186 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
distant from the anterior margin, slightly prominent, acute; ligament 
short, very prominent; nymphs very prominent; color whitish, with purple 
zones and rays; epidermis polished, corn-colored, with paler spots and 
rays; cardinal teeth prominent, slender, fragile. Length, inches. 
(Conrad.) 
Type locality, near San Diego, California. 
Range. San Pedro to San Diego, California. In the Pleistocene at 
San Pedro, California. 
Genus HETERODONAX Morch, 1853. 
Shell rounded-triangular, smooth, rather solid; two lateral teeth in 
each valve. (Tryon. S. S. Conch.) 
Type. Tellina bimacnlata Linnaeus, 1758. 
Distribution. Atlantic and Pacific oceans. 
Heterodonax bimaculata Linnaeus, 1758. 
Syst. Nat. ed. 10, p. 677. Conch. Iconica, Tellina; pi. 18, fig. 94. 
Shell sub-cuneiform, compressed, solid, above and within two-spotted 
with red or purple, variously colored with interrupted rays; posterior side 
short, rather square, widely truncated at the end, dorsal margin short, 
ligament conspicuous; anterior side sub-acuminated, dorsal margin slop¬ 
ing, hinge margin with posterior lateral teeth remote, no anterior lateral 
teeth. (Conch. Iconica.) 
This was described as Tellina bimaculata Linnaeus. 
Type in Museum Sowerby. Type locality, West Indies. 
Range. Monterey, California, to Panama. Also Atlantic. 
Genus TAGELUS Gray, 1847. 
Beaks median or sub-posterior; teeth two in each valve, simple, pedun¬ 
culate ; valves without constriction or clavicle, straight; pallial sinus deep, 
reaching to or beyond the beaks; posterior adductor scar rounded; pallial 
sinus with the ventral part partially coalescent with the pallial line. Pal. 
San Pedro. (Arnold.) 
Type. Solen gibbus Spengler. 
Distribution. East and west coasts of North and South America, 
Senegal and Mediterranean. 
Range in time. From the Miocene. 
Tagelus californianus Conrad, 1837. 
Jour. Acad. Nat. Sci. Phila., 7:233; pi. 18, fig. 3.. 
Shell oblong-oval, rather thin, convex; extremities equally rounded; 
basal margin slightly contracted in the middle; beaks central; color white, 
