MARINE MOLLUSCA OF THE UNITED STATES. 143 



parallel with the dorsal and basal margins. Greenish-olive, the 



central space faded purple. 



Length 6, height 1 inch. 



Whole Coast. 



Distinguished from E. ensis of Europe by its greater propor- 

 tionate width of valves. It is altogether a more robust and larger 

 species. 



Found at low-water mark, and considered excellent food. 



Genus SILIQUARIA, Schum. 

 Essai, Nov. Geu., 129. 1817. 



1. S. GiBBA, Spengler. Fig. 332. 



{Solen.) Skrivt. Nat. Selsk., iii. 104. 1794. 

 Solecurtus caribcBus (Lam.) Conrad, Mar. Conch., t. 4, f. 3. 



Shell thick and solid, beaks obtuse and little elevated. Surface 

 with a thick, straw-colored, concentrically wrinkled epidermis. 

 Length 4, height L5 inches. 



Cape Cod, Mass., southwards. 



2. S. DiviSA, Spengler. Fig. 333. 



iSolen.) Skrivt. Nat. Selsk., iii. 96. 1794. 

 Solen fragilis, Pultney, Dorset Cat., 28, t. 4, f. 5. 1799. 

 Solen centralis, Say, Journ. Pliilad. Acad., ii. 316. 1822. 

 Solen Mdens, Chemn. Conch. Cab., xi. 203, t. 198, f. 1939. 1795. 



Shell small and delicate, transversely oblong-ovate, compressed, 

 arcuated, equilateral. Epidermis yellowish, with a purple band 

 from the beaks to the basal margin. 



Length 1.5, height .5. 



Southwards from Cape Cod, Mass. 



Genus SILIQTJA, MUhlfeldt. 

 Entwurf. 44. 1811. 

 Machmra, Gould, Invert. Mass., p. 32. 1841. 



1. S. SQUAMA,' Blainville. Fig. 335. 



{Solecurtus.) Diet. Sci. Nat., xlix. 419. 

 Machmra nitida, Gould, Invert. Mass., 83. 1841. 



Shell thick, oblong-ovate, beaks small ; epidermis very shinino- 

 dark yellowish or greenish-^'^ellow, wrinkled. 

 Length 3, height 1.25 inches. 



Northern Coast, northwards. 



2. S. cosTATA, Say. Figs. 334, also 299 and 300. 



{Solen.) Journ. Pbilad. Acad., ii. 315. 1833. 



Shell thin and fragile, oval-oblong, much compressed, beaks 



