194 M. Deshayes' Monograph of Deiitalium, 



D. corneum. Lam., Anim. sans vert. v. p. 345, n. 15. 

 D. coarctatum. Brocchi, Conchyl. Subap. p. 264, n. 9, pi. 1, f. 4. 

 D. incrassatum. Scmerhy, Min, Conch, pi. 79, f. 3, 4. 

 Habitat in mari Australise ? — Foss. in Anglia, Gallia, et Italia. 



Shell slightly curved, ash-coloured, becoming thinner towards its pos- 

 terior extremity, contracted at the opening, which is furnished with a 

 more or less obtuse thickening, its edges being sometimes worn, at others 

 sharp. Transverse strise closely set, very fine, more or less regular, oc- 

 casionally becoming coarse. 



Length 1 inch 2 lines. 



40. D. SUBULATUM, Desh. D. testd tereti, arcuatd, angustd, subulatdy 

 acuminatd, albido-fuscd, maculis nebulosis fuscis; aperturd coarc- 

 tatd. 



Habitat ? 



Resembles the preceding, but is longer, narrower, more curved, and 

 pointed ; the thickening of the contracted opening is not so short, and 

 beyond it the lip, instead of being reflected, becomes thin and sharp ; 

 the apex is much more acute, and its hole smaller ; its colour is also dif- 

 ferent, being white at the apex, and light fulvous in the remainder of its 

 extent with deeper clouded irregular spots. External surface perfectly 

 smooth, vnthout either longitudinal or transverse strige. 



Length 1 inch 3 lines. Diameter of the base rather more than 1 line. 



41. D. CRASSUM, Desh. D, testd arcuatd, abbreviatd, crassd, sep" 

 ■ tem costatd; aperturd coarctatd. 



Foss. in Gallia. 



Shell short, curved, thick, solid ; base broad, but rather owing to the 

 thickness of the shell than to the size of the opening. Ribs seven, the 

 odd one median dorsal, prominent, coarse, perfectly symmetrical, attain- 

 ing their greatest developement near the opening, where they are lost in 

 the marginal thickening. Marginal thickening considerable, narrow, 

 separated from the remainder of the shell by a slight depression ; becom- 

 ing thin anteriorly, and terminating in a sharp margin. Striae of growth 

 irregular. 



