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400 American Seashe lis
I to 2 inches in size, higher than long, poHshed smooth, inflated, fairly
thin and obscurely ribbed. Exterior generally whitish, but may be rose-tinted,
mottled with brown or flushed with purple, yellow or burnt-orange. Interior
similarly colored. With about 60 very fine, subdued radial ribs. A common
shallow-water species. The name serratiim Linne has been erroneously ap-
plied to our Atlantic species by some workers.
Laevicardium vtortoni Conrad Morton's Egg Cockle
Cape Cod, Massachusetts, to Florida and the Gulf of Mexico.
Plate 39I
% to I inch in size, ovate, glossy, similar to laevigatum, but commonly
with brown, zigzag markings and with fine, concentric ridges which are
minutely pimpled. Common in southern New England from shallow water
to 2 fathoms. A food of wild ducks.
Laevicardium pictmn Ravenel Ravenel's Egg Cockle
South Carolina to southeast Florida and the West Indies.
/4 to I inch in height, obliquely triangular in shape, polished and only
moderately inflated. Exterior white or cream with delicate shades or rose
or brown and with a weak, iridescent sheen. A color form has strong,
brown, zigzag streaks. Beaks very low and near the anterior end. Very
faint radial and concentric lines present. Dredged from 75 to 85 fathoms.
An uncommon and attractive species.
Laevicardium sybariticum Dall 1886 (Dall's Egg Cockle, rare, same
range), is more inflated, squarish in shape and with deep-pink breaks.
Laevicardium substriatum Conrad Common Pacific Egg Cockle
Ventura County, California, to the Gulf of California.
Less than i inch in size, obliquely ovate, smooth and slightly compressed.
Color tan with closely set, narrow, radial bands of reddish brown. These
lines are commonly interrupted. Interior cream with cobwebby mottlings
of purplish brown. Very common in such localities as Mission Bay and New-
port.
Laevicardium elatum Sowerby Giant Pacific Egg Cockle
San Pedro, California, to Panama.
3 to 7 inches in height, oval, inflated, slightly oblique, with numerous,
shallow, radial grooves, but the posterior and anterior regions are smooth.