SOLECURTUS. 43 



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

 obliquely undulating striae, 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, etc., answering, 

 in fact, to Mr. Conrad's sub-genus Cultellus. 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. caribcBifS^ legumen, &c., ap- 

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

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

 ranged mider Solecnrtus. 



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

 macher's Siliquaria would most properly include the two following 

 species. Cultellus 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 glhbus, Spengler, Skrivt. Nat. Sclsk. iii. 104 (1794). 



Solen Gniiieensis, Chemn. Conch, xi. 202, t. 198, fig. 19.37. —Dili.wyn, Cat. 62, No. 13. 

 — Brug. Encvc; Meth. pi. 225, fig. 1. — Wood, Conch. 129. 



Solen caribcFiis, Lam. An. sans Vert. 2d ed. vi. 58. — Haxley. Rec. 8h. 14. 



Solecurtus caribreiis, Coxrad, 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. 



So'en declivis, Turt. Conch. Diet. 164, t. 22, fig. 80 (1819). — Flem. Br. An. 460.— 

 Thorpe, Mar Conch. 37. 



Psammohia declivis, Turt. Br. Biv. 91. 



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

 land, 22. 



Machi gibha, Gray, Cat Br. Mus. (Br. Moll.) 160. 



Tagetus Dombei/i, Ciiexu, Man. de Conch i. 24, fig. 108. 



Siliquaria gibba, AuAMS, 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 ; lieaks obtuse and 

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

 rounded at the extremity, and having an obtuse ridge running 

 obliquely backwards from the beaks ; anterior extremity obliquely 



