474 



American Se ash ells 



Subgenus Cochlodesma Couthouy 1839 

 Feriploma leanmn Conrad 



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- 



cordia ornata Orbigny, V^ inch (Atlantic Coast). 



Order SEPTIBRANCHIA 



Fmnily VERTICORDIIDAE 



Genus Verticordia Sowerby 1844 



Subgenus Trigo7iidma Orbigny 1846 



Verticordia oniata Orbigny 



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 



