ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 59? 



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

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

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

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

 Dr. AntiselTs Survey were described by Mr. Conrad, pp. 189-196. He 

 remarks that " the fossils of the Estrella Yalley 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 exemplification 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 

 America 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 subcostata ") were believed to be distinct from those collected 

 by the preceding naturalists. 



Dr. AntiseWs Californian Fossils. 



Page. Plate. Fig. 



190. II. 1,2, Hinnites crassa, Conr. [?=1T. yigantea, Gray.] Sta. Mar- 

 ti, err. typ.] garita. 



I. 1. Pecten Meekii, Conr. San Raphael Hills. 



Pecten deserti, Conr. Blake's Col., p. 15. Corrizo Creek. 



' III. 1. Pecten discus, Conr. Near Sta. Inez. 



191. I. 2. Pecten mag nolia, Conr. [Probably = P. Jeffersonius, Say, Vir- 



ginia.] Near Sta. Inez. 



III. 2. Pecten altiplicatus, Conr. San Raphael Hills. 

 III. 3, 4. Pallium Estrellanum, Conr. [JamraJ] Estrella. 



I. 3. Spondylus Estrellanus, Conr. \?Janira.~\ Estrella. 



192. V. 3, 5. Tapes montana, Conr. San Buenaventura. 

 VII. 1. Tapes Inezensis, Conr. Sta. Inez. 



)} IV. 1, 2. Venus Pajaroana, Conr. Pajaro River. 



;; IV. 3,4. Arcopagia unda, Conr. Shore of Sta. Barbara and Estrella. 



[Closely resembles A. biplicata ; ? Lutricola alta.~\ 

 VII. 4. Cyclas permacra, Conr. Sierra Monica. Resembles C. pan- 



duta, Conr.,=Zwcwa compressa, Lea. 

 VI. 6. Cyclas Estrellana, Conr. Estrella. 



V. 1. Area Obispoana, Com-. San Luis Obispo. 



193. V. 2, 4. Parliy desma Inezana, Conr. [Like P. crassatelloides."] Sta, 



Inez Mts. 



VI. 1, 2. Crassatella collina, Conr. Sta. Inez Mts. 



II. 3. Ostrea subjecta, Conr. "Maybe the young of O. Panzana." 



Sierra Monica. 



,. II. 4. Ostrea Panzana, Conr. Panza, Estrella, and Gaviote Pas. 



H Dosinia alta, Conr. Salinas River. 



VII. 2. Dosinia lonaula, Conr. Salinas River. 



194. VI. 4. Dosinia montana, Conr. Salinas River. 



VI. 5. Dosinia subobliqua, Conr. Salinas River. Alsa it small Venns r 



a Natica, and a Pecten. 



M VIII. 2, 3. Mytilus Inezensis, Conr. Sta. Inez. 

 n V. 6. Lutraria transmontana, Conr. Allied to L. papyria, Conr: 



Los Angeles ; also San Luis. 

 6 81 



