LIMNEUS CATASCOPIUM. 



DESCRIPTION. 



Shell oblong-ovate, moderately thin, brownish horn co- 

 lour: tchirls four or five, wrinkled across, convex, de- 

 creasing to an acute apex ; ste/wre well impressed: aper- 

 ture not much dilated, suboval : columella with the fold 

 not remarkably profound. 



SYNONYM. 



L. CATASCOPIUM, S., Jlmer. Ed. of A'icholson's Encycl 

 Article Conc/iology. 



OBSERVATIONS. 



This species is abundant in the river Delaware ; it is al- 

 so an inhabitant of the Schuylkill, and specimens were 

 sent me from Albany on the Hudson by Dr. Eights. 



Its European analogue is the L. peregrum., L., from 

 which it may be distinguished by a deeper fold of the co- 

 lumella and a more acute curvature of the inferior portion 

 of the aperture. The animal is dull yellowish, sprinkled 

 with small, often confluent, paler dots. It may be found 

 abundantly during the recess of the tide, about the smaller 

 streams through which the marshy grounds are drained, 

 in company with several other shells. Like otlicrspccies' 

 both of the present and other allied genera, it not only 

 glides upon the surface of solid bodies, but proceeds along 

 the surface of the water, the shell downward, with regular- 



Pl. .-55. 



