248 



SCIENCE. 



[N. S. Vol. XII. No. 294. 



yielded other interesting forms — many ex- 

 amples of a new species of Lima {L. Ham- 

 lini Dall) of unusual size and of quite dis- 

 tinct characteristics, as well as two of the 

 three species of 'Plagiostoma,' described and 

 figured by the late Dr. John B. Trask in 

 the Proc. California Acad. Sciences in 1856. 

 They were assigned by him to 'the Cre- 

 taceous rocks of Los Angeles ' County. 

 These are listed (? as one and the same 

 species) under the head of ' Tertiary and 

 Quaternary MoUusca,' in Dr. J. G. Coop- 

 er's ' Catalogue of Californian Fossils,' * as 

 Peden Pedroanus Trask, Mioc. — 'San Pedro,' 

 with the remark, 'may be an Aucella and 

 Cretaceous.' 



Dall t refers to Trask's species ' P. Pedro- 

 anus + P. annulatus ' and ' P. truncata ' in 

 his comments on the Pectens of the West 

 Coast in the ' Tertiary Fauna of Florida,' 

 qualifiedly referring them to the Miocene. 

 Dr. Cooper in his prefatory remarks to the 

 Catalogue above quoted, says, " It must be 

 remarked that the exact geological position 

 of many fossils in the Tertiary and Creta- 

 ceous strata is still unsettled, there not be- 

 ing such distinct divisions between them 

 in California as in some other countries." 



The Hippuritid 86 which Woodward placed 

 in his Section B, Family VIII. of the Con- 

 chifera, includes the genera, Hippurites and 

 Badiolites of Lamarck as well as other more 

 or less closely related groups, in the Order 

 Eudistes of Lamarck. As these forms are 

 but little known, it may be well to quote 

 Woodward's description of Radiolites, which 

 is based on examples from the chalk beds of 

 Europe, of which he has given figures in his 

 Manual :|. "Shell inversely conical, biconic, 

 or cylindrical; valves dissimilar in structure; 

 internal margins smooth or finely striated, 



*Seventb Ann. Eep. State Mineralogist o£ Cal., 

 1887-88, pp. 221-308. 



t Trans. Wagner Free Inst. Part IV. , Vol. III. , p. 

 705, April, 1898. 



t Recent and Fossil Shells. Ed., 1880, pp. 446-7. 



simple, continuous ; ligamental inflection 

 very narrow, dividing the deep and rugose 

 cartilage pits ; loiver valve with a thick outer 

 layer often foliaceous ; its cavity deep and 

 straight, with two dental sockets and lateral 

 muscular impressions ; upper valve, flat or 

 conical with a central umbo ; outer layer 

 thin radiated ; umbonal cavity inclined to- 

 wards the ligament ; teeth angular, striated, 

 supporting curved and subequal muscular 

 processes." 



The examples from the tunnel clays con- 

 sist of the remains of four individuals, being 

 portions of the lower valves of two, and the 

 nearly perfect upper valve of a third. The 

 fourth, also an upper valve, is in still better 

 condition ; all are bedded in the clay, but 

 are too fragile to admit of separation from 

 the matrix. The upper valve is discoidal 

 in shape and moderately convex, the umbo 

 central ; the surface in the third example 

 somewhat rugose, and exhibiting concentric 

 growth-ridges and radiating sculpture ; its 

 diameter is about 47 mm. , or an inch and 

 three quarters. In the fourth (upper valve) 

 the concentric sculpture is absent and the 

 radiating feature more conspicuous ; this 

 consists of closely set thread-like ridges, 

 which extend from the umbo to the extreme 

 periphery of the valve, projecting somewhat 

 beyond, forming a pectinated edge or mar- 

 gin, as seen in certain finely sculptured 

 Limpets and Siphonarias. The diameter 

 of this last is slightly in excess of the other, 

 being 49 mm. These upper valves were 

 found at points so distant from the lower 

 valves, as to warrant the conclusion that 

 they were never connected, but are parts of 

 separate individuals. 



But little is left of the lower valves; 

 their concavity is shown by the casts in the 

 clay. Portions of the curious foliaceous 

 lamellse remain intact, so that their char- 

 acter and relation to the outer surface of 

 said valve is indicated. 



The umbos are central or nearly so, in 



