248 BULLETIN OF THE 



T. (bigemma var. ?) hircus Dall. Two sharp peripheral threads reticulating 

 short peripheral transverse ribs, nodose at the intersections; the space between 

 the anterior spiral of one whorl, and the posterior one of the next whorl ex- 

 cavated, smooth, with the sutural lips appressed, but no pre-sutural thread; 

 Bubconic; otherwise like bigemma. 



T. abrupta Dall. Sculpture similar to bigemma, but shell smaller, shorter, 

 more inflated and Mastonia-like; with a well marked thread behind the suture, 

 and the transverse waves obsolete. 



T. torticula Dall, Two strong not nodulous spirals undulated by numerous 

 shallow transverse sulci; a fine post-sutural thread; in front of the suture, 

 between it and the posterior primary spiral, one or two fine strongly undulate 

 or subtuberculate threads, the anterior one fainter; base convex with three 

 threads in the young; base smooth, flat and keeled in large not quite adult 

 individuals; shell large, subcylindric, white. 



T. inflata Watson. Two spiral rows of equal tubercles on flat whorls with- 

 out ribs or waves; a marked, hardly undulate thread behind, and a still smaller 

 one before the suture; shell white, elongated. 



T. inflata var. ibex Dall. Like the last, but tubercles more sparse and 

 obliquely set, anterior sutural thread obsolete. 



T. inflata var. filata Dall. Like ibex, but with three fine threads at the 

 suture; shell less cylindrical and proportionally wider. 



C. Without primary spirals. 

 T. cylindrellus Dall. One small post-sutural thread; two or three shallow 

 spiral grooves, cutting numerous oblique transverse sulci; whorls swollen, 

 constricted behind; base very convex; shell small, slender, white. 



Triforis (Sychar) samanse Dall. 



Shell white, opaque, solid, of 12-14 whorls; main body of the shell subcylin- 

 drical, but the apex more rapidly tapered. Sculpture of (on the last whorl) 

 three coarse close-set spirals, covering the whole whorl, each with about thirty 

 closely packed tubercles, like buns strung on a cord, longer axially than in the 

 other direction ; base similarly tubercularly corded with three cords, the inter- 

 spaces deep; canal very short, aperture short, squarish, modified by the sculp- 

 ture. Max. Ion. of shell, 10.0 ; of last whorl, 2.7; max. lat. of shell, 2.8 mm. 



Habitat. Samana Bay, Santo Domingo, in dredgings from about 16 fms. 



This recalls T. decorata C. B. Adams, but in that species the sculpture is not 

 crowded, the tubercles are strictly intersectional, and the ^vhorls do not over- 

 hang each other. 



Triforis (Sychar) bigemma Watson. 



Triforis bigemma Watson, Journ. Lin. Soc., XV. p. 101, 1880 ; Dall, Bull. M. C. Z., 

 IX. p. 81, 1881 ; Watson, Chall. Gastropods, p. 562, pi. xhii. fig. 6, 1885. 



Habitat. Yucatan Strait, in 640 fms. Near St. Thomas, in 390 fms., Chal- 

 lenger Expedition. 



