30 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH Srr. 
Near the middle of this zone a fossiliferous sandstone 
(bed i) has yielded the following species: 
Arca trilineata CoNRAD Saxidomus aratus GOULD 
Metis (Lutricola) alia CoNRAD Glycimeris generosa GOULD 
Mactra (Spisula) catilli- Diplodonta harfordi ANDERSON 
formis CONRAD Tapes stanleyi GABB 
Pectunculus  septentrion- Mytilus mathewsoni GABE 
alis Mupp. Macoma inquinata (?) DESH. 
Pecten owent ARNOLD Nassa californica ConRaAD 
Pecten estrellanus CONRAD Natica lewisi GouLp 
Pecten crassicardo CONRAD Trochita costellata (?) CoNRAD 
Ostrea titan (?) Conrad Scutella gibbsi REMOND 
In this horizon Pectunculus often occurs in great numbers, 
forming the dominant species. More than any other species 
it is persistent throughout the Coalinga field and is a survivor 
from the preceding series, in which it occurs in limited 
numbers. 
The same fauna is found near the bottom of the Etchegoin 
sands along the tributaries of the Jacalitos creek and the 
streams farther east. It is everywhere characterized by the 
great abundance of Pectunculus and by Pecten owent, Scutella, 
Saxidomus, and Tapes, by many other modern forms and by 
some living ones. Higher in the series the number and variety 
of Pecten species increase, and others which are abundant in 
the lower beds almost or quite disappear. 
On the Zapato Chino creek and eastward a fossiliferous 
bed 1000 feet or more above the base of the series contains 
the following species : 
Arca trilineata CONRAD Balanus sp. 
Saxidomus aratus GOULD Neverita recluziana DESH. 
Pecten coalingaénsis Ar- Nassa californica CoNRAD 
NOLD Terebratella sp. 
Pecten wattsi ARNOLD Clypeaster (Scutella) brewer- 
Pecten etchegoint ANDERSON ianus REMOND 
Chama sp. Clypeaster (Scutella) gibbsi 
Ostrea sp. REMOND 
Tellina sp. Sharks’ teeth, etc. 
A comparison of these lists with the lists of the Pliocene 
occurring at Kirker’s Pass, published by Whitney’ and others, 
1 Geol. Surv. Calif. Geol. v. 1, p. 32. 
