1922] Trash: The Briones Formation of Middle California 141 



The presence of the following forms, which are quite common in 

 the Briones formation, and whose range is either limited to the Briones 

 formation itself, or to the San Pablo group, shows the close faunal 

 relationship between this sandstone and the Briones formation in 

 general. 



Pecten raymondi brionianus, n. var. Fieus stanfordensis Arnold 



Dosinia merriami Clark Natica kirkensis Clark 



Macoina andersoni Clark» Natica pabloensis Clark 



Nassa wkitneyi, n. sp.io Koilopleura sinuata (Gabb) 



Hence, due to this close faunal similarity between this lower sand- 

 stone member and the Briones formation in general, and to the faunal 

 distinctness between it and the Monterey group, it seems that this 

 lower sandstone should be regarded as a part of the Briones formation. 



COMPLETE LIST OF KNOWN SPECIES FROM THE BRIONES 

 FORMATION WITH THEIR GEOLOGIC RANGE 



ECHINODERMATA 



Astrodapsis brewerianus (Remond) 



Astrodapsis brewerianus diabloensis Kew 



Ophiurites (Ophiuroglyphus? ), sp 



Bryozoa 



One species 



Arthropoda 



Balanus, sp. a 



Balanus, sp. b 



Cancer?, sp 



Pelecypoda 



Antigona willisi, n. sp 



Area trilineata Conrad 



Cardium corbis (Martyn), n. var.? 



Cardium quadrigenarium Conrad 



Chione panzana Anderson and Martin 



Diplodonta harfordi Anderson 



Diplodonta parillis (Conrad) 



Diplodonta, sp 



Dosinia arnoldi Clark 



Dosinia merriami Clark 



Dosinia merriami occidentalis Clark 



Leda furlongi, n, sp 



Leda cf. taphria Dall 



a Hacoma andersoni Clark as yet has not been found in the Briones in other 

 regions, but it is fairly common in the Upper San Pablo (Santa Margarita). 

 io Nassa whitneyi, n. sp., may possibly occur in the Monterey. 



