320 MEXICAN LEPTINABIA. 



margin is much arcuated 'beneath, thick and strongly twisted 

 above, the twisting ending towards the underside in a strong 

 projection. The tooth on the parietal wall is compressed, 

 lamelliform, almost equally distant from the columella and 

 from the outer margin, and does not reach far into the in- 

 terior of the aperture. The dimensions of the two specimens 

 are: 



Long. 9%, diam. .5 ( ?) ; apert. long. 5y 2 , lat. 3 (?) mm. 



Long. 8, diam. 4%; apert. long. 4, lat. 3 mm. 

 In the larger example a part of the outer wall of the aper- 

 ture is broken away; therefore the diameter, both of the 

 whole shell and of the aperture, must have been greater when 

 entire. The other specimen possesses an equally developed 

 tooth or plate on the parietal wall; it is probably also full- 

 grown. In neither shell can I see what Canon Tristram 

 meant by the words "margine dextro suleato"; but as he 

 gives the length as 10% and the diameter as 6 mm., he seems 

 to have had a larger specimen than ours" (v. Mts.). 



39. L. STOLLI Martens, PI. 42, figs. 26, 31. 



Shell ovate-globose, rimate, thin, lightly striatulate, pale 

 yellowish, glossy. Whorls 5, convex, with moderately im- 

 pressed suture, the base of the last whorl rounded. Aperture 

 subvertical, trapezoidal, the outer margin well arched, basal 

 margin widely rounded, columellar margin a little concave, 

 dilated, broadly truncate at the base and encircled with a 

 distinct fold. Parietal wall uniplicate in the young shell. 

 Length 7, diam. 5, aperture 4.5x3 mm. (Martens). 



Western Guatemala: Betalhuleu, in woods under decayed 

 leaves, rare (Stoll). 



L. stolli MARTS., Biologia, p. 316, pi. 18, f. 9, 9a (1898). 



The most globose of all the species within our limits (Mex- 

 ico and Central America). A young shell (fig. 31), quite 

 distinct by its form from L, elisce, shows the parietal plate 

 very clearly, but in the full-grown examples no trace of it is 

 to be seen (Marts.). 



40. L. CONVOLUTA Martens. PI. 42, figs. 33, 34. 



Shell conic^ovate, imperforate, diaphanous, finely striatu- 



