M. Deshayes' Monograph of Dentalium, 185 



rounded, more prominent near the apex, diminishing insensibly, and 

 disappearing near the opening, interrupted by a few striae of growth. 

 Opening narrow relatively to the length of the shell. 

 Length 2 inches. Diameter scarcely 2 lines. 



14. D. ACUTICOSTA, Desh. D. testd tereti, subarcuatd, subulatdj duo- 



decim ad sexdecim costatd ; costis tenuihus angustis, acutis, ad aper- 



turam evanescentibus, 



D. striatum. Sowerby, Min. Conch, pi. 70, f. 4. 



Foss. in Anglia, prope Barton. 



Elongated, narrow, pointed, smooth towards the opening, covered with 

 ribs in the remainder of its extent. Ribs varying in number from twelve 

 to sixteen, small, narrow, slightly prominent, acute, rather distant from 

 each other, diminishing insensibly from the apex to the base, where they 

 disappear altogether. Striae of growth rather frequent. 



Length 3 inches. Diameter at the base scarcely 2 lines. 



15. D. PSEUDO-SEXAGONUM, Desh. D. testd tereti, subulatd, subar-^ 

 ctiatd, grised, tenaiter striatd, extremitate posticd sex angulatd. 

 Habitat ? 



Greyish-white, semitransparent, slightly curved, pointed ; apex with 

 six regular, prominent angles, between each of which are numerous striae 

 which cover the shell, the angles disappearing quickly at about one-fourth 

 or one-third of the length of the shell. The striae of growth are very 

 fine, and frequently regular, intersecting transversely the longitudinal 

 striae. 



Length from 1 inch 9 lines to 2 inches. Diameter of the base scarcely 

 2 lines. 



16. D. MULTISTRIATUM, Desh. D. testd tereti, subrectd, albidd, mul- 

 tistriatd, striis tenuibus, confertissimis, aliquantisper seriatim submct- 

 culatis. 



D. fasciatum ? Gmel.y p. 3737, No. 10. 

 Habitat in mari Indico ? 



Small, narrow, generally sUghtly curved, white, yellowish, or greyish ; 

 entirely covered with fine closely-set striae, continued from the apex to 

 Vol. IV. N 



