110 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Range in time. Jurassic, Pleistocene, San Pedro, and San Diego, 
California. 
Crassinella branneri Arnold, 1903. 
Pal. San Pedro, p. 127; pi. 18, fig. 12. 
Shell small, sub-trigonal, equivalve, inequilateral, convex, thick; umbo 
small, sharp; anterior 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 prominent; 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. Length, 10; height, 8.9; diameter, 5 mm. (Arnold.) 
Type in U. S. N. M. Type locality, the upper San Pedro series of 
San Pedro, California. Fossil. 
Range. San Diego, California to Panama. In the Pleistocene at San 
Pedro and San Diego, California. 
Family CARDITID^E. 
Genus CARDITA (Bruguiere) Lamarck, 1799. 
Shell oblong, radiately ribbed; ligament external; margins toothed; 
hinge-teeth 1.2, and an elongate, posterior tooth; pallial line simple; an¬ 
terior pedal scar close to adductor. (Tryon, Structural and Systematic 
Conch.) 
Type. Chama calyculata Linnaeus. 
Distribution. Universal. 
Range in time. Lower Silurian to Pleistocene. United States, 
Europe, New South Wales, Tasmania. 
SECTION CARDITAMERA Conrad, 1838. 
Cardita subquadrata Carpenter, 1865. 
Suppl. Rep. Brit. Assoc., 1864, p. 642; Ann. Mag. Nat. Hist., (3) 15:178. 
L. testa extus Carditae variegatae jun. simili; pallida, castaneo tincta; 
sub-quadrata, antice truncata, sub-regulariter ventricosa, dorsaliter tumida; 
costis radiantibus circ. xiv.-xvi., tumidis, nodosis, diagonalibus majoribus; 
interstitiis plus minusve insulptis; intus, valva dextra dente cardinali 
triangulari, inter duas fossas sito, haud elongato; dent. lat. a cardine 
separatis, ant. extante, post, obsoleto, calloso; v. sinistrali dent. card. ii. 
angustis, subaequalibus, radiantibus; lat. ant. et post, extantibus; cicatr. 
adduct, sub-rotundatis. Long., .37; lat., ,23; alt., .34. (Carpenter.) 
