Synopsis Fresh-Water Moi^eusca 31 



Key to the genera of Lithoglyphincc. 

 r Shell imperforate or narrowly perforate 2 



[ Shell widely umbilicate _ . . . -?. 



f Peritreme sinuous, lip effuse below, verge winged Fluminicola. 



2. { Peritreme continuous in same plane, verge simple Gillia. 



\ Peritreme very oblique, lip effuse above, verge bifid Soiiiatogynis. 



{ Shell spirally striate, depressed, turbinate, widely umbilicate 



3-1 Cochliopa. 



[ Shell smooth, globose-turbinate, umbilicus narrower, but deep. Clappia. 



Genus COCHLIOPA Stimpson, 1865. 



^^^^^^ . Shell depressed-conic; base concave, umbilicus large and 



^^!^^^^^^ deep; aperture oblique; operculum corneous, subspiral. 



V\,.vV^Ai)?^ Rostrum of moderate size; tentacles rather long and tap- 



^^^^^^ J ering. Teeth of the radula multicuspid, basal denticles on 



Fic^ 106"^^ central tooth 2 or 3 on each side. Verge rather elongated, 



^'^ compressed, geniculated and bifid. 



Type: Auinicola rozvellii Tryon. 

 Example : . C. riograndcnsis P. and F., fig. 106. 



Genus CLAPPIA Walker, 1909. 



Shell minute, spiral, dextral, globose-tur- 

 binate, narrowly but deeply umbilicate. Spire 

 ,iiMi\ short; body whorl large; whorls round; aper- 1/2^^ 



m^^\ ^^^^^ large; lip simple; columellar lip thin, ap- r^^x) 

 pressed to the body-whorl only at the upper {^W 

 end; operculum paucispiral, nuclear whorls ^<-^ 

 large, slowly and regularly increasing. Fig. 108 



Fig. 107 Rachidian tooth as in Somatogynis, in- 



termediate tooth with a long peduncle and a strong tooth projecting from 

 the infero-anterior angle, laterals multicuspid. 



Fig. 109 

 Type: C. clappii Walker, fig. 107. Operculum, fig. 108. Radula, fig. 109. 



