125] 



Family PUPAD^. 



Shell cylindrical, with generally obtuse apex, the whorls 

 numerous and nearly equal ; aperture small, rounded, with 

 expanded or reflected lips, and generally armed with teeth or 

 laminse within. Minute in size in most of the North American 

 species. 



Animal. — Tentacles very small or wanting ; foot short, obtuse 

 or pointed behind. 



ItemarJcs. — These shells are the smallest of all the terrestrial 

 mollusca inhabiting the United States (except P. incana, which 

 is a large species, but belongs to a West Indian group). They 

 are so minute, indeed, that it requires the strictest scrutiny of 

 the damp ground, moss, or decayed wood inhabited by them, in 

 order to detect their presence, a difficulty which is much increased 

 by their color, which is dull and earthy. 



Crenera. 



1. ClONELLA, Jeffreys. Oblong-acuminate, smooth, polished; 



aperture small, oval, with a short, arcuate, more or less 

 truncated columella. 



2. Stbnogyra, Shuttleworth. Cylindrically turrited, generally 



truncate at apex, epidermis corneous, shining ; aperture 

 small, oval, columella truncate. 



3. Macrocbramus. Turrited or conical, apex attenuated, last 



whorl angulated around its base ; aperture oval, peristome 

 not continuous nor reflected, except over the columella. 

 Generally white with stripes or spots of darker markings. 



4. Pupa, Draparnaud. Cylindrical, minutely perforate, size 



very small, aperture small, lip expanded or reflected, gene- 

 rally toothed within. Animal with superior and inferior 

 tentacles. 



5. Strophia, Albers. Shell large, with obtuse apex, the whorls 



generally covered with transverse ribs. Lip thickened and 

 reflected, its extremities connected by a thick callus; colu- 

 mella dentate. 



West Indian, 



