1910.] NATURAL SCIENCES OF PHILADELPHIA. 535 



deciduous in several narrow bands on the last whorl. Spire low-conic, 

 the apex rather acute. Whorls 4^, tubular, the first H nearly smooth, 

 the rest having a sculpture of fine, close, thread-like radial strise, 

 closer and less regular on the last whorl. There is no trace of corruga- 

 tion. The last whorl is rounded, with no trace of a keel or ridge on 

 the base. Aperture nearly circular, not angular above, slightly 

 oblique, the thin peristome in contact with the preceding whorl for a 

 very short distance only. 



Alt. 10, diam. 14 mm. 



Operculum evenly and moderately concave outside, bearing a spiral 

 lamina of fully 7 whorls outside of the central depression. This 

 lamina flares broadly outward, leaving but a narrow space between 

 the turns; and its outer end is not concrescent with the preceding 

 turn. The inside is convex in the middle. Diameter 5 mm. 



Jamaica. Type No. 101,141, A. N. S. P., from the G. W. Tryon 

 collection. 



A species of Chitty's group No. 1, apparently related to the small 

 variety of A. notatus, but with no trace of a basal keel or corruga- 

 tion. 



35 



