EXPLANATION OF PLATE XIV. 



Shells, radular teeth, etc., of Hydrohioides and Amnicola. 



Hydrobioides avarix, sp. nov. 



Figs. 1, 2, 2a, 26, 2c. — Shells, opercula and radular teeth of specimens 

 from a small stream near Fort Stedman. 



(Figs. 1, 2, 2a, 26, xca. 1\ ; radular teeth highly magnified.) 



Hydrobioides nana, sp. nov. 

 Pig, 3. — Type-specimen from the Lile Lake, x ca. 19. 



Hydrobioides nassa (Theobald). 

 Figs. 4, ia. — Radular teeth and male organ. 

 (Fig. 4 highly magnified ; fig. 4« x 20.) 



Hydrobioides physcus, sp. nov. 

 Figs. 5, 5a. — Same structures. 



(Fig. 5 highly magnified ; fig. 5a X 20.) 



Amnicola alticola, sp. nov. 



Figs. 6, 6a. — Shell and operculum ; the operculum as seen from within. 

 Length of shell 2-75 mm. 



