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394 American Seashells
Genus Echinochama P. Fischer 1887
Echinochmna cornuta Conrad Florida Spiny Jewel Box
North Carolina to both sides of Florida to Texas.
Plate 37g
I to I % inches in length, quadrate in outHne and rather obese and heavy.
Lunule distinct and broadly heart-shaped. With 7 to 9 rows of moderately
long, stoutish spines, between which the shell is grossly pitted. Exterior
creamy-white; interior white or flushed with bright pinkish mauve. Attached
to a small pebble or broken shell by the right valve. Common from 3 to
40 fathoms, and commonly washed ashore.
Echinochama arcinella Linne (True Spiny Jewel Box, pi. 37h) from the
West Indies to Brazil has 16 to 35 (commonly 20) radial rows of slender
spines. The shell is not as obese nor as heavy as cornuta. The subspecies
califorjiica Dall (pi. 37e) is very similar, with slightly longer spines and with
a more compressed shell. It ranges from the Gulf of CaHfornia to Panama
in offshore water.
Superfamily LEPTONACEA
Family LEPTONIDAE
A group of small, fragile, inflated, translucent clams which are parasitic
or commensal on other marine creatures or are active crawlers like the gastro-
pods. Most species brood their young inside the mantle cavity. The family
is also named Erycinidae and Kelliidae.
Genus Kellia Turton 1822
Shell unsculptured, inflated and oval-oblong. Lateral teeth present.
2 cardinal teeth in the right valve.
Kellia laperousi Deshayes La Perouse's Lepton
Alaska to Panama.
% to I inch in length, oval-oblong, rather obese and with small beaks
near the center. Shell fairly strong, chalk-white, but commonly covered
with a smooth, glossy, greenish to yellowish-brown periostracum which,
however, is commonly worn away in the beak area. Very common. Found
attached to wharf pilings among mussels and chama shells.
Genus Lasaea Brown 1827
Shell very small, beaks nearer one end. Teeth the same as in Kellia.