella 79, 219 biplioata 15, 17, 19, 22, 24, 25, 28, 31, 32, 33, 43, 52, 55, 56, 62, 79, 219, 220, 221 bcelica 57, 221 iutorta 15, 19, 22, 24, 25, 28, 31, 32, 33, 44, 55, 56, 62, 79, 220, 221 pedroaua 15, 19, 22, 24, 25, 28, 31, 32, 44, 55, 57, 63, 79, 220, 221 uudatella 219 OlividiB 79, 219 Omphalius 84, 327 /uvescens 327 lirjulatus 327 pfeifferi 326 viridulnm var. ligulatum 84, 327, 339 Ondina 281 sulcata 281 Opalia 81, 266 anomala 58, 63, 81, 266 borealis 28, 44, 81, 266 corouata 266 creuatoides var. iusculpta 44, 81, 267 varicostata 58, 63, 81, 267 Opisthobrauchiata 77, 188 Opsichitouia 85, 343 Oscilla 82, 284 ivquisculpta 82, 284 grammatospira 82, 285 Ostracea 72, 102 Ostrea 57, 72, 102 conchaphila 49 edulis 102 lurida 18, 21, 25, 27, 31, 32, 37, 49, 56, 63, 72, 102 var. expansa 102 var. rufoides 102 maxima 103 veatchi 63 Ostreidai 72, 102 Oudardia butloni 157 Pachydesma crassatelloides 143 Pachypoma 84, 321 caelata 321 gibberosum 321 inaiquale 22, 23, 25, 28, 44, 84, 321 Paludestriua 83, 305 curta 22, 23, 28, 44, 83, 305 piscium 305 stokesi 22, 23, 28, 44, 83, 305 Pandora 73, 123 (Kennerlia) bicarinata 123 bilirala 123 (Kennerlia) filosa 124 punctata 124 Pandoridaj 73, 123 Panomya 77, 183 ampla 15, 37, 65, 77, 183 Panopea 76, 182 estrellann 182 geuerosa 15, 18, 23, 27, 31, 37, 52, 68, 76, 178, 182, 183 var. globosa 182 var. solida 182 norvegica 183 (Mya) norvegica 183 Paracyatlius 71, 88 caltha 88 humiliii 88 ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 415 Paraeyathus pedroensis 46, 71, 88, 89, 90 stearnsi 88, 89 Parapholas penita 184 Patella aculeata 308 anliqualus 312 inscssa 318 instabilis 318 Patelloida depicta 317 Patinopecten 72, 107 caurinus 72, 107 expausus 72, 108 Pecteii 72, 103, 107, 108, 115, 116 iequisulcatus 33, 56, 114 bellus 51, 52, 53, 72, 104, 106 (Pecteu) bellus 103 caurinus 14, 15, 17, 18, 25, 52, 58, 65, 68, 107, 108 (Patinopecten) caurinus 37, 107 circularis 114 deutatus 27, 67, 104, 105 (Pecteu) deutatus 37, 72, 104 deuticulata 27, 31 diegeusis 104, 105, 106 expansus 58, 63, 107, 108 (Patinopecten) expansus 108 floridus 106 (Hinuites) giganteus 115 hastatus 15, 18, 25, 52, 63, 109, 110, 111, 115 (Chlamys) hastatus 37, 109 hemphilli 51, 58, 63, 72, 104, 105 (Pecten) hemphilli 103, 105 hericeus 15, 18, 63, 65, 68, 109, 110, 111 (Chlamys) hericeus 37, 110 var. strategus 18, 37, 110 inca 114 intermedius 108 islaudicus 107, 109 jordani 15, 17, 18, 52 (Chlamys) jordani 37, HI laqueatus 105 latiauritus 18, 21, 23, 25, 27, 31, 32, 33, 37, 63, 111, 112 var. fragilis 27, 31, 37 var. monotimeris 18, 21, 23, 25, 27, 31, .32, 33, 37, 55, 63 (Chlamys) latiauritus 111 var. fragilis 112 var. fucicolus 112 var. monotimeris 112 maximus 103 mesotimeris 111 monotimeris 112 newsomi 27, 31, 113 (Plagioctenium) newsomi 37, 113 nodosus 108 opuntia 52, 53, 63, HI (Chlamys) opuntia 113 propatiilus 107 stearnsii 15, 37, 58, 63, 104, 105, 106 (Pecten) stearnsii 72, 106 subnodosus 23, 27, 108 Pecten (Nodipeoten) subnodosus 37, 108 subventricosus 63, 113 (Plagioctenium) subventricosus 114 tumidtis 114 tunica 111 ventricosus 23, 25, 27, 31, 32, 33, 55, 56, 63, 113, 114 (Plagioctenium) ventricosus 37, 114 yessoinsis 67, 107 Peotinacea 72, 103 Pectinidai 72, 103 Pectunculiuie 72, 100 Pectunculus corbis 140 patulus 131 scptenlrionalis 101 var. subobsoleta 101 Pelecypoda 15, 17, 18, 21, 23, 25, 27, 30, 33, 35, 72, 95 Penitella 77, 184 penita 77, 184 spelcea 184 Periploma 73, 121 alta 122 argentaria 23, 25, 27, 31, 37, 63, 73, 121, 122 excurva 122 iuitquivalvis 121 lenticularis 122 planinscula 122 Periplomidai 73, 121 Petricola 75, 154 arcuata 154 californica 154 carditoides 18, 23, 25, 27, 31, 33, 37, 56, 63, 75, 154, 155, 156 cognata 75, 156 (Petricolaria) cognata 37, 156 cordieri 155 cylindracea 154 denticulata 18, 27, 31, 37, 75, 155, 156 (Petricolaria) deuticulata 155 fjibha 154 (Rupellaria) lamellifera 155 lapicida 154 lithophaga 155 pedroana 155 pholadiformis 155, 156 Petricolaria 75, 155 cognata 156 denticulata 155 Petricolida) 154 Petrophila 78, 197 Phasianella 84, 321 compta 19, 22, 28, 44, 63, 84, 321 fulmoides 321 Phasianellid.-B 321 PholadidiB 156, 183 Pholadidea 77, 184 loscombiana 184 peuita 15, 23, 25, 27, 31, 37, 48, 50, 184 (Penitella) jieuita 184 Pholadiuaj 77, 183 416 CALIFORNIA ACADEMY OF SCIENCES. Pholas concamerata 184 conradi 184 crispata 183 pcnita 184 Phorcus 84, 328 magus 328 puUigo 25, 44, 84, 328 Phyllonolus paucivaricata 246 Physa 78, 196 fontinalis 196 heterostropha 22, 23, 44, 78, 196 Physidic 78, 196 Pisania 79, 227 fortis 24, 28, 44, 56, 63, 79, 227 pusio 227 Pisces 28, 47, 85, 346 Placunanomia alope 116 cepio 116 macroschisma 56, 116 (Monia) machroschisma 116 Plagiocteujum 72, 113 newsomi 72, 113 subventricosus 72, 114 ventricosus 72, 114 PlanorbiiiEB 77, 195 Planorbis 77, 195 corueus 195 tumidus 22, 23, 28, 44, 77, 195 vermicularis 22, 23, 28, 44, 77, 195 Platyodon 76, 179 cancellatus 23, 25, 27, 31, 37, 76, 179 Pleurotoma 77, 199, 228 aurantia 206 babylonia 199 bartschi 15, 19 (Borsouia) bartschi 44, 200 cariuata 216 carpenteriana 24, 25, 28, 32, 55, 56, 63, 203 (Dolichotoma) carpenteriana 44, 202 {Surcula) carpenlerinna 202 cooperi 28 (Dolichotoma) cooperi 44, 203 dam 15, 19 (Borsonia) dalli 44, 201 gibbosa 204 hooveri 19 (Borsouia) hooveri 44, 201 hiermis 205 linearis 210 mitnL'formis 202 montereyensis 206 (Drillia) montereyensis 207 pedroana 19 (Leucosyrinx) pedroana 44, 202 penicillata 205 perversa 15, 19, 22, 24, 28, 31, 44, 56, 77, 200, 216 ponderosa 211 pudica 208 pyrenaica 200 Plenrotoma renaudi 15, 19 (Drillia) renaudi 44 smithi 15, 19 (Spirotropsis) smithi 44, 216 stromboides 211 - tryouiana 28 (Dolichotoma) tryoniana 44, 203 {Surcula) Iryotiiana 203 turricula 209 Pleurotomidm 77, 199, 210 Pododesmus 73, 116 macroschisma 23, 25, 27, 52, 63, 68, 116, 118 (Monia) macroschisma 37, 116 rudis 116 Polyuices 83, 314 (Lunatia) lewisii 315 (Neverita) recUiziana 314 var. alta 315 Polyplacophora 85, 342 Polyphx gracilis 250 Pomaulax 84, 322 undosus 25, 28, 44, 56, 63, 84, 322 Poromyacea 73, 126 Potamis sacratum 296 Priene 82, 286 cancellatus 286 oregonensis 15, 19, 24, 25, 28, 44, 68, 82, 286 Priouodesmaeea 72, 95 Protocardia 74, 142 centifilosa 15, 17, 18, 37, 52, 74, 142 Psammobia 76, 167, 168 edentula 27, 37, 76, 168 (Psammobia) edentula 168 feroensis 167 Psammobiidas 76, 167 Psephis 75, 152 lordi 152 salmonea 18, 21, 37, 52, 76, 152 tautilla 18, 21, 23, 27, 31, 37, 75, 152, 153 Pseudoliva kellettii 230 Ptenoglossa 81, 262 Pterouotus 80, 244 Jeslivus 32, 63, 80, 244 textilis 244 Pteropsidinte 76, 177 Pterorhytis 80, 244 foliatus 80, 245 monoceros 80, 246 nuUalli 80, 245 Plychstylis caffea 327 Pulmonata 77, 194 Puucturella 85, 341 cucuUata 15, 19, 28, 44, 52, 85, 341 galeata 15, 19, 44, 85, 341 uoachiua 341 Purpura 50, 81, 260 caualiculata 50 crispata 24, 25, 28, 44, 48, 63, 68, 80, 227, 261 (Monoceros) lapilloides 247 lapillus 261 ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 417 Purpura persica 260 saxicola 28, +4, 55, 80, 247, 261 PurpurinaB 81, 260 Pyramidella 82, 280 couica var. variegata 28, 44, 82, 280 plicata 280 Pyramidellid* 81, 269 Pyrgisculus 81, 277 lamiuata 81, 277 Pyrgiscus 81, 274 auricoma 81, 274 crebrifilata 81, 276 latifundia 81, 275 subcuspidata 81, 277 tenuicula 81, 275, 276 Pyrgolampros 81, 278 adleri 81, 280 arnoldi 82, 279 gibbosa 81, 279 lowei 81, 278 var. pedroana 81, 279 mioperplicatulus 278 Pyrgostelis 274 Pyrgostylus 272 Kaeta 76, 177 ttndulaia 18, 37, 57, 76, 174, 177 Ranella 82, 287 calif ornica 24, 25, 28, 31, 44, 63, 82, 287 mtiriciformis 248 plicata 248 spiuosa 287 triquetra 248 Hexilhcerus secta Tar. cduli.i 164 Rictaxis 77, 188 punctocalata 77, 188, 189 Rimula cucullata 341 galcata 341 Ringicardium 74, 139 procerum 74, 139 Rissoa 83, 304 acutelirata 28, 44, 55, 83, 305 costulata 304 Rissoidse 83, 304 RowMia 197 radiata 197 Rupellaria 75, 155 lamellifera 23, 37, 75, 155 Sanguinolaria 76, 168 califoriiica 161 nuttalli 27, 31, .37, 68, 168 (Nuttallia) uuttalli 168 sordida 161 SaxicavidiB 76, 182 Saxicava carditoides 154 Saxidomus 75, 151 aratus 18, 23, 25, 27, 31, 33, 37, 48, 55, 63, 75, 151 gracilis 151 nuttallii 151 (63) Scala 81, 262 bellastriata 28, 44, 81, 26.3, 264 {Opalia) boreaUs 266 crebricostata 22, 2.3, 24, 28, 44, 55, 63, 81, 263, 265 hemphilli 28, 44, 81, 263, 264 hindsii 19, 22, 24, 28, 31, 45, 81, 263, 264, 265 indiauorum 15, 19, 22, 24, 25, 28, 31, 45, 81, 263, 264 pretiosa 262 tiucta 19, 22, 24, 25, 28, 31, 32, 45, 55, 63, 81, 263, 264, 265 Scalaria bellaslrhala 263 borealis 266 crebricostata 263 hindsii 264 indianorum 265 var. tinctn 265 stibcorotia/a 264 tincia 265 Scalidaj 81, 262 Scaphaudridas 77, 192 Scaphopoda 19, 22, 24, 25, 28, 31, 47, 77, 185 Schizopyga californiana 231 calif ornica 231 Schizothcerus nuttalli 178 scopali 75 ponderosa 75 Scrobicularia biangulata 160 Scurria mitra 318 Scutella 71, 91 excentrica 91 (Echinarachiiius) exceutricus 91 iuterliueata 16 striatula 91 Scutellidas 71, 91 Sella 82, 290 assimilata 19, 45, 82, 290 Selachii 85, 346 Semele 76, 165 decisa 21, 23, 27, 31, 38, 63, 76, 165, 166 pulchra 27, 31, 38, 63, 76, 166 var. montereyi 18, 38, 76, 166 Semelidie 75, 165 Septifer 73, 119 bifurcatus 18, 38, 119 heberti 119 lampe 73 Serpulorbis 83, 299 arenaria 299 squamigerus 19, 22, 24, 25, 28, 31, 32, 45, 63, 83, 299 (Vermicularia) 299 Sigaretus 84, 316 debilis 31, 45, 84, 316, 317 neritoideus 316 Siliqua 76, 172 calif ornica 173 lucida 18, 21, 27, 31, 38, 63, 76, 172, 173 nuttalli 173 Jane 33, I9O3. 418 CALIFORNIA ACADEMY OF SCIENCES. Siliqua patula 76, 173 var. nuttalli 27, 38, 63, 172, 173 rndiata 172 Silequaria edentula 168 Siphonalia 79, 229 kellettii 25, 28, 31, 45, 63, 68, 79, 229 nodosa 229 Siphonium [DendropOma) lUuella 299 Solariella 84, 334 cidaris 15, 45, 67, 334 oxyhasvi 334 peiamabilis 15, 45, 67, 85, 334, 335 SoliiCurluK cali/orninnus 169 lucida 172 nutlalU 173 rndiata 172 Solen 76, 171 gibbus 169 marginatuB 171 radius 172 rosaceus 18, 21, 23, 25, 27, 38, 63, 76, 171 sicarius 15, 17, 18, 21, 23, 25, 27, 31, 38, 76, 171, 172 Tar. rosaceus 171 Solenacea 76, 171 Solemdie 76, 171, 172 Soleuoconchia 77, 185 Sphairella tumida 134 Sphcenia cnlifornka 180 Spiroglyphus 83, 299 lituella 24, 25, 28, 31, 45, 83, 299 epiroibis 299 Spirotiopsis 79, 216 smithi 79, 216 Spisula 76, 175 catilliformis 76, 176 falcata 76, 174, 176 Standella cnlifornica 174 falcata 176 naiiula 176 Stereosomala 71, 90 Strephona pedroana 221 Streptodouta 81, 262 Streptoueura 78, 198 Strioturbouilla 81, 270 alpiua 270 muricata 81, 270 similis 81, 270 steamsii 81, 271 torqnata 81, 271 var. st.yliiia SI, 272 Strongylocentrotiis 71, 90 franciscauua 20, 46, 71, 90 purpuratus 20, 46, 53, 63, 71, 90 Styliferina 82, 295 tennisculpta 19, 45, 82, 296 Stylommatophora 77, 194 Surcula carpenteriana 202 perversa 200 tryoniana 203 TaeniogloBsa 82, 285 Tagelus 76, 169 californiauus 2.3, 25, 27, 31, 32, 38, 49, 65, 75, 76, 169, 173 Tapes 75, 149, 151 diver sum 150 gracilis 151 laciuiata 27, 31, .38, 150 lineatuvi 150 litterata 149 montaua 145 staminea 18, 21, 23, 25, 27, 28, 31, 32, 33, 38, 48, 56, 63, 68, 75, 150 var. ruderata 149 tenerrima 23, 25, 27, 28, 31, 38, 55, 64, 75, 151 Tapetinaa 75, 149 Taranis 79, 215 morchii 215 strongi 15, 19, 22, 31, 45, 79, 215 Teleodesmacea 73, 127 Tellina 75, 156 al/a 160 bodegensis 18, 21, 23, 25, 27, 31, 32, 33, 38, 64, 68, 158, 159, 165 (Angulus) bodegeusis 158 buttoni 157 {Oudardia) buttoni 157 calcarea 161 donacina 156 emacerata 158 ida? 31, 38, 158, 159 (Augulus) idm 158 inquinala 162 lanceolata 157 lata 161 ligamentinn. 164 meyeri 160 (Angulus) modestus Tar. obtusus 157 nasula 163 obtusa 157 pedroana 157, 161 proxima 161 reticulata 165 rubesceus 27, 38, 159 (Augulus) rubescens 159 (Mosrella) salmouea 157 secta 164 sordidn 161 striata 158 subulosa 161 tenera 161 Telliuacea 75, 156 TellineUa 158 TelliuidiB 75, 156 Terebra 57, 78, 198 nebulosa 198 simplex 15, 17, 19, 22, 24, 25, 28, 31, 32, 64, 198 (Acus) simplex 45, 198 varicgata J 98 Terebratalia 71, 92 ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 419 Terebratalia hemphilli 51, 52, 5,S, 71, 92, 93 obsoleta 92 smithi 15, 46, 71, 92, 93 Terebratulida? 71, 92 Terebridae 78, 198 Thalotia 84, 327 caffea 15, 19, 45, 84, 327 conicus 327 Thuracica 85, 344 Thracia 73, 122 curta 122 pubescens 122 trapezoides 15, 17, 38, 73, 122, 123 Thraciidae 73, 122 Thyasira 74, 135 bisecta 15, 17, 38, 65, 74, 135, 136 (Cryptodou) bisecta 14 flexuosus 135 gouldi 15, 17, 38, 74, 135, 136 Thyatira bisecta 135 Tivola 74, 142 crassatelloides 18, 23, 25, 27, 31, 32, 33, 38, 64, 74, 143, 153 Tornatella 57 fasciata 188 punclocfelatn 188, 189 Tornatina 77, 189 cerealis 19, 22, 28, 45, 64, 77, 189 coarctata 189 culcitella 19, 22, 24, 25, 28, 31, 45, 52, 55, 64, 77, 190 eximia 15, 45, 77, 190 harpa 45, 55, 64, 77, 191 Tornatinidas 77, 189 Toxocidaris franciscnna 90 Toxoglossa 78, 198 Trachycardium 74, 138 quadrigeuarium 74, 139 Tresus 76, 178 maxitnufi 178 nuttalli 23, 25, 27, 31, 38, 64, 68, 76, 178, 180 TriforidiiB 82, 290 Tiiforis 82, 290 adversa 19, 45, 82, 290 perversus 290 Triyonella crassatelloides 143 Trigonia crassatelloides 143 slallorum 143 tantilla 153 Triton 287 (libbosus 28, 286 oregonense 286 (Priene) oreyovensis 286 Tritonidaj 82, 285 Tritonium 82, 285 gibbosus 45, 82, 286 luridum 256 oregonense 286 oregonensis 68 (Priene) oregonensis 286 variegatus 285 Trivia 82, 288 californica 28, 45, 82, 288, 289 qiiadripnnctata 288 solandri 45, 82, 289 Trochidie 84, 324 Trochischus convcxus 331 norrisii 331 Trochus annulatus 329 aureotinctus 324 brunneus 324 cnnaliciilalus 329 coslatus 330 funebralis 325 gaUina 326 (Monodonta) gallina 326 gibberosus 321 incequalis 321 Ugulatus 327 luridus 327 montereyi 326 pulligo 328 pupilhis 333 iDidosus 322 Trophon 65, 80, 249 cerritensis 19, 31, 250 (Boreotrophou) cerritensis 45, 249 clathratus 249 craticulatus 250 disparilis 251, 253 gracilis 15, 19, 52, 251 (Boreotroplion) gracilis 45, 250 mnlticostatus 19, 28, 250, 251, 252 (Boreotrophon) multicostatns 45, 251 orpheuB 68, 252, 253 var. prsecursor 15, 19, 45, 52, 253 pedroana 19, 22, 250, 252 (Boreotrophon) pedroana 45, 251 scalariformis 15, 19, 25, 56, 251, 252 (Boreotrophon) scalariformis 45, 252 Btiiarti 15, 17, 19, 45, 68, 250, 252, 256 (Boreotrophon) stuarti 252 tenuisculptus 15, 253 ' (Boreotrophon) tenuisculptus 45, 253 triaugulatus 19, 254 (Boreotrophon) triangulatns 45, 254 Truncaria corriigala 241 Trygonid* 85, 346 TurbinidiB 84, 321 Turbinolidffi 71, 86 Turbonilla 55, 64, 81, 269, 281 adleri 19, 45 • (Pyrgolampros) adleri 280 arnoldi 19, 45 (Pyrgolampros) arnoldi 279 aspera 291 aurautia 19, 22, 28, 31, 45 (Lancea) aurantia 272 (Pyrgiscus) auricoma 274 crebrifilata 19, 22, 31, 45 (Pyrgiscus) crebritilata 276 (Lancea) ^elongata 272 420 CALIFORNIA ACADEMY OF SCIENCES. Turbonilla gibbosa 19, 46 (Pyrgolampros) gibbosa 279 lamiuata 19, 22, 28, 31, 46, 55 (Pyrgisculus) laminata 277 latifundia 46 (Pyrgiscus) latifundia 275 lowei 19, 22, 28, 31, 46, 279 (Pyrgolampros) lowei 278 var. pedroana 279 mexicana 280 muricata 19, 22, 46 (Strioturbouilla) muricata 270 pentalopha 19, 46 (Lancea) pentalopha 274 plicaiula 269 plicatulus 269 similis 19, 22, 31, 46 (Strioturbouilla) similis 270 stearnsii 22, 23, 28, 31, 46, 270, 271 (Strioturbouilla) stearnsii 271 subcuspidata 19, 22, 28, 31, 46 (Pyrgiscus) subcuspidata 277 tenuicula 19, 22, 28, 31, 46, 276 (Pyrgiscus) tenuicula 275, 276 torquata 19, 46, 272 var. stylina 19, 22, 46, 271 (Strioturbouilla) torquata 271 var. stylina 272 tridentata 19, 22, 31, 46, .52, 273 (Lancea) trideutata 273 typica 269 Turcka (Ptychslylia) cnffra 327 Turckula chlaris 3.34 Turritella 83, 300 apicalis 300 cooperi 15, 17, 19, 22, 24, 25, 28, 31, .32, 46, 54, 55, 56, 57, 64, 83, .300, 301 jewettii 15, 19, 24, 25, 28, 46, 83, 300, 301 sanguinea .300, 301 terebra 300 Turritellid* 83, 300 Urolophus 85, 346 hallori 28, 47, 85, .346 Urosalpinx cnncellinus 257 Veneracea 74, 142 Veuericardia 74, 128 barbarensis 15, 17, 18, 25, 27, 32, ,38, 52, 74, 128 borealis 57 var. vriifricoKa 128 planicostata 128 ventricosa 15, 17, 18, 38, 52, 56, 57, 64, 128 VeueridiB 74, 142, 147 Venerinas 74, 142 Venerupis cordieri 155 Venus 75, 146 bisecla 135 brevilincata 149 californie.a 149 cnllosa 145 Venus corlizi 147 iluctifraga 27, 147 (Chione) fluctifraga 38, 147 gibbosnla 147 gnidia 27, 67, 147 (Chioue) guidia 38, 147 kenncrleyi 146 lamellifera 149, 150, 155 lapicida 154 m axima 1 5 1 neglecta 27, 31, 148 (Chione) neglecta .38, 148 nutlalli 149 perlaminosa 51, 52, 75, 146 rigida 150, 151 rysonia 153 securis 149 simillima 15, 18, 23, 25, 27, 31, 148 (Chione) simillima 38, 148 slnminra 150 succincta 23, 25, 27, 31, 149 (Chione) succincta .38, 149 tantiUus 1.53 verrucosa 146 Vermetid* 83, 299 Vermeliis squamigerun 299 Vermicularia 19, 46, 83, 299 Vertebrata 85, 346 Verticordia 73, 126 cardiiformis 126 novemcostata 18, 38, 73, 126 ornata 126 Verticordiidae 73, 126 Vitrinella 64, 85, 335 anomala 335 williamsoni 19, 28, 46, 85, 335 Vilularia axprra 257 Vola 57 denlala 104 Volvarla alba 192 Volvarina 79, 222 varia 19, 22, 24, 25, 28, 31, 4fi, 64, 79, 222 Volvula 77, 191 acuminator 191 cylindrica 19, 46, 64, 77, 191 YoLDiA 72, 99 amygdala 100 arctica 99 cooperi 27, 38, 55, 64, 72, 99, 100 impressa 99 myalis 99 scissurata 18, 38, 72, 99, 100 ZlRPnasA 77, 183 crispnla 56, 184 gabbii 2.3, 25, 27, 31, .32, 38, 56, 77, 184 Zizyphinun annulnlus 329 canaliculnlus 329 /Jto.sH.v 330 Zygobranchia 85, 336