M. Deshayes' Monograph of Dentaliimi. 191 



The form of this species is pecuUar, being nearly straight in its 

 anterior part, and strongly curved towards its apex. Striae eight to ten 

 in number, very fine, slightly prominent, disappearing near the middle of 

 the shell; between each of these may be seen through a strong magnifier 

 two or three much finer ones, which are lost with them or in some 

 instances are prolonged to the opening. Opening rather large, somewhat 

 oblique, with very thin and sharp edges. Cleft median dorsal, rather 

 deep, but very narrow; apex pointed and fragile ; when this is broken 

 off, the shell resembles D. pseudo-entalis. 



Length 1 inch 7 lines. Diameter of the base more than 2 lines. 



32. D. SECTUM, Desh. D. testd tereti, angustd, subrectd, albidd, 

 subtranslucidd, postice tennaissime striatd, obliqu^ sectd; rimd an- 

 gustd in sectione. 



Habitat in mari Indico ? 



Slightly curved, slender, nearly cylindrical, white, translucid, smooth 

 anteriorly, very finely striate posteriorly; striae numerous, closely set, 

 hair-like, invisible to the naked eye. Hinder extremity not pointed^ 

 obliquely cut on the dorsal surface, and very slightly so on the ventral. 

 Cleft not exceeding in length that of the two sections, seen indistinctly 

 on the ventral surface, because the cut is very short, more prolonged on 

 the dorsal one where the cut is longer. Opening narrow, with a thin and 

 cutting margin. 



Length 1 inch. Diameter of the base 1 line. 



B. Neither ribbed nor striated longitudinally. 



33. D. EBURNEUM, Linn. D. testa tereti subarcuatd, nitidd, aeiitissi- 

 md; striis annularibus regularibus, plus minusve remotis ; apice 

 Jissurd tenuissimd prcelongd. 



Var. a. Testd angustiore; striis annularibus creberrimis; Jissurd 

 longiore. 



D. circinatum. Sowerby, Gen. of Shells, No. XV, f. 5. 



Habitat in mari Indico.— Fow. in Gallia apud Grignon, &c. 



Shell rather large, curved, shining, polished, pointed, rather slender, 

 milk-white, subdiaphanous, composed of a series of nearly transverse 

 oblique rings, separated from each other by a rather deep stria. Apex 



