DESCRIPTIONS OF SUBOENKKA AND SPECIES. 141 



VXIDKXTIFIABLE PFJ TEXS. 



Pecten catii.liformis Coni'iid. 



1856. I'Kten catUliformis Conrad, Pac. R. R. Kept., vol. 5, p. 329, pi. 9, tig. 8.3. 



1888. Frcim catUliformis Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., tor 1887, p. 257 (in 



part). 

 1898. I'i'rtrn ratilliforiiiis Conrad, Dall, TransJ. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 700. 



Oi'iii'niid di-sGriptlon and iiotex. — "Orhiculiir. plano-convex, with radiating 

 .stria' and di.stinct rounded ribs; ears equal. 



"Thi.s large Pecten ha.s such a general resemblance to /*. iiiadmmiun Say, of 

 the Virginia Miocene, that I have no doubt it existed at the same period, or at 

 least after the Eocene. There is none such now living on the coast of California, 

 and none in the Eocene, of this group of large pectens, which occur almost 

 e\erywhere in the Miocene deposits of the Atlantic slope. 



''Localifij. — Ocoya Creek [Kern County]." 



The type of this species was the internal cast of some large Lyrapecten (?) 



probably allied to erassica?'d(/, estrellanuji. or hoicersi. According to Dall the type 



is unknown as the species was described bj- Conrad from drawings made In- Prof. 



W. P. Blake. The figure in the Pacific Railroad Report is so poor and the 



description .so meager that it is probable the species will remain for a long time 



unrecognized. 



Pecten nevadanus Conrad. 



1856. I'eclen nemdanits Conrad, Pac. R. R. Rept., vol. 5, p. 329, pi. 8, tig. 77. 



1888. J'crleii neiadctmis Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 258 (in part). 



1898. Perlrn nemdanu^ Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 700. 



(Jfig'inal descrij}tio/> and notes. — '"Ovate, flat or slightly concave; ribs 17, large, 

 flattened on the back; interstices strongh' wrinkled trausverselj'. 



"This shell is so nearly allied to JS^. (should be P.) Ilnmjdirei/till of Maryland 

 that, taken in connection with P. catltlifonnix^ * * * it may be regarded as a 

 Miocene species. The strata in whicli they occur may safely be referred to that 

 period. 



^'Locality. — Ocoj'a Creek [Kern County]." 



This .species, like the last, was, according to Dall, described by Conrad from 

 one of Professor Blake's drawings of an external mold. The figure and description 

 in the Pacific Railroad Report appears to fit P. hmcerKi ciuite closely. The size 

 of the shell, number and shape of ril)s, and the characteristically sculptured by.ssal 

 area are similar in the two species, but the writer has hesitated to place the 

 latter in the synonymy- of /'. nevadanai<, owing to the uncertainty of usiug ao 

 few characteristics in a definite specific determination of such importance. 



Pecten pyxidatus Carpenter. 



1863. Pecten pi/.rldatiis Carpenter, Hrit. Assn. Rept., 1863, p. 667. 



1898. Pecten pyxiddtiix Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 711. 



This species is listed by Carpenter as having been collected by Captain Stone 

 at Guaymas, Gulf of California. According to Doctor Dall this is probabl}' a 

 Chinese species. 



