CLASS PELECYPODA 
163 
Petricola carditoides Conrad, 1837. 
Plate 34, figs. 6a, 6b. 
Jour. Acad. Nat. Sci. Phila., 7:255; pi. 20, fig. 8. 
Shell oblong-oval; disks with minute radiating lines; ligament margin 
straight, parallel with the basal margin; posterior extremity direct; car¬ 
dinal teeth prominent. Length, V /2 inch. (Conrad.) 
Type in Phila. Acad. Nat. Sci. Type locality, near Santa Barbara, 
California. 
Range. Vancouver Island to Lower California. 
Petricola denticulata Sowerby, 1834. 
Proc. Zool. Soc., p. 46. Conch. Iconxca, 19; pi. 11, figs. 9 a, b. 
Shell Pholas-shaped, elongated, anteriorly gaping, acuminated, sloped 
upward and downward at the margins, rayed with depressed crenated 
ribs; posteriorly radiately striated, rather acuminated; chestnut within, at 
the ends and near the ventral margin. Long. 1.1; lat. 0.6; alt. 0.6 poll. 
(Conch. Iconica.) 
Type locality, Payta, Peru. 
Range. California to Peru. 
Family COOPERELLID7E. 
Genus COOPERELLA Carpenter, 1864. 
Cartilage subinternal, the ligament contiguous to it, the cardinal teeth 
simple or one of them bifid. (Tryon. S. S. Conch.) 
Type. CEdalia subdiaphana Carpenter, 1864. 
Distribution. West coast of North America from Queen Charlotte 
Islands, British Columbia, to Gulf of California. 
Cooperella subdiaphana Carpenter, 1864. 
Jour, de Conch., 12:134, 1865. Brit. Assoc. Rcpt., 1864, p. 639. 
Shell small, subquadrangular, subequilateral, convex, very thin and 
fragile; posterior extremity evenly rounded; anterior extremity rounded 
near the base; surface smooth except for incremental lines; beaks slightly 
raised, sharp, prominent; two narrow, tall, sharp, bifid teeth in left valve, 
three in right; pallial sinus very large. Length, 12; height, 9; diameter, 
6 mm. (Arnold.) 
Type locality, San Diego, California. 
Range. Queen Charlotte Islands, British Columbia, to the Gulf of 
California. 
Family TELLINID7E. 
Genus TELLINA (L.) Lamarck, 1799. 
Shell slightly inequivalve, compressed, rounded in front, angular and 
slightly folded posteriorly, umbones, subcentral; teeth 2.2, laterals 1.1, 
