48 University of Michigan 



reflected edge of the central is particularly elongate, and the 

 mesocone is also slender and lanceolate. The first lateral is 

 turned slightly inward and the entocone has moved up on the 

 outside of the mesocone. Both of these characters increase 

 in prominence through the series of laterals, until in the elev- 

 enth tooth the entocone is very small and is high up on the 

 outside of the mesocone. This tooth is shaped very much 

 like what may be termed the first marginal, only the latter is 

 bicuspid. The first i8 marginals are bicuspid, and arranged 

 in an almost horizontal row. The individual teeth (No. 21 is 

 typical) are not so obliquely placed as are the tricuspids of 

 G. gundlachi, or those of this species. The thirtieth tooth shows 

 a minute, additional cusp outside of the others, and is the first 

 of 19 tricuspids. With these, the transverse row begins to 

 curve obliquely backward. These tricuspid' teeth are even 

 larger and better developed than are the bicuspids. 'With the 

 reduction in size of the outermost teeth comes an additional 

 cusp on the forty-ninth, which is the first of 8 or 9 quadricus- 

 pids of rapidly reducing size. The two outer denticles, which 

 are often absent (even in adjacent rows in the body of the 

 radula this much variation was noticed), are practically 

 cuspless. 



Enconulus (?) pittieri (von Martens) (1892). — One dead 

 specimen from humus among rocks, near the Laguna de 

 Catemaco. This specimen agrees very well with the original 

 description. It differs from B. elegantula by the marked cari- 

 nation of the whorls, the more conical shape, the greater prom- 

 inence of its radial wrinkles, which extend to within one whorl 

 of the apex and which, in regularity and prominence, are some- 

 what reminiscent of Strobilops, and the coincident relative 

 obscurity of the spiral striations, which, however, are quite 

 noticeable on the lower side. It differs from G. gundlachi 



