686 BEEP WATER MOLLUSKS AND BR 4.CHI0P0DS—DALL. votsvii. 



from center to center; m the other direction there are about three 

 concentric lamellsB to a millimeter; interior of the shell smooth; an 

 obscure impressed rib marks the course of the fasciole; the margin is 

 slightly radially grooved in harmony with the external radial sculpture. 

 Length of the base, 23; width, 17; height of the shell, 11 mm. 



Station 3473, in 313 fathoms. No. 107011, U.S.N.M. 



This species has a good deal such sculpture as Cranopsis asttiriana, 

 Fischer, but the latter has the radii and concentric lines less elevated. 

 On the plane of the base the apex is 17 mm. behind the anterior margin. 

 Only one dead specimen was obtained. 



Class SCAPHOPODA. 



Genus DENTALIUM, Linusous. 



DENTALIUM PHANEUM, new species. 

 Plate XXVI, tig. 1. 



Shell rather thin, pale straw color, glistening, nearly straight, the 

 curve chietlyin the earlier third; the shell originally is smooth or with 

 few, feeble elevated lines, which in traversing the distance from the 

 apex to the aperture revolve one-fourth of a turn to the right; surface 

 marked by delicate annular lines of growth and longitudinally by about 

 twenty-five very tine, sharp, little-elevated threads, which are strongest 

 about the middle of the shell and more or less obsolete in front and 

 behind ; between these are faint obscure longitudinal striae ; both orifices 

 of the shell are simply circular, the anterior sharp-edged and a little 

 oblique. Length of the shell, 35; anterior diameter, 2.2; apical diam- 

 eter, 0.5; maximum deviation of the curve from achord drawn between 

 the ends, 3.2 mm. 



Stations 3475 and 3476, in 351 and 298 fathoms. Nos. 107025 and 

 107026, U.S.N.M. 



This species is perhaps most nearly allied to D. antiUarum^ Orbigny, 

 of the Antilles, a species which differs in its sharper and more numerous 

 ribs, which become more prominent toward the apex instead of obsolete. 

 Of Pacific species D. numerosum, Dall, a form which occurs in very 

 deej) water from the Galapagos to California abundantly, has the most 

 general resemblance to the present species; but it grows to nearly 

 twice the length, and when closely examined is seen to have a sharply 

 pentagonal posterior section with a conspicuous ventral slit. D. numer- 

 osum is a somewhat straighter and longer shell than D. phaneum. 



DENTALIUM COMPLEXUM, new species. 

 Plate XXVI, fig. 3. 



Shell large, solid, thick, normally white (?), but discolored by sedi- 

 ments after death, so that the specimens received are a pale, rusty 

 brown; surface glossy, sharply grooved, with wider flat interspaces, 

 varying finer or coarser in different specimens; orifices circular, one 



