246 COLUMELLA. 



size and the relatively smaller aperture." The specimens 

 ' ' occur in deposits of sandy, green marl of undoubted Pleisto- 

 cene age. With them were large numbers of other Pupillida?, 

 as well as other land snails. The entire fauna of the beds is 

 foreign to the region at the present time, but is allied to the 

 present-day Canadian fauna. From this it is supposed that 

 the animals lived just before or during the Glacial epoch." 

 Probably related to C. inornata. 



10. Columella polvonensis (Pils.). PI. 31, fig. 9. 



The shell is narrowly umbilicate ; oblong-ovate ; opaque 

 light buff with cinnamon streaks, the darker color predomi- 

 nating on the last whorl ; rather glossy, smooth save for very 

 weak growth-wrinkles. The spire tapers with convex outlines 

 to the obtuse apex. Whorls moderately convex, the last very- 

 little more ample than the penult. Aperture truncate- 

 rounded; peristome simple and sharp, the eolumellar margin 

 broadly reflected. 



Length 2.5, diam. 1.5 mm. ; 6 whorls. 



Nicaragua: Polvon, Department of Chinandega (McNeil 

 Exped.). 



Pupa polvonensis Pilsbry, Proc. A. N. S. Phila. 1894, pp. 

 31, 61, pi. 1, f. 11. — Sphy rod turn polvonense Pilsbry, Proc. A. 

 N. S. Phila. 1903, p. 769. 



The whorls are less convex than in C. edentula, and the 

 umbilicus is larger. The whitish color is not present in young 

 specimens. The dimensions were not given exactly in my 

 former descriptions. 



11. Columella(?) lata (C. B. Ad.). 



Shell very short, subcylindrical, truncated anteriorly ; pale 

 brown or horn color ; with very regular, rather distant, micro- 

 scopic transverse lines, which are more distinct on the upper 

 whorls ; spire cylindrical ; apex conoid ; whorls five, very con- 

 vex, with a deep suture; last whorl making nearly a right 

 angle between its lateral and anterior surfaces. Aperture 

 about two-thirds of a circle, without teeth; lip not reflected, 

 with a smooth blunt margin ; without umbilicus. 



