CLASS PELECYPODA 
143 
Cardium californiense Deshayes, 1841. 
Plate 2, fig. 3. 
Guerin Mag. de Zool., Moll., pi. 47. 
Shell small, thin, ventricose, equilateral, subcircular, or a little trans¬ 
versely oval, yellowish white, with a thin, closely adhering, fawn-colored 
epidermis; posterior umbonal slope a little angular, and posterior tip a 
little truncated; beaks prominent, acute, incurved or slightly antrorse; 
surface sculptured with upward of forty radiating ribs having the pre¬ 
senting surface flattened, which, however, at the later stages of growth, 
and especially at the anterior end, are raised into delicate, arched, obtuse, 
crowded, somewhat imbricating, concentric ridges, only seen on careful 
examination; the grooves are also barred by delicate transverse folds; 
the ribs are not wanting, but almost disappear in front of the beaks. 
Interior with the central portion cream-colored, margin exterior to the 
pallial impression pale clay color; hinge delicate. Length, l/% inch. 
(Deshayes.) 
Type locality, Puget Sound. 
Range. Arctic Ocean to San Diego, California. Also Japan. 
Cardium funcanum Dali, 1907. 
The Nautilus, 20:112. 
Shell small, plump, compact, solid for its size, covered with a smooth 
brown or gray periostracum usually more or less eroded; form varying 
from circular to slightly ovate, with rather prominent slightly prosocoelous 
beaks, situated a little anterior to the middle of the shell; valves moderately 
convex, equal and nearly equilateral, sculptured with numerous (40-58) 
similar, small low, flattish radial ribs separated by much narrower inter¬ 
spaces ; these ribs are not nodulous nor keeled, they are sometimes slightly 
rippled by the incremental lines, and, as usual, are smaller, fainter and 
more crowded distally; the interspaces are rounded; near the dorsal 
margins on each side of the beaks there is an ill-defined narrow space 
which is devoid of ribs; the average number of ribs is about 50; the 
inner margins of the valves are crenulated; the hinge delicate and normal; 
the inner surface of the valves white, polished; the outer surface usually 
shows three or four concentric sulci due to resting-stages. Length, 38; 
height, 33; diameter, 18 mm. (Dali.) 
Type in U. S. N. M. Type locality, Juan de Fuca Strait. 
Range. Southern Bering Sea and south to Monterey, California. 
