34 COELOCENTRUM. 



little convex, numbering 12 in the adult truncate example, 

 about 24 in all, to judge from comparison with a young speci- 

 men; the height of the visible part of a whorl varying from 

 % to % of its diameter, the middle whorls being not so high 

 as the upper and lower ones; the last seven whorls nearly 

 equal in diameter, the preceding ones gradually diminishing 

 upwards, so that the whole shell is turrete, but not properly 

 fusiform. Base of the last whorl rounded, with a rather 

 broad and shallow spiral furrow in the prolongation of the 

 suture, instead of the usual angular line (fig. 3). The aper- 

 ture, in the single, perhaps not quite perfect, adult specimen 

 is scarcely produced beyond the suture, and its edges are very 

 thin and shortly expanded; the opening is 17 mm. high and 

 16 mm. broad, irregularly rhomboidal, with an obtuse angle 

 at the base, but rounded above. The columellar plait inside 

 the aperture is rather strong, pale orange, and ascends in a 

 straight oblique line. The costulaB of the columellar axis 

 are numerous, about as broad as their interstices, and descend 

 in a straight line (v. Mart.). 



E. Guatemala: Livingston, in the Bay of Honduras (0. 

 Stoll). 



Coelocentrum gigas MARTENS, Biologia Centrali Americana, 

 Moll., p. 267, pi. 16, f. 27, 28, a-c (Nov., 1897), 



The largest species known. " Fig. 4 represents a younger 

 individual, which has not yet lost so many whorls." 

 C. PFEFFERI Ball. PI. 11, figs. 5, 6. 



Shell subcylindric, with Sy 2 whorls, attenuated above, 

 rounded below, solid, decollate, the whorls gently rounded 

 with a distinct suture, without spiral sculpture, transverse 

 sculpture of delicate, hardly arched, little raised, crowded 

 lines, subequal over the whole surface ; base rounded, the basal 

 area bounded by an obscure line, umbilicus reduced to a mi- 

 nute perforation, aperture rounded below, slightly angular 

 above, usually free but occasionally adnate to the body whorl ; 

 axis normal, small at the decollation; color pale livid pink, 

 whitish near the aperture. Length 43, maximum diameter 15, 

 diam. at decollation 7 mm. (Dall). 



Ocozucuantla [ Ocozocoautla] , State of Chiapas, Mexico 

 (E. W. Nelson) ; types No. 107367, U. S. N. M. 



