Synopsis Frijsh-Water Moli^usca 



Section PSEtJDOGALBA Baker, 1913. 



Shell as in Galba, but with the inner lip less expanded. Gen- 

 italia in Galba. Lateral teeth tricuspid. 



Fig. 14 



Fig- 15 



Fig. 16 



Type: L. humilis Say, fig. 14. Radula (L. obrussa Say), fig. 15. Animal 

 (ibid.), fig. 16. 



Subgenus STAGNICOLA Leach, 1830. 



Shell varying from elongate to short-ovate; outer lip (usualty) 

 somewhat thickened within ; columella distinctly plicate ; inner lip 

 appressed ; axis slightly or not all perforate ; surface with strong, 

 spirally impressed lines. 



"Prostate elongate-pyrif orm ; penis from three-fourths to four- 

 fifths the length of penis-sac, very thick; lateral teeth bicuspid." 



Type: L. pahistris Miiller, fig. 16. Radula, fig. 18. 



Fig. 17 



Fig. 18 



Section POLYRHYTIS Meek, 1876. 



Shell longitudinally costate. Soft anatomy unknown. 

 Type : L. kingii Meek. 

 Example : L. utahensis Call, fig. 19. 



Family PLANORBIDyE. 

 Key to the subfamilies of Planorbidcc. 



Shell discoidal 



Shell spiral 



Fig. 19 



. . Plaiiorbin<e. 

 Pompholigincn. 



