HELIX. 137 



three-lobed, much contracted by the lip and teeth ; lip 

 white, sometimes edged with brown, widely reflected, 

 with two projecting teeth on the inner margin, the one 

 near its junction with the body- whorl acute and prominent, 

 the other, in the base of the aperture, long, lamellar, and 

 but little prominent ; pillar-lip with a very prominent, 

 white, curved tooth, projecting nearly perpendicularly 

 from the shell, and forming one boundary of the aperture ; 

 umbilicus covered with a white callus, the continuation 

 of the reflected lip ; base convex. 



Greatest transverse diameter, nearly one inch. 



GEOGRAPHICAL DISTRIBUTION. Inhabits all the North- 

 ern and Western States, and the Atlantic States as far 

 south as South Carolina, and probably may be found in 

 every State of the Union, and in Canada. It is most 

 common in the Western States, where it attains its 

 greatest size. 



REMARKS. This is a remarkable species, easily dis- 

 tinguished from every other by its rough, hairy exterior, 

 prominent falciform tooth on the columella, and con- 

 tracted, trilobate aperture. As in all other imperforate 

 species with reflected lip, the umbilicus remains open until 

 the lip is completed ; and, of course, the young shells are 

 destitute of the most striking characteristics as above 

 described. It resembles H. tridentata, Say, in its upper 

 surface, so much that, when placed side by side, they 

 might be considered identical ; but on the lower surface 

 the resemblance no longer holds ; for, though the aper- 



VOL. II. 18 



