16 Descriptions of New Species of Helicidm. 



iusculis, ultimo spira breviori, subcarinato ; apertura quadrata ; peristo- 

 mate simplici, revoluto-expanso, albo; marginibus approximatis, colu- 

 mellari dilatato. 



Shell sinistral, perforate, ventricose-conic, with fine oblique 

 incremental striae, horn-colored ; spire conical, somewhat acute ; 

 whorls seven, rather convex, the last shorter than the spire and 

 obtusely keeled ; aperture subquadrate ; peristome simple, revo- 

 lutely expanded, white ; margins approximated ; columellar 

 margin dilated. 



Length, 0.75 inch (19 millim.). Breadth, 0.40 inch (10 

 millim.). 



Aperture within, 0.24 inch (6 millim.) long, and 0.18 inch 

 (4J millim.) broad. 



Habitat. Siam. 



Remarks. I am indebted to Dr. T. E. Ingalls of Greenwich, 

 N. Y., for this interesting species. It is allied to B. verier abilis 

 Parreyss, from Transylvania, but is much more ventricose, and 

 differs in having the last whorl keeled, a little after the manner 

 of the genus Cylindrella. Bulimus Chersonesicus Sow., and B. 

 arcuatus Pfr. are also related to it, but differ both in form and 

 coloring. 



3. Helix circumfirmata. 



Testa umbilicata, conoid eo-depressa, oblique leviter striata, fusco- 

 cornea, maculis strigisque rufis obscure radiata ; spira obtusa ; anfracti- 

 bus 7i, subplanis, ultimo subcarinato, non descendente, subtus convexo ; 

 umbilico mediocri ; apertura lunari, intus lamella alba, acuta, subtus 

 peripheriam revolvente externe conspicua, munita ; columella obliqua, 

 callo interno revolvente instructa ; peristomate simplici, acuto. 



Shell umbilicated, depressed-conoidal, with faint oblique 

 incremental striae, brownish horn-colored, obscurely rayed with 



