ON MOLLTJSCA OP THE WEST COAST OF NORTH AMERICA. 589 



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

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

 tions." 



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



Plate. Fig. No. 



II. I. 1. Cardium linteum, Conr., n.s. Allied to C. Nicolkti, Conr. 



2. 2. Dosinia alta, Conr., n.s. 



3. 3. Meretrix Ucasana, Conr., n.s. 



4. 4. Meretrix Californiana, Conr., n.s. Allied to M. Poulsoni, Conr. 



5. 5. Crassatella Ucasana, Conr., n.s. 



6. Crassatdla ol'ft, Conr., n.s. In small fragments, but abundant, 

 as at Claiborne, Al. 



10. 7. Mi/iilus humeni->, Conr., n.s. 



6. 8. Cardita planic'ntit, Lam., = Venericardia ascia, Rogers. First 

 discoA-ered in Maryland in 1829, by Conr. ; occurs abundantly 

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

 can as of the European Eocene period. 



7. 9. Natica?cetites, Conr., 1833. 



7. 10. Natica?gibbosa, Lea, 1833, or N. semilunata, Lea; also found ft 

 Claiborne, Al. 



8. 11. Natica alveata, Conr., n.s. 



;; 12. 12. Turritelia Ucasana, Conr., n. s. Allied to T. obnrfa, CoBT.,= 7'. 

 lineata, Lea, from Claiborne, Al. 



n 9. 13. Volutatithes [? Volutilithes] Californiana, Conr., n.s. Resembles 

 V. Say ana, Conr. 



13. 14. ? Busy can H?akei, Conr., n.s. 



11. 15. Clavatula Cali^ornica, Conr., n.s. Allied to C. pronda, Conr., of 

 Claiborne Eocene. 



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



III. 15. 16. Cardium mo'lestum, Conr., n.s. San Diego. [May be Hemicar- 



dimn bianyidatum, jun.] 



19. 17. Nucida decisa, Conr., n.s. Resembles N. divaricata of the Ore- 

 gon Miocene. [Closely allied to N. castrensis, &c., but too im- 

 perfect to determine.] San Diego. 



III. 16. 18. Corbida Diegoana, Conr., n.s. San Diego. 

 20. 19. Meretrix umomeris, Conr., n.s. Monterey Co. 

 27. 20. Meretrix decisa, Conr., n.s. Ocoya Creek. 



22. 21. Meretrix Tularena, Conr., n.s., [in list, "Tularana" in text]. 

 From a boulder in Tulare Valley. [Comp. Tapes gracilis, Gld.] 

 28. 22. Tettina Diegoana, Conr., n.s., San Diego. 



14 18 I I Tellina congesta. Conr., n.s. [Appears a Heterodonax, allied to 

 &' 21 1 ^' ) bimacidata, Lam.] Abundant at Monterey, Carmellb, and San 



( Diego. 

 17. 24. Tellina Pedroana, Conr., n.s. [?= T. gemma, Gld.] Recent 



formation. San Pedro. 



29. 25. Area microdonta, 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, which, though very small, furnished fifteen species. Of these, 

 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 

 " beautifully perfect ;" which would not have been supposed from his descriptions and 

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

 the Eocene period ;" and the author expects that " when the rock shall have been disco- 

 vered and investigated in situ, fresh forms will be obtained, with which we are already 

 familiar in eastern localities." 



75 



