BOSTRYX. 105 



insularis, Ehrerib. scutilus. Migh. 



obtusus, Drop. trocbalus, Pfeiff. 



polygyratus, Reeve. Tscbuclii, Trosch. 



Sub-gen. mirus, Albers. 



Shell rimately perforate, sub-cylindrical, thin, pellucid, last 

 whorl anteriorly somewhat ascending; columella arcuated; peri- 

 stome expanded, internally callous, the margins joined by a 

 rather thick, dentated callus. 



Cantori, Phil. 



Sub-gen. peronceus, Albers. 



Shell rimate or perforate, oblong-turreted, or subulate ; 

 whorls convex ; columella receding or obsoletely arcuated ; 

 peristome simple, shortly expanded, the columellar dilated, 

 patent. 



Montagnei, D'Orb. pupiformis, Brod. 



montivagus, D'Orb. scabiosus, Sow. 



nanus, Reeve. terebralis, Pfeiff. 



neglectus, Pfeiff. trichodes, D'Orb. 

 Pazianus, D'Orb. 



Genus BOSTRYX, Troschel. 



Shell turreted, the upper whorls regularly united, the last 

 two unrolled, free, hi-carinated ; aperture sub-quadrate, with 

 the angles rounded ; peristome simple, straight, continuous. 



Ex. B. solutus, Troschel, pi. 75, fig. 10. 



The genus Bostryx w r as founded by Troschel on a re- 

 markable shell brought from Peru by Dr. Tschudi; the 

 last whorls are partly unrolled, and the peritreme is con- 

 tinuous. 



VoL. II. z 



