168 FISSURELLA. 



just within its edge, the two sides projecting upward and contracting 

 it about the middle. Inside porcellaneous white, the perforation- 

 callus bluish, bounded by a black line. Margin denticulated by the 

 ribs of the outside. 

 • Length 24, breadth 17, alt. 10 mill. 



Santiago, Cape Verde Is. 



F. alabastrites Rve. Conch. Icon., f. 27, 1849. — Sowb. Thes. 

 Conch., p. 188, f. 43, 44. — Cremides alabastrites Reeve, Rochebrune, 

 Nouv. Arch, du Mus. 1881, p. 271. 



Diagnostic points are the large orifice, bounded by a dark line 

 and contracted in the middle ; the inside callus also bounded with 

 black ; and the strong ribs of the exterior. 



F. coarctata King. PI. 39, fig. 94. 



Shell ovate, attenuated anteriorly, radiately very closely striated ; 

 orifice oblong, very much contracted in the middle ; greenish-white, 

 very closely rayed with black lines around the orifice. (Rve.) 



Island of Santiago, Cape Verde Archipelago. 



F. coarctata King, Zool. Journ. v, p. 339, 1831. — Sowerby in 

 Conchol. Illustr., f. 22, 37.— Reeve, Conch. Icon. f. 32.— Sowb. 

 Thes., p. 188, f. 60. — Cremides coarctata King, Rochebrune, Faune 

 de FArchip. du Cap Vert, in Nouv. Arch, du Mus. 2d. Ser. iv, 1881, 

 p. 271. 



A species allied to humphreyi, alabastrites, verna, and glaucopsis — 

 species described from the Cape Verde Islands. Distinguished by 

 its large bipartite orifice and fine radiating strise. 



Reeve gives Benguela, W. Africa, as the habitat. Rochebrune 

 says that both recent and fossil specimens are in the Paris Museum. 



F. verna Gould. PL 42, figs. 49, 50, 51. 



Shell symmetrical, solid, depressed-conical, of a greenish-ash color, 

 and broadly rayed with dark purple ; apex nearly central, purple 

 at tip ; surface with a thin epidermis and with about 20 to 30 

 depressed, nearly equal flattish ribs, the intervening spaces of about 

 an equal width, and subdivided by one or two striae. Aperture 

 regularly oval, edge coarsely scalloped. Interior of a pale verdigris 

 or leek-green color. Fissure small, oval, surrounded interiorly with 

 a finely striated callus margined with bluish. (Gld.) 



Length If, breadth 1|, alt. I inch. 



Porto Praya, Cape de Verde Is. 



F. verna Gld. Proc. Bost. Soc. N. H. ii, p. 155, Aug. 1846 ; U. 

 S. Expl. Exped. Moll. & Shells, p. 366, f. 472a, b, c. 



