DENTALIUM-L.E7IDENTALIUM. 107 



We scarcely endorse the view of Jeffreys, who seems not to have 

 considered the slit form distinct. The somewhat meagre series of D. 

 rubsece7is seen (Jeffreys and Academy Coll.) is scarcely sufficient for 

 definite decision. D. fissura Lamarck, with which Philippi and 

 Costa identified this shell, is a Miocene species. D. fissura Sowerby 

 may be a large, pale D. splendidum. See under Fastiaria. 



D. MALzANi ' Dunker ' Clessin. PI. 19, fig. 3. 



Shell slender, lightly curved, slowing increasing, smooth, some- 

 what solid, shining, semipellucid ; white, with rose colored apex. 

 Aperture round, margin acute ; apex abruptly truncated. Length 

 33, diam. 3'5 mill. (Clessin). 



Goree, West Africa (Malzan). 



D. malzani Dkr. in Paetel's Catalog, p. 593 (no description). — 

 Clessin, Conchyl. Cab., p. 42, pi. 11, f. 6 (1896). 



Type in the Stuttgart Museum. Occurred with " D." goreannm, a 

 species of Ditrupa or some allied genus, which Clessin (in the year 

 1896! ! !) describes as a new Dentalium. How slowly moves this 

 old World ! D. malzani may be the same as D. rubescens Desh. 

 No distinguishing characters have been brought forward. 



D. sicuLUM Deshayes, n. n. PI. 19, fig. 6. 



Shell cylindrical, somewhat curved, continuous, whitish, polished, 

 with extremely close and delicate strife. (Costa). 



Adriatic Sea and Ionian Is. (Costa). 



D.politum Costa, Faun. Reg. Nap., Tubibranchi, p. 23, pi. 1, f. 

 4. Not D. politum Linn. — D. siculum Desh. in MS. card cata- 

 logue. 



Costa describes the shell as smooth and lustrous, of a shining 

 milk-white color, somewhat diaphanous, with fine circular strise seen 

 only under the lens, and indistinct annular swellings (such as occur 

 in D. ebuniewn) ; and the apex is formed as in many Mediterranean 

 tusk-shells, the orifice being small with thick walls and a slight 

 notch, as shown in the figure. Length 1 inch, 6 lines. Deshayes 

 gives no further information on his card, which is dated 1870, and 

 probably had not seen the shell. Costa's species has been referred 

 doubtfully to D. rubescens Dh. by some authors, but if the annula- 

 tion described be really present, that species apparently is different. 



D. LiODON Pilsbry & Sharp, n. sp. PI. 21, figs. 37, 38, 39. 



Shell moderately curved, rather slender, attenuated toward the 

 apex, thin but not fragile. Subtransluceut bluish-white, opaque white 



