36 COELOCENTRUM. 



whorl is dirty flesh-color, sharply defined in the umbilical re- 

 gion, but lost toward the aperture. The 13 remaining whorls 

 are flatly arcuate, rapidly tapering above, while below the con- 

 traction is hardly noticeable. The last whorl is only shortly 

 free, and somewhat turned outward. The umbilical carina 

 is only weakly modeled, while the dorsal keel or cord dis- 

 tinctly projects, especially at the beginning. The sculpture 

 consists of fine, sharp, close-set and but slightly arcuate rib- 

 lets on the upper whorls, which on following whorls become 

 more spaced, more irregular and weaker. On the last half of 

 the last whorl they become close again, but without increasing 

 much in sharpness. On the penultimate whorl, which is 14% 

 mm. broad, I count about 100 of these rib-like folds. The 

 cuticle appears under the lens finely wrinkled, the wrinkles 

 running spirally, so that there is a sort of spiral striation. 

 The internal column is only moderately swollen within each 

 whorl. Its exterior is rather closely set with with very fine 

 lamellae, the free edges of which, especially in the lower 

 whorls, are finely serrate. The whole internal column is whit- 

 ish flesh-colored. The aperture is triangular-oval, the peri- 

 stome shortly but pretty strongly expanded, nearly reflexed, 

 white outside and within, and only weakly thickened. The 

 interior shows a yellowish-bronze zone behind the white peri- 

 stome, which then passes into dirty violet-white. The com- 

 presed and oblique columellar fold is distinctly visible. The 

 umbilicus is represented by a narrow chink only. 



Coban, Guatemala (Sarg). 



Ccclocentrum anomalum STREBEL, Beitrag iv, p. 59, pi. 6, f. 

 8 ; pi. 14, f . 5. v. MARTENS, Biologia, p. 270. 



Violet chocolate-colored, with the base of the last whorl 

 dirty flesh-colored. Internal column densely set with finely 

 serrate vertical lamellae. Description from Strebel's account. 

 C. TURRIS (Pfeiffer). PI. 12, figs. 1, 2, 3, 4, 5. 



Shell deeply rimate, cylindric below, tapering above, very 

 thin, light brown. Surface sculptured with fine, arcuate rib- 

 striae, which are sharp, close and regular above, weaker and 

 somewhat irregular on the lower half of the shell. Whorls 

 remaining 16 to 24, convex, very slowly increasing in width, 



