2 LEPTACHATINA. 



delicate species like this, with the mere semblance of a colu- 

 mellar fold, may properly constitute a distinct group, to 

 which the name Leptachatina (leptos and Achatina) might 

 be given." In 1852 Gould included three additional species 

 (cerealis, guttula and accincta). 



Pfeiffer in his numerous writings employed Leptachatina 

 only as a section of Achatinella. Hartman (1888) also con- 

 sidered Leptachatina as a section of Achatinella. H. & A. 

 Adams accorded Leptachatina subgeneric rank. 



Pease was the first author to use Leptachatina, as a genus. 

 Since then several authors have considered Leptachatina to 

 be a separate genus. Baldwin, Ancey and Sykes have taken 

 this view, which is supported by the differential features of 

 the shell no less than by the oviparous reproduction. 



Classification of species. 



Leptachatina may be divided into several groups accord- 

 ing to the form of the shell, the closeness of the whorls, and 

 other characters noticed below. 

 I. Embryonic whorls smooth. 



1. Aperture simple. Subgenus LEPTACHATINA s. str. 

 a. Surface smooth, nearly smooth, or slightly striate. 



A. The shells are elongate or acuminate; the 

 aperture more or less angulate at both ends. 



Group of L. acuminata, species 1-4. 



B. The shells are small, slender, somewhat tur- 

 rited, glossy, transparent; aperture more or 

 less rounded below. 



Group of L. sandwicensis, species, 5-12. 



C. The shells are small, slightly striate, usually 

 dark chestnut, somewhat turrited and slightly 

 thicker than those of B. 



Group of L. cerealis, species 13-17. 



D. The shells are larger than those of B and C, 

 turrited ; the upper whorls closely coiled. 



Group of L. gracilis, species 18-20. 



E. The shells are small, slender, subcylindrical, 



