44 



tlu' anterior or broader end more or less jagged, owing to that part of the shell being newly 

 formed and consequently nnich thinner than other parts-, at the posterior or narrower end it is 

 usually truncated in adult specimens, and furnished with a very short sloping and oblique pipe 

 or tubular appendage having a pear-shaped orifice-, there is also occasionally at the point on 

 the convex side a notch or groove, in a hne with the front or smaller part of the tubular 

 appendage, and this notch is rarely extended into a short and narrow slit or channel. 

 Length 37 — 42, diam. of aperture 4,5 — 5 mill. 



Distribution. Spitzbergen, Scandinavia, Iceland, and atlantic coasts of Europe, south 

 to Spain, 3 — 1750 fms. Coasts of Maine and Massachusetts north to Bay of Fundy. 



Var. itidicum n. var. PI. VI, fig. 15. 



Stat. 159. o°59'.iS., I29°48'.8E. 411 Metres. Coarse sand. i spec. 



Very similar to D. cntalis but more slender, very glossy and entirely without longitudinal 

 sculpture. Apical notch on the convex side rather deep and extending into a very short 

 (0,04 mill.) .slit. Tubular appendage very long (1,4 mill) slightly laterally compressed. Anterior 

 aperture very little oblique, dorso-ventrally compressed. 

 Length 26, lateral diam. of apert. 3,8, dorso-ventral diam. of apert. 3,4 mill. 



Subgenus Graptacme Pilsbry & Sharp 1897. 

 1897. Graptacuic Pilsbry & Sharp, Man. of Conch., vol. XVII, p. 85. 



Surface sculptured with close, fine, deeply engraved longitudinal striae near the apex, 

 the remainder smooth; or rarely the striae persist half or all the length. Moderate sized or 

 small species, cyhndrical in section, and white or nearly so. (P. & Sh.). 



D. usitahtm is new to this group and bigger than the majority belonging to it. 



The group is distributed over Antillean, Panamic and Indopacific regions. 



K e y t o species. 



Striae covering one seventh and less of shell; length 30 — 40 mill., about 12 — 14 



times the diam aciculitiit. 



Striae covering more than one seventh of the shell; 



a. Length 45 — 65 mill., about g — 11 times the diam Jisitatuui. 



b. Length 40 — 50 mill., about 20 times the diam acutissimuni. 



52. Dentaliiun jisifatum E. A. .Smith. PI. V, figs 6, 7, 8. 



1894. DcntaliHin iisitatuni Smith, Ann. & Mag. Nat. Hist. (6), XIV, p. 168, pi. 4, fig. 16, \6a. 

 1897. Dentalüim iisitatuui Smith. PiLSBRV & Sharp, Manual of Conch., vol. XVII, p. 29, 

 pi. 10, figs. 68, 69. 



Stat. 88. o°34'.6N., 119° 8'.5 E. Celebes Sea. 1301 Metres. Fine grey mud. 6 Spec. 

 Stat. 211. 5°4o'.7S., I20°4S'.S E. Banda Sea. 1158 Metres. Coarse grey mud. 3 Spec. 

 Stat. 300. io°48'.6S., 123° 23'.! PL. Timor Sea. 918 Metre.s. Fine grey mud. 2 Spec. 



