DENTALIUM-ANTALIS. 59 



nate thread is weaker until it disappears. Both orifices are circular, 

 the anal one has the upper, and to a less degree the lower edge 

 gently concavely waved, but without a slit. Generally this end is 

 decollate and circular. Length of shell, IT'O ; height of arch from 

 chord, 24; diameter of aperture, 2'12; of anal orifice, 0*5 mill. 

 {Ball). 



Off the Carolina coast, in 22 to 52 fms., sand ; at U. S. Fish Com- 

 mission Stations 2598, 2608 and 2612. Station 2405, in the Gulf of 

 Mexico between the Mississippi delta and Cedar Keys, Florida, in 30 

 fms., sand. 



D. taphrium Dall, Bull. M. C. Z., xviii, Blake Rep., p. 422 

 (1889) ; Bull. U. S. Nat. Mus., no. 37, p. 76. 



A couple of specimens were obtained, dead and white, in 182 fms., 

 coral sand, off Havana, Cuba, by the U. S. Fish Commission. These 

 though decollate behind, were about nine millimeters longer ante- 

 riorly than any of the more northern specimens, without gaining 

 much in diameter. The added part was almost destitute of sculpt- 

 ure. {Dall). 



D. PHANEUM Dall. PI. 20, fig. 24 (enlarged). 



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

 curve chiefly in 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 longitudin- 

 ally by about twenty-five very fine, 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 lon- 

 gitudinal strife; 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 diameter, 0*5 ; maximum deviation of 

 the curve from a chord drawn between the ends, 3*2 mill. (Dall). 

 Off Honolulu, Hawaiian Is., 298-351 fms. (Albatross). 



Dentalium phaneum Dall, Proc. U. S. Nat. Mus., xvii, 1894, p. 

 686, pi. 26, f. 1. 



This species is perhaps most nearly allied to D. antillarum Orb- 

 igny, of the Antilles, a species which diflTers in its sharper and more 

 numerous ribs, which become more prominent toward the apex in- 

 stead of obsolete. 



