44 COELOCENTRUM. 



cella, only standing somewhat closer, and in part stronger (see 

 pi. 14, fig. 31). At the suture a fine thread-like thickening 

 may be distinctly seen. The aperture is similar to that of C. 

 tomacella; the peristome is white, the interior dirty yellow in 

 the paler specimen, reddish-brown in the darker ones. The 

 columellar fold is not visible from the front. The umbilicus 

 is not wholly closed, there being a small chink left. 



In the absence of information upon the internal structure 

 of the types of Pfeiffer and the specimens described by Crosse 

 & Fischer, it is impossible to say what relations exist between 

 either of them and the specimens described by Strebel; but 

 from the finer sculpture of the latter, I am disposed to believe 

 that they will prove specifically distinct from Pfeiffer 's type 

 in the Cumingian collection. 



C. DISPAR n. sp. PL 17, figs. 16, 17, 18, 19. 



Shell deeply rimate, cylindric-fusiform, attenuated above, 

 thin, a little translucent, light brown. Surface but little shin- 

 ing, very densely, closely and regularly rib-striate, the riblets 

 strongly arcuate, becoming still finer and closer on the last 

 half whorl, about seven in the space of one mm. on the front 

 of the penultimate whorl. Whorls remaining a trifle over 11, 

 very convex, the last but little narrower than the preceding, 

 having only a slight, obtuse angle in place of the umbilical 

 keel, and with no trace of a cord bounding the base; moder- 

 ately protracted forward. Aperture oblique, irregularly 

 rounded, brown inside ; peristome very light brown, expanded 

 and narrowly subreflexed throughout, the upper margin 

 straightened, left margin somewhat dilated. Columellar fold 

 visible deep within, obliquely entering. Length 30, diam. (of 

 third and fourth whorls from the base) 9 mm.; longest 

 (oblique) axis of the aperture 5%, width 5% nim. 



Internal column large (33/2 mm. wide), strongly swollen 

 below the middle within each whorl, irregularly sculptured 

 with rather low ribs, which are smooth or but weakly serrate, 

 and do not pass below the convexity of the tube. They be- 

 come shorter in earlier whorls, are confined to the convexity 

 in the fifth from the base, and are wanting in still earlier 



