18 University of California Publications in Geology 



[Vol. 9 



Pelecypoda 



Aeila shumardi Dall 



Cardium lorenzamim Arnold 



Crassatella wasbingtonensis Weaver 



Crenella porterensis Weaver 



Diplodonta, n. sp 



Glycimeris, n. sp. 



Leda impressa Conrad 



Malletia chehalisensis Arnold 



Maerocallista pittsburgensis Arnold 



Panope estrellana Conrad 



Phacoides acutilineatus (Conrad) 



Pitaria, n. sp 



Spisula ramonensis Packard 



Solen curtus Conrad 



Solen, n. sp., aff. parallelus Gabb 



Tellina oregonensis Conrad 



Thraeia condoni Dall 



x 



X X 



X 



X 



X X 



X 



X 



X 



Gastropoda 



Agasoma gravidum (Gabb) x 



Aneillaria fishi Gabb X 



Calyptraea excentriea (Gabb) x 



Fusinus (Priscofusus) hecoxi Arnold x 



Hemifusus washingtoniana Weaver x 



Molopophorus, n. sp 



Molopophorus gabbi Dall X 



Morio, aff. tuberculata Gabb x 



Natica reeluziana Petit x 



Natica oregonensis Conrad x 



Pleurotoma perissolaxoides Arnold 



Scaphander, cf. oregonensis Dall x 



Strepsidura ealiforniea Arnold 



Turris, n. sp. A. 



Turris, n. sp. B 



Turrit ella porterensis Weaver x 



As shown in the above list, sixteen species out of a fauna of twenty- 

 one obtained from the beds at Pittsburg are common to the Agasoma 

 gravidum zone of Contra Costa County. Out of a fauna of eighteen 

 species obtained from the beds of the Lincoln Creek locality eight are 

 common to the Agasoma gravidum zone of Contra Costa County. A 

 noticeable feature of the group of species common to the Agasoma 

 •gravidum zone and these northern localities is that a large proportion 

 of them are fairly highly ornamented types, belonging to genera the 



