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474 American Seash ells
Feriploma leanmn Conrad
Subgenus Cochlodesma Couthouy 1839
Nova Scotia to off North Carolina.
Lea's Spoon Clam
Plate 28V
I to 1/4 inches in length, ovate, quite compressed, fairly fragile and
white in color. Smoothish. The beaks located near the center of the dorsal
edge of the valves have a natural, radial crease at the anterior end. Chondro-
phore large, points ventrally and is reinforced anteriorly by a low, sturdy
ridge. The muscle scar above the pallial sinus is commonly quite silvery.
Periostracum thin and yellowish. Uncommon just offshore. This was put in
a separate subgenus, Aperiplouia, by Habe in 1952.
Figure 97. Spoon and Dipper Clams, a, Periploum discus Stearns, i y^ inches
(California); b, Ctispidaria ^lacialis Sars, i inch (Atlantic Coast); c and d, Verti-
Verticordia oniata Orbigny
cordia ornata Orbigny, V^ inch (Atlantic Coast).
Order SEPTIBRANCHIA
Fmnily VERTICORDIIDAE
Genus Verticordia Sowerby 1844
Subgenus Trigo7iidma Orbigny 1846
Massachusetts to south half of Florida and the West Indies
Ornate Verticord
Figure 97c, d
^ inch in length, oval to round, compressed and with about a dozen
strong, sharp, curved radial ribs on the anterior % of the valve. The ribs
extend beyond the ventral margin to give a strongly crenulate margin.
Exterior dull and cream-white; interior very silvery. Commonly dredged
off our east coast from 5 to 200 fathoms,
Verticordia (Haliris) fischeriana Dall is similar, but much fatter, %
inch in length, and with about 28 small, finely beaded, radial ribs over the