ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 589 



'Appendix to the Preliminary Geological Report,' 8vo, "Washinnrton, 1855. 

 They are divided into, 1. " Eocene," and II. " Miocene and Recent Forma- 

 tions." 



I. Eocene (all from Canada de las Uvas *). 



Cardinm linfcum, Conr., n.s. Allied to C. NicoUeti, Cour. 



Jtiisiiiiii a/ffi, Conr., n.s. 



Meretnx Urnsiiiui, Conr., n.s. 



Mt-retiix Cnlit'oniittiia, Conr., n.s. Allied to M. Poulsoni, Conr. 



Cra^xafcHa Vitt<aim, Conr., n.s. 



Cra^snlrlffi (il'n, Conr., n.s. In small fragments, but abundant, 

 a-i lit Claiborne. Al. 



Mjiiihis /iiiiticrin, Conr., n.s. 



Civditn planic'Ktn, Lam., = Venerirardia ascta, Rogers. First 

 disnnvereil in .Maryland in 1829, by Conr. ; occurs abundantly 

 in Md., Va., AL, and i« quite as characteristic of the Ameri- 

 can as of tlip European Eocene period. 



Kt'ticd rofifts. Conr., 18-"{3. 



N(('irii'tiiihJ,osii, htia., l6S'S, or N. seniilunata, Lea; also found at 

 Claibornt', Al. 



Xiifira nlrciifii, ( 'onr., n.s. 



l^Kfritdid l'.(i<an(i. Conr., n. s. Allied to T. ohruta, Conr., = 7'. 

 Uncatd, L<'a. from Claiborne, Al. 



Volutatithe-i \^'rl'iili(tilit/ies] Californiana, Com., n.s. Resembles 

 r. Say ana, Conr. 



?Biisi/ri»i li'alci, Conr., n.s. 



Clavdtiihi Va!i ornica, Conr., n.s. Allied to C. prontta, Conr., of 

 Claiborne Eocene. 



II. Miocene awl Recent Formations (from various localities). 



in. 15. 10. Cardium mo Minn, Conr., n.s. San Diego. [May be Ilemicar- 

 iliiiin hiatKjuhtum, jun.] 

 „ 19. 17. Nucitlu (ii'cisa, Conr., n.s. Resembles K. dtvaricata of the Ore- 

 gon Miocene. [Closely allied to N. castreum, Sec, but too im- 

 perfect to determine.] San Diego. 

 111. 16. 18. Corbula Dii-i/oaiia, Conr., U.S. San Diego. 



Merdrix laiiotneris, Conr., n.s. Morterey Co. 

 3Ieretrix dirisn, Conr., n.s. Ocoya Creek. 



Mvretrix Tula rtia, Conr., n.s., [in list, "Tiihrann^^ in text]. 

 Erom ft bou'.uer in Tulare Valley. [Comp. Tapes t/racilis, (Ud-I 

 Trlfimt l)i>f/i>(i)in, Conr., n.s., San Diego. 



TvUiiia niHj/c-tfa. Conr., n.s. [Appeitrs a TIeterodonax, allied to 

 bimaeulata, Lam.] Abundant at Monterey, Carmello, and San 

 Diego. 

 Telfina Pedroana, Conr., n.s. [?= T. gemma, Gld.] Recent 

 f<irmation. San Pedro. 

 ,, 29. 25. Arc'i mlrrodimtn, Conr., n.s. Resembles A. arata, Say, of the 

 Maryland Miocene. Miocene, ? Tulare Valley. 



• The existence of Eocene strata on the Pacific slope is ascertained by a single boulder 

 of very hard sandstone, wliich, tliouj;h very small, furnished fifteen species. Of tliese, 

 three correspond with forms from Claiborne, Alabama ; and the " finger-post of the 

 Eocene " appears in its usual abundance. Mr. Conrad characterizes the specimens as 

 " beaut ifulU' perfect ;" wliieli would not have been supposed from his descripticns and 

 figures. They " seem to indicate a connexion of tlie Atlantic and Pacific Oceans during 

 the Eocene period ;" and tl'.e author ex])ects tiiat " wlien the rock sliall have been disco- 

 vered and invi'stifrate.l in situ, fresh forma will be obtained, with which we : i ah'cady 

 fawihur iu ea;!U.'ru localities." 



76 



