sy 
ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 589 
‘Appendix to the Preliminary Geological Report,’ 8vo, Washington, 1855. 
They are divided into, I. “‘ Hocene,” and II. ‘‘ Miocene and Recent Forma- 
tions.” 
Plate. Fig. No. 
nat 1. 
en 9. 
sabietrS) = 8. 
aoe 4. 
ie as 
6. 
AY 1007. 
Ga 8, 
ea. ))9, 
phe. 10, 
e861. 
Cia 8:12. 
a ne Ga 
mes “44 
OS as 
I. Eocene (all from Cafiada de las Uvas*). 
Cardium linteum, Cony., n.s. Allied to C. Nicolleti, Conv. 
Dosinia alta, Cony., n.s. 
Meretrix. Uvasana, Conr., n.s. 
Meretrix Californiana, Conr.,u.s. Allied to IZ Poulsoni, Cony. 
Crassatella Uvasana, Conr., 0.8. 
Crassatella alta, Cony.,n.s. In small fragments, but abundant, 
as at Claiborne, Al. 
Mytilus humerus, Cony., 0.8. 
Cardita planicosta, Lam., = Venericardia ascia, Rogers. First 
discovered 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. 
Natica ? etites, Conr., 1833. 
Natica ? gibbosa, Lea, 1833, or N. semilunata, Lea; also found at 
Claiborne, Al. 
Natica alveata, Conr., n.s. 
Turritelia Uvasana, Conr.,n.s. Alhed to T. obruta, Conr.,=T. 
lineata, Lea, from Claiborne, Al. 
Volutatithes |? Volutilithes| Californiana, Conr., u.s,. Resembles 
V. Sayana, Cony. 
? Busycon Blakei, Conr., n.s. 
Clavatula Californica, Cour., n.s. Allied to C. proruta, Conr., of 
Claiborne Eocene. 
II. Miocene and Recent Formations (from various localities). 
Til. 15. 16. 
ey 9. 17. 
Il. 16. 18, 
» 20. 19, 
> 97. 20, 
> 99) 91. 
» 28 22 
14, 18 
& ait = 
Wh a7, 2A 
29. 25 
Cardium modestum, Conr., n.s. San Diego. [May be Hemicar- 
dium biangulatum, jun. | 
Nucula decisa, Conr., nu.s. Resembles N. divaricata of the Ore- 
gon Miocene. [Closely allied to W. castrensis, &c., but too im- 
perfect to determine.] San Diego. 
Corbula Diegoana, Conr., n.s. San Diego. 
Meretrix uniomeris, Conr., n.s. Monterey Co. 
Meretrix decisa, Conr., n.s. Ocoya Creek. 
Meretrix Tularena, Conr., n.s., [in list, “Tularana”’ in text’. 
From a boulder in Tulare Valley. [Comp. Tapes gracilis, Gld. 
Tellina Diegoana, Conr., n.s., San Diego. 
Tellina congesta, Conr., n.s. [Appears a Heterodonaz, allied to 
Leola Lam.] Abundant at Monterey, Carmello, and San 
lego. 
Tellina Pedroana, Conr.,n.s. [P= ZT. gemma, Gld.] Recent 
formation. San Pedro. 
Arca 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 i situ, fresh forms will be obtained, with which we are already 
familiar in eastern localities.” 
