300 University of California Publications in Geology [ v °l. 10 



The Santa Margarita formation northeast of Coalinga is in many 

 localities exceedingly fossiliferous, although the number of species is 

 usually not great. The species of most common occurrence are Ostrea 

 titan Conrad, Ostrea titan corrugata, n. var., Pecten estrellanus Con- 

 rad, Pecten crassicardo Conrad, and Tamiosoma gregaria Conrad. 

 A large number of the forms indicate that the Santa Margarita is 

 closely related to the upper part of the San Pablo to the north. 

 Among others may be mentioned the following species : Dosinia 

 arnoldi Clark, Dosinia merriami occidentalis Clark, Macoma diablo- 

 ensis Clark, Mya dickersoni Clark, Pinna alamedensis Yates, Pinna 

 bicuneata, n. sp., Canccllaria pabloensis Clark, Natica diabloensis 

 Clark, Trophon carisacnsis Anderson. The species obtained from the 

 Santa Margarita north of Coalinga in the collections studied by the 

 writer include the following : 



List of Species from the Santa Margarita North of Coalinga 



Echinodermata *s a 



>ir> K 



Astrodapsis calif ornicus Kew (MS) 



Astrodapsis eoalingaensis Kew (MS) 



Astrodapsis eoalingaensis grandis Kew (MS) 



Astrodapsis scutelliformis Kew (MS) 



Bryozoa 



Several species 



Peleeypoda 



Amiantis communis, n. sp 



Amiantis, sp. (large) 



Cardium quadrigenarium Conrad x x 



Chione semiplicatus, n. sp 



Dosinia arnoldi Clark x 



Dosinia merriami occidentalis Clark x 



Glycimeris, cf. coalingensis Arnold 



Macoma diabloensis Clark 



Macoma indentata Carpenter 



Macoma nasuta (Conrad) x x 



Macoma secta (Conrad) x x 



Metis alta (Conrad) x x 



Mya dickersoni Clark x 



Mya (Platydon) cancellatus Conrad x 



Mya ( Cryptomya ) ovalis Conrad x 



Mytilus kewi Nomland 



Ostrea titan Conrad ? x 



Ostrea titan corrugata, n. var 



Ostrea vespertina Conrad " x 



Panope generosum Gould x x 



Pecten crassicardo Conrad x x 



Pecten estrellanus Conrad x x 



Pecten (Hinnites) giganteus (Gray) x 



