NIAGARA FALLS AND VICINITY 243 



Valvata tricarinata Say 1822 (Fig. 168). Cyclostoma 

 tricarinata Say (1817. Acad. nat. sci. Phil. Jour. 1 :i|). V a 1 - 

 vata tricarinata Say. (1822. Acad. nat. sci. Phil. Jour. 2:173) 



Shell with four whorls, bearing three prominent cari- 

 nae; growth lines low and indistinct; suture well im- fc^\ 

 pressed; umbilicus large and deep, showing the whorls ,'^\ 



to the apex; revolving lines or carinae placed one on the -^--y 

 upper edge, one on the lower edge, and one on the base. Fig. les vai- 

 Found in Goat island gravel pits. As a recent shell, S*^ *''^''^''^''^^*- 

 it is very common in the river and its tributary streams. 



Valvata sincera Say (Fig. 175). Valvata sincera Say 



(Longs expedition, p. 264, pi. 15, fig. 11 j 



This' shell is more globose than the foregoing and 

 has four whorls, rounded and finely wrinkled; aperture 

 round, not diminishing in thickness at the point of 

 contact; umbilicus large, exhibiting the whorls to the 

 apex. 



sincera! ^^xl^^"^^^^ Fouud associatcd with V. t r i c a r ifu a t a in the 

 gravel on Goat island. 



V. s i n c e r a is not found in Niagara river at the present time, 

 nor is it found in the immediate vicinity. Lime lake is the only 

 locality within a radius of 50 m.iles known to the writer for this 

 species. 



Genus CAMPELOMARafinesque 



Animal with a large foot; head of moderate size, situated some- 

 what back from the end of the foot. Shell thick and soHd, oval; 

 spire somewhat produced; surface smooth and rounded; lip simple 

 and continuous; columellar side entirely covers the um- 

 bilicus. /" - 



Campeloma decisa Say 1817 (Fig. 170). L i m n a e a v 4^ 

 d e c i s a Say (1817. Nick. enc. Am. ed. i) 



Shell imperforate or nearly so, oval with a smooth sur-^g^^JJ^^^^: 

 face; whorls five, rounded, last whorl slightly shouldered ^^ 

 at the suture; aperture oval; lip simple with a callus on the colum- 

 ellar side. 



Locality. Goat island gravel pit. 



Genus limnaea Lamarck. 1798 



Animal provided with a broad head and flattened triangular ten- 

 tacles; mantle thickened in front; foot broad and flat. Shell dex- 

 tral, spire oblong; aperture large and wide; the outer Hp is simple, 

 the inner has a fold on the columella. 



