144 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Subgenus Fragum Bolten, 1798. 
Cardium biangulatum Sowerby, 1829. 
Zool. Jour., 5:4:367. Conch. III., Cardium; fig. 2. 
Shell somewhat squarely cordate, rounded anteriorly, concavely angu- 
lated and a little produced posteriorly, radiately ribbed, ribs twenty-eight 
in number, the extreme posterior nine of which are narrow, small, round, 
the rest wider, rather flat and peculiarly obliquely or undately crenated, 
interstices between the ribs transversely elevately crenated; interior richly 
stained with purple. (Conch. Iconica.) 
Type in British Museum, Cuming Coll. Type locality, St. Elena and 
Isle of Plata, W. Colombia. 
Range. San Pedro, California, to Panama. 
Subgenus Trigoniocardia Dali, 1900. 
Cardium eudoxium Dali, 1916. 
Proc. U. S. N. M., 52:412. 
Shell small, mottled with lighter and darker rose color, suborbicular, 
inflated, strongly sculptured; radial sculpture of 15 sharp angular ribs 
with subequal interspaces, the keel of the ribs sparsely, regularly, mi¬ 
nutely pustular; on the posterior dorsal area are six additional smaller 
more pustular riblets; the interspaces in all are finely concentrically 
rugose; the hinge is strong; the interior margins deeply sulcate in har¬ 
mony with the radial sculpture; the central part of the interior is whitish. 
Length, 9; height, 9; diameter, 8 mm. (Dali.) 
Type in U. S. N. M., No. 208590. Type locality, Station 3020, Gulf of 
California. 
Range. Catalina Island, California, to the Gulf of California. 
Subgenus L/EVIcardium Swainson, 1840. 
Cardium elatum Sowerby, 1833. 
Proc. Zool. Soc., 1833, p. 84. Conch. III., Cardium; fig. 3. 
Card, testa ovali, obliqua, laevigata, ventricosissima, flava, sulci 
radiantibus plurimis, medianis, prseter posticis, obsoletis; area laterali, 
postica, anticaque laevibus, marginibus edentulis; marginibus ventralibus 
dentatis; epidermide tenue. Long, 4; lat. 3.5; alt. 4.5 poll. (Sowerby.) 
Shell ovate, oblique, very large, radiately ridged about three and 
forty in number, flatly convex, obsolete toward the umbones, extreme 
posterior and anterior areas, smooth; citron yellow, interior white. (Conch. 
Iconica.) 
Found in sandy mud at low water. This is the largest species of 
Cardium with which I am acquainted, its dimensions sometimes far ex¬ 
ceeding those given above. (Sowerby.) 
