The Productivity of Fish Food in Oneida Lake lyi 



*bo. Amnicola emarginata (Kiister). 



This characteristic species occurred sparingly in water from 

 lo to i8 feet deep on mud and gravel bottoms, usually with the 

 filamentous algsc Cladophora and Spirogyra. 



Family rLEUR0Ci:KiD.-i<; 



(ienus GoNioBASis Lea 



6i. Goniobasis livescens (Menke). 



Found only on boulder and gravel Ixjttoms, on exposed 

 shores or points, in water one-half to four feet in depth. Most 

 abundant in water one to two feet deep on a boulder shore. 

 Many young and immature individuals occurred. The species 

 as it is found in Lower South Bay varies in the obesity of the 

 body whorl, narrow forms occurring, some Avith faint bands 

 resembling the Illinois shell called depygis (see Baker, '02, 

 pi. XXXV, fig. 8). The columella is deeply tinged with purple. 

 Several young individuals were collected, having strongly 

 keeled whorls and measuring 16 mm. in length and 7 mm. in 

 width. 



Family Valvatid.e 



(ienus Valvata O. F. Muller 



62. Valvata tricarinata (Say). 



This small snail was found on all varieties f)f bottom, except 

 sandy clay, and in all depths down to 18 feet. It occurred in 

 numbers on a sand bottom at four feet, on a clay bottom at 

 three and a half feet, on a mud bottom at 8, and 18 feet, and 

 on a gravel bottom at 15 feet. It is rare on gravel and boulder 

 bottoms in shallow water. In this area it is usually associated 

 with the filamentous algae CEdogoniuni and Cladophora. Many 

 young and immature specimens occurred as well as some varia- 

 tions in the position of the carinse. In one individual the center 

 carina was missing on a portion of the body whorl ; other indi- 

 viduals were very flat-spired, only the upper carina being 

 present. 



