62 FRESH-WATER SPECIES. 



Diala acuta, Cpr. , is similar, but has a flattened, 

 sharply-angled base. Both of these species live in the 

 sea. 



Truncatella Calif ornica, Pfr., Trun-ka-tel'-la, lives 

 about salt marshes, though it may also be found upon 

 sea-weed and under stones. The shell is less than 

 one-fourth of an inch long, and is nearly cylindrical, 

 with distinct sutures between the whorls. The aper- 

 ture is small and circular, the operculum horny, the 

 color light brown, and the surface smooth. 



Similar to this, but having a more solid shell, is 

 Truncatella Stimpsonii, Stearns. The whorls of this 

 shell are crossed by numerous fine ridges. 



Valvata sincera, Say., Val-va'-ta sin-se'-ra, is a 

 fresh-water species. And thus we turn away from 

 the sea and all its abounding life, to the lakes and 

 rivers. Sometimes, as in this case, we shall travel 

 far inland ; for .the specimen before me came from 

 Franklin, Idaho. It is a minute, flattened, spiral 

 shell, one-eighth of an inch across, consisting of 

 three whorls, which circle around a distinct umbili- 

 cus. The aperture and the operculum are circular, 

 and the color is greenish. 



Valvata wrens, Try on, vi'-rens, is shown in Fig. 



48. It is turban-shaped, bright green in color, 



and its breadth is less than one-fourth of an 



inch. The specimen from which the figure 



was drawn came from Clear lake, California. 



Fig. 48. Fig. 49 represents the shell of Fluminicola 



fusca, Hald., Flu-min-ick'-o-la fus'-ka. This 



name, translated into English, means the 



Tawny River-dweller. 



The shells of this species are about the 

 Fig. 49. size of peas, quite solid, and have a short, 



