CLASS PELECYPODA 
183 
Family DONACID M. 
Genus DONAX Linnaeus, 1758. 
Shell trigonal, wedge-like, closed; front produced, rounded; posterior 
side short, straight; margins usually crenulated; hinge teeth 2.2; laterals 
1—1 in each valve; ligament external, prominent; pallial sinus deep, hori¬ 
zontal. (Tryon. S. S. Conch.) 
Type. Donax trunculus Linnaeus. 
Distribution. Norway, Baltic, Black Sea, all tropical seas. 
Range in time. Cretaceous, Pleistocene. 
Donax californica Conrad, 1837. 
Jour. Acad. Nat. Sci. Phila., 7:254; pi. 19, fig. 1. 
Shell elongated, somewhat pointed at both extremities; disks with very 
minute radiating lines; color yellowish, obscurely rayed; a brown stripe 
on the anterior and posterior sub-margin; within white and purplish 
brown; margin beautifully crenulated. (Conrad.) 
Type locality, near Santa Barbara, California. 
Range. Santa Barbara, California, to Panama. In the Pleistocene 
at San Pedro, California. 
Donax gouldii Dali, 1919. 
Plate 49, figs. 8, 9. 
Boston Jour. Nat. Hist., 6:394; pi. 15, fig. 9. 
Shell solid, ovate-triangular, ventricose, the surface faintly radiate 
striate, more distinctly so posteriorly, and then as if varnished so as to 
obliterate the furrows; color bluish white, pale fawn color, or rayed with 
these colors, and most specimens have one or more bluish zones; anterior 
dorsal slope rectilinear and nearly at a right angle with the posterior, 
which is a little curved; posterior end heart-shaped, faintly biangular, the 
umbonal angle obtuse and rather ill-defined, but the radiating striae going 
to the posterior basal angle more distinct than elsewhere; anterior end 
rather acutely rounded; a very slight constriction of the basal margin 
posteriorly gives the anterior portion a somewhat pouched appearance. 
Teeth of the hinge well developed. Interior white, inclined to yellow, 
with violet clouds, especially within the pallial impression; a marginal 
blotch along each dorsal edge seems to be pretty constant. Basal margin 
with very decided teeth about the middle, becoming gradually more delicate 
in each direction. Long, diam., % 0 of an i nc h; vertical diam., G / 10 of an 
inch; transverse, % 0 of an inch. (Gould.) 
This is Gould’s D . obesus . 
Type in Boston Soc. Nat. Hist. Type locality, San Diego, California. 
Range. Santa Barbara, California, to Acapulco, Mexico. 
