IIKLIX. 67 



Group IX, ARIONTA, Leach, 1820. 



Shell of moderate size, globosely turbinate or depressed, usually 

 with one or three (rarely with two) bands, last whorl declining in 

 front, peristome reflected, thickened, margins approaching. 



Section I, LYSINOE. Adams, 1855. 



.Moderately or narrowly umbilicated, smoothish, epidermis some- 

 times shortly hairy, globosely turbinate, periphery sometimes sub- 

 angulate, last whorl descending in front, peristome reflected, margins 

 approaching, impinging on the umbilicus below. West Coast of 

 ^'urth America. H. FIDELIS, Gray. 



Aglaja, Albers, 1860, is a synonym. 



Subsection I, HELMINTHOGLYPTA, Ancey, 1887. 

 Surface vermiculately rugose, H. ARROSA, Gould. 



Subsection II, ODONTURA, Crosse and Fischer, 1872. 



Subglobose, with narrow umbilicus, granular epidermis in fresh 

 individuals shortly hairy. Southern Mexico, Guatemala. H. GHIES- 



BREGHTII, NySt. 



Subsection III, LEPTARIONTA, Crosse and Fischer, 1872. 



Smoothish, small, thin, whorls about 4}, last whorl descending in 

 front, with a single brown band, periphery rounded, peristome 

 shortly reflected, umbilicus narrow. Mexico. H. FLAYESCENS, 

 Wiegm. 



Subsection IV, PRATICOLA, Strebel, 1880. 



Orbicular, small, last whorl constricted behind the aperture, peris- 

 tome shortly reflected, lipped within. Texas, Eastern Mexico. H. 

 BERLANDIERIANA, Mor. 



This group is Hyyromia (Risso) in part, of American authors. 



Subsection V, MICRARIONTA, Ancey. 



Shell thick, small, depressed, peristome shortly reflected, thickened 

 within. Islands of So. California. H. FACTA, Newc. 



More depressed, and geographically separated from Praticola, 

 but very close to it. 



Subsection VI, PCECILOSTOLA, Ancey, 1887. 



Imperforate, rather thin, globosely depressed, whorls few, the last 

 large, peristome thickened, white, thinly reflected. Andes Regions 

 of So. America. H. FARRISI, Pfr. 



