SOLECURTUS. 43 



include only siicli as are transversely oblong-oval, covered with 

 obliquely undulating stria), the hinge central, &c., we shall still 

 have left of shells another group, equally distinct in character by 

 their sub-cylindrical, somewhat arched form, compressed at base, 

 the extremities abruptly and usually obliquely rounded, the beaks 

 near the posterior end, the pallial sinus very deep, <fec., answering, 

 in fact, to Mr. Conrad's sub-genus CulteUus. This would, of course, 

 assume the rank of a genus in case the correctness of the above 

 views should be acknowledged. 



Deshayes says that the animal of S. caribous, legumen, &c., ap- 

 proaches closely to that of the true Solen. But, as the genus Solen 

 now admits only shells with terminal beaks, they must still be ar- 

 ranged under Solecurtus. 



Of all the subdivisions which have been made of this genus, Schu- 

 macher's Siliqiiaria would most properly include the two following 

 species. CiiUeUus had been appropriated by him before Conrad used 

 it. The old genus Solen still seems to be very imperfectly sub- 

 divided. 



Solecurtus gibbus. 



Shell sub-cylindrical, thick, rounded posteriorly, obliquely truncated anteriorly ; 



beaks nearest the posterior extremity. 



List. Conch, t 421, fig. 265. 



Solen ffibhus, Spengler, Skrivt. Nat. Selsk. iii. 104 (1794). 



Sokn Guineensis, Chems. Conch, xi. 202, t. 198, fig. 1937. — Dillwyn, Cat. 62, No. 13. 

 — Drug. Encyc. Meth. pi. 225, fig. 1. — Wood, Conch. 129. 



Solen carifxEus, Lam. An. sans Vert. 2d ed. vi. 58. — Hanley. Rec. Sh. 14. 



Solecurtus caribreus, Conrad, Mar. Conch, pi. 4, fig. 3. — De Kay, Nat. Hist. N. Y. v. 243, 

 t. 32, fig. 302. — Gould, Inv. 1st ed. 30. —Woodward, Man. of Moll. 316, pi. 22, 

 fig. 9. 



Solen dedivis, Turt. Conch. Diet. 164, t. 22, fig. 89 (1819). — Flem. Br. An. 460.— 

 Thorpe, Mar Conch. 37. 



Psammobia dedivis, Turt. Br. Biv. 91. 



Solecurtus gibbus, Forbes and Hanl. Br. Moll. i. 267. — Stimpson, Shells of New Eng- 

 land, 22. 



Macha gibba, Gray, Cat Br. Mns. (Br. Moll.) 160. 



Tagetus Dombeyl, Ciienu, Man. de Conch, i. 24, fig. 108. 



Siliquaria gibba, Adams, Gen. ii. 347, pi. 93, figs. 5, 5 a. 



Shell oblong, transverse, very slightly curved, thick and strong, 

 the upper and lower margins nearly parallel ; beaks obtuse and 

 slightly elevated, nearest the posterior end ; this side is narrowest, 

 rounded at the extremity, and having an olituse ridge running 

 obliquely backwards from the beaks ; anterior extremity obliquely 



