ARNOLD— THE PALEONTOLOGY AND STKATIGUAl'llY OF SAN I'KDltO. 127 



This little shell is one of the unique sipecies of this f;uiii;i. Specitnens ideiiti- 

 tieil by Dr. Dull. 



One specimen from lower San IVdro series of Deuclman Isliuul, whieii is 

 ligured, and is now in the collection of Delos Aniulil. 



Livinij. — Santa Barbara; Samarani^, China; South America (Carpenter): 

 Sau Pedro (Raymond). 



Pleistocene. — San Pedro (Arnold). 



nr.icr T]-:Li':()i)i-:sM.\ri-:\. 



Superfamily ASTARTACEA. 



Family XVIll. ASTAUTlD/l':. 



Genus Astarte Sowerby. 



Shell suborbicular, compressed, thick, smooth, or concentrically furrowed; kmiile com- 

 pressed; ligament external; epidermis dark; hinge-teeth two in each valve, tlie anterior tooth of the 

 right valve large and thick ; anterior pedal scar distinct ; |)allial line simple. 



Asiarte semi»ulcata Leach is a characteristic species. 



Subgenus Crassinella Bayle. 

 Shell obliquely lengthened, subquadrangular. 

 Astarte obliqua Desh. is a characteristic species. 



53. Astarte (Crassinella) branneri, sp. uov. 



Plate XVIII, Fig. 12. 



Shell smalls subtrigonal, ecjuivalve, inequilateral, convex, thick; umbo small, sharp; ante- 

 rior dorsal margin straight to anterior extremity, where it meets the arcuate ventral margin in an 

 angle ; posterior dorsal margin evenly arcuate, sloping down to rounded, posterior extremity ; surface 

 sculptured with numerous angular, concentric undulations or ridges ; lunule long, narrow, extending 

 to anterior extremity, and circumscribed by a narrow, angular ridge ; ligament external, not promi- 

 nent ; two prominent cardinal teeth in right valve; one in left; no laterals; pallial line entire, running 

 from the middle of adductor scars; adductor scars subequal, small. 



Dimensions. — Long. 10 mm.; alt. 8.9 mm.; diam. 5 mm. 



This species somewhat resembles Astarte compacta Cpr., but has a longer 

 lunule, liner concentric ridges, and is more bilatei'ally symmetrical. Specimens 

 pronounced a new species by Dr. Dull. Named in honor of Dr. John C. Branner, 

 Professor of Geology, Leland Stanford Junior University. 



Rare in the upper San Pedro series of San Pedro and Los Cerritos. The 

 specimen figured is the type, which is from the upper San Pedro series at Los 



