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Family HELICID^. 



Shell depressed, or globosely elevated, strong, striate, with 

 the epidermis colored, frequently banded, opaque, lip either 

 margined within, or expanded, or appressed and reflected. 

 Aperture sometimes toothed. 



Animal snail-like, not so narrowly lengthened generally as 

 in Helicellidse. Buccal plate arcuate, thick, with transverse 

 rounded ribs. 



Lingual dentition. — Uncini and laterals the same in form, 

 the former 1-2 dentate or notched irregularly, the latter 1 

 dentate. 



Suhfamilies. 



Hygkomiin^. — Shell not toothed, lip not reflected, some- 

 times expanded, more or less thickened witiiin the margin. 



Mesodontik^. — Shell frequently toothed, lip broadly re- 

 flected and appressed. 



HYGEOMIIN^. 



Genera. 

 * Umhilicate. 



1. Hygeomia, Eisso. Globosely depressed, not angulated, 



generally hirsute; whorls 5-7, convex; aperture round- 

 ed or widely lunate ; lip acute, slightly expanded and 

 thickened within. Corneous, generally unicolored. 

 Size small. 



Inhabits east of Eocky Mountains. 



2. Aglaja, Albers. Depressed-conoidal, sometimes ob- 



scurely angidate; lip thickened within, encroaching a 

 little on the umbilicus. Yellowish-brown, almost al- 

 ways banded. Size large ; surface malleate. 



Inhabits California and Oregon. 



