i8o 



CALIFORNIA ACADEMY OF SCIENCES [Proc. 30 Ser. 



Area trilineata Conrad 

 Saxidomus aratus Gould 

 Pecten coalinga'ensis Arnold 

 Pecten wattsi Arnold 

 Pecten etchegoini n. sp. 

 Chania sp. 

 Ostrea sp. 

 Tellina sp. 

 Ballanus sp. 



Neverita recluziana Desh. 

 Nassa californica Conrad 

 Terebratella sp. 

 Clype aster {Scut ell a) brcweriana 



Remond 

 Scutella gibbsi Remond 

 Astrodapsis tumidus Remond 

 Sharks' teeth, etc. 



Southward on the Jacalitos Creek similar beds near the 

 base of the Etchegoin series contains the following species : 



*Mactra {Mulinia) densata Conrad Pecten crassicardo Conrad 



*Mactra {Spisuta) falcata Gould 

 * Metis {Lutricola) alia Conrad 



Macoma nasuta Cpr. 



Pectunculus septenti-ionalis Midd. 



Saxidomus aratus Gould 



*Hinnites sp. 



* Trophon ponder o sum Gabb 



* Chrysodomis sp. 

 Nassa sp. 

 Natica sp. 



West of Coalinga where the Etchegoin Beds are well 

 exposed and fossiliferous, they contain: 



Mactra {Spisuta) falcata Gould 

 Metis {Lutricola) alta Conrad 

 Saxidomus aratus Gould 

 Tapes staleyi Gabb 

 Pecten oweni Arnold 

 Area trilineata Conrad 

 Pectunculus septentrionalis Midd. 

 Cardimn meekianunt Gabb 



Diplodonta harfordi n. sp. 

 Macoma secta Conrad 

 Pseudocardium sp. 

 Nassa californica Conrad 

 Neverita recluziana Desh. 

 Pleurotoma {Surcula) sp. 

 Scutella gibbsi Remond, etc. 



A comparison of these lists with the lists published by 

 Whitney^ and others for the Pliocene occurring at Kirker's 

 Pass, Contra Costa County, makes it evident that faunally 

 they are of the same group of strata. Furthermore a few 

 days spent by the writer in studying and collecting from the 

 beds occurring on the east shore of San Pablo Bay, Contra 

 Costa County, led to the conclusion that the two thousand or 

 more feet of Pliocene strata occurring there on the southern 

 side of the syncline is the equivalent of the Etchegoin Sands 

 and represents only the basal portion of the Etchegoin Beds 

 in their full development. The same fauna can be recog- 

 nized also a little to the north of Walnut Creek Station on 

 the railroad running to San Ramon. The lowest faunal 



Geol. Surv. Calif. Geol. v. i, p. 32. 



