ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 



281 



species: e.g.Corbula bicarinata is quoted alive from low water to 17 fm. ; 

 while Anomia lampe, quoted from low-water mark, was found by Major 

 Rich as far north as Monterey in 60 fin. water! 



Of the 157 species described as new, 5 had already appeared under other 

 names, and 15 are believed to be only varieties. Fifteen are named from 

 their doubtful characters or similarity to other forms ; 8 are designated from 

 their habitat or station ; 23 receive names expressive of their small size ; 

 5 are designated according to the number of specimens found; and 6 would 

 probably not have been constituted, had the same shells appeared in the 

 Caribbean waters. 



The following is a comparison of the above collection with that of M. 

 Reigen from Mazatlan, excluding from the latter the land and freshwater 

 shells and the Bryozoa; and bringing down the number of species in Prof. 

 Adams's Catalogue to the standard adopted in the latter. 



Pan. 



Maz. 



Common. 



Bivalves. 

 Univalves. 



Total. 



[synonyms. 

 Old species united : not including 

 New species described. 



Indeterminate species. 

 Minute species. 



136 

 356 



215 

 449 



38=28 per cent. 

 77=21'6 percent. 



492 



664 



115=23-4 percent. 



12 

 139 



104 

 209 





61 

 73 



108 

 298 



? 

 25=34 per cent. 



55. The following are extracted from the British Museum Catalogue of 

 the Veneridce, &c. by M. Deshayes. The minute division of species in this 

 and in his recent articles in the Proc. Zool. Soc. contrasts somewhat strangely 

 with the opposite tendency displayed in his extremely valuable edition of 

 Lamarck's Animaux sans Vertebres, a work which has been employed 

 throughout, but not quoted, simply as not containing original authorities 

 on our present inquiry. 



Dosinia turgida, Rve. = Artemis tenuis, Sow. jun. Central America, 



Sale. 

 Dione brevispinata, Desh.= Cytherea brevispina, Sow. jun. California. 

 Chione callosa, Desh.= Ch. Nuttallii, var. Non Dosinia callosa, Conr. 



California : not Sandw. Is. 

 Venerupis foliacea, Desh. Mazatlan. 



Petricola mirabilis, Desh. [Monterey, Hartweg, teste Sow.'] California. 

 Cyrena Fontainii, T)e$h.=olivacea, Cpr. Non C. Fontainii, D'Orb. 



Mazatlan. 

 Cyrena solida, Phil. Abbild. Conch, p. 78. pi. 1. f. 9. Nicaragua. 

 Cyrena Floridana, Conr. Mazatlan and Florida. 

 The Mazatlan specimens are C. Mexicana,jun. 



56. The collection of which the following is a list, came into my possession 

 exactly as it was received from a sailor, who brought it from a single port on 

 the west coast of North America. The purchaser, judging, from the preva- 

 lence of Mazatlan shells in it, that it came from that place, did not make 

 exact inquiries at the time, and the sailor could not be traced afterwards. 

 Though consisting mainly of shore shells, the collection was so remarkably 

 free from imported specimens, that it derives some value as a geographical 

 authority. The general accordance of the species with what we know of 



Page. 



13 



No. 



25 



76 

 135 



70 



48 



192 

 207 

 253 



8 

 I 



37 



254 



257 



39 

 49 



