120 DENTALIUM-EPISIPHON. 



glossy, smooth, with faint growth-striae only. Aperture not oblique, 

 circular. Anal orifice minute, circular, with thin, entire edge. 

 Length 16, diam. of aperture 1 mill. 



Philippines (Cuming). 



D. subrectum JEFFREYS, P. Z. S., 1882, p. 661 (artfully concealed 

 in the text under D.filum'). D.filum in B. M., and, in part, of Sow- 

 erby. 



This form was considered by Sowerby the same as that he had 

 described from Gibraltar as filum; but Jeffreys has indicated the 

 differences recited below, which we have confirmed. Figured and 

 described from the type, a specimen in Jeffreys' collection, now in 

 U. S. National Museum. 



Longer and proportionally broader toward the front or anterior 

 end than D. filum \_gracile Jeffr.], and consequently less slender and 

 thread-like ; also more curved. 



D. LONGUM Sharp & Pilsbry, n. sp. PL 18, figs. 1, 2, 3. 



Shell slender, the length about 15 times the greatest diameter, 

 moderately tapering, rather strongly curved, in section circular. 

 Surface glossy, whitish, somewhat translucent. Sculpture: faint 

 fine growth-striae throughout, running circularly around the tube ; 

 no longitudinal stria3. Aperture circular, not oblique (fig. 3). Api- 

 cal orifice circular, with thin walls and a wide shallow notch on the 

 convex side (fig. 1). Length 18'1, diam. at aperture 1'2, at apex 

 0-5 mill. 



Habitat unknown (type no. 71080, coll. A. N. S. P.). 



D. longum is decidedly more curved than D. fistula, sowerbyi, 

 filum, innwnerabile or subrectum; and in place of the apical sup- 

 plemental tube generally developed in adult individuals of the for- 

 mer four of these, our new species has an open anal orifice with a 

 wide, shallow notch or emargination on the convex side. 



D. attenuatum of Sowerby, 1860 (but not D. attenuatum Say, 

 1824), is probably the same specifically, although as we have not 

 had the advantage of comparing the type of that form, no positive 

 statement can be made. The original figures and description are 

 here given, together with some additional information obligingly 

 furnished by Mr. Sowerby. 



D. attenuatum (pi. 20, fig. 28). Shell thin, tawny, polished, a 

 little arcuate, narrower than D. inversum ; apex slightly emargi- 

 nate. A shining, pointed, very narrow species, with a very slight 



