ON MOLLTJSCA OP THE WEST COAST OF NORTH AMERICA. 59: 



period the coast-range was entirely under water. The Miocene beds an 

 above 2000 feet in thickness, and abound in fossils generally distinct from 

 those of the eastern strata. There is nothing in Cahfomia answering to the 

 Northern Drift of the countries bordering on the Atlantic. The molluscs of 

 Dr. Antisell's Survey were described by Mr. Conrad, pp. 189-196. He 

 remarks that " the fossils of the EstreUa Valley and Sta. Inez Mountains are 

 quite distinct from those of the Sta. Barbara beds, and bear a strong resem- 

 blance to the existing Pacific fauna. The Miocene period is noted, both in 

 the eastern and western beds, for the extraordinary development of Pecti- 

 nidce, both in number, in size, and in the exempUflcation of typical ideas." 

 It also appears to be peculiarly rich in Arcadce, which are now almost 

 banished from that region, while they flourish further south. The large 

 Amusium caurinum and the delicate Pecten hastatus of the Vancouver district, 

 as well as the remarkable Janira dentata of the Gulf, may be regarded as a 

 legacy to existing seas from the Miocene idea; otherwise the very few 

 Pectinids which occur in collections along the whole West Coast of North 

 Airserica is a fact worthy of note. Mr. Conrad has " no doubt but that the 

 Atlantic and Pacific oceans were connected at the Eocene period;" and the 

 fossils here described afford strong evidence that the connexion existed during 

 the Miocene epoch. All the species here enumerated (except Pecten deserti 

 and " Anomia subeostata ") were believed to be distinct from those collected 

 by the preceding naturalists. 



Dr. Antisell's Oalifornian Fossils. 



Hinnites crassa, Conr. [^ = H. gigantea, Gray.] Sta. Mar- 

 garita. 



Pecten Meekii, Conr. San Raphael Hills. 



Pecten deserti, Conr. Blake's Col., p. 15. Con-izo Creek. 



Pecten discus, Conr. Near Sta. Inez. 



Pecten magnolia, Conr. [Probahly= P. Jeffersonius, Say, Vir- 

 ginia.] Near Sta. Inez. 



Pecten aitipllcatus, Conr. San Raphael Hills. 



Pallium JEsirellanum, Conr. \Janira.'] Estrella. 



Spondylus Estrellanus, Conr. [^Janira.'] Estrella. 



Tapes montana, Conr. San Buenaventui-a. 



Tapes- Inezensis, Conr. Sta. Inez. 



Venus Pajaroana, Conr. Pajaro River. 



Arcmagia unda, Conr. Shore of Sta. Barbara and Estrella. 

 [Closely resembles A. hipUcata ; ? = Lutricola alta.^ 



Cyclas permacra, Conr. Sierra Monica. Resembles C pan- 

 duta, Com:.,= Jjucina compressa, Lea. 



Cyclas Estrellana, Conr. Estrella. 



Area Obispoana, Conr. San Luis Obispo. 



Pachydesma Inezana, Conr. [Like P. crassatelloides.'] Sta. 

 Inez Mts. 



Crassatella collina, Com-. Sta. Inez Mts. 



Ostrea suhjecta, Conr. "May be the young of O. Panzana.^' 

 Sien'a Monica. 



Ostrea Panzana, Conr. Panza, Estrella, and Gaviote Pass. 



Dosinia alta, Conr. Salinas River. 



JDosinialongula, Conr. Salinas River. 



Dosinia montana, Conr. Salinas River. 



Dosinia subobligua, Conr. Salinas River. Also a small Venns, 

 a Natica, and a Pecten. 



Mytilns Inezensis, Conr. Sta. Inez. 



Ltitraria transmontana, Conr. Allied to L. pnpyria, Gonr. 

 Los Angeles ; also San Luis. 

 81 



