324 LEPT1NAEIA, S.-G. ISCHNOCION AND PELATRINA. 



This species is closely related to L. gloynii of Curacao, but 

 it differs in having a whorl or two less, is of slightly smaller 

 size, and has a less strongly truncate columella. 



Subgenus ISCHNOCION Pilsbry, nov. 



Shell imperforate, pillar-shaped, many-whorled, with large, 

 smooth apex; aperture small, with strong, entering parietal 

 and columellar lamellae and a palatal fold. Type L. triptyx. 



44. L. TRIPTYX n. sp. PI. 47, figs. 21, 25, 26. 



Shell imperforate, pillar-shaped, very slowly tapering, 

 rather solid, pale yellow. Surface weakly marked with ob- 

 lique growth-striae. Whorls 11, not very convex, the summit 

 rounded, second, third and fourth whorls of equal width and 

 calibre, then the diameter very slowly increases to the last 

 whorl. Suture not deeply impressed, the whorl very finely 

 crenulate below it. Aperture small, the columella concave 

 below, twisted into a large entering fold above; parietal 

 lamella rather low, but entering as far as can be seen. Outer 

 lip acute, provided with an entering lamina in the middle, 

 not reaching to the lip-edge. Length 10.2, diam. 2.2, aper- 

 ture 2 mm. ; diam. at second whorl 1 mm. 



Colombia (R. Swift). 



A remarkable shell, quite unlike any described form. In 

 the type the palatal lamina is discontinuous, that visible from 

 in front being succeeded deep in the throat by a second short 

 lamina. In Fig. 25 the aperture is drawn in oblique view. 

 In a young shell of 8% whorls, 6.5 mm. long, there is only a 

 weak trace of the parietal lamella, the columellar fold is very 

 small, and the palatal lamina weak (pi. 47, fig. 21). 



Subgenus PELATRINIA Pilsbry, nov. 



Embryonic and early neanic whorls vertically striate; 

 columella strongly sinuous, truncate at base; no parietal 

 lamella. Type L. helen<z. 



45. L. HELENA Pilsbry, n. sp. PL 46, figs. 6, 7. 



Shell imperforate, conic-turrite, contracted near the sum- 

 mit, thin, light brown, a little translucent. Surface glossy, 

 the first half -whorl smooth, next two whorls very finely and 



