The Proditctivity of Pish Food in Oneida Lake 159 



lusks. GilUa eggs were also abundant especially on ell-grass 

 (Vallisneria). Eggs of the fresh-water pulmonates, Lyntncea, 

 Physa, Planorhis, etc., are not as numerous in the summer as 

 in the early fall. This abundance of eggs shows a high rate 

 of reproduction and indicates that these genera probably repro- 

 duce themselves rapidly. 



5. Quantitative Studies. In the chapter on the Compo- 

 sition of the Bottom Fauna quantitative studies have already 

 been considered in detail so that it is only necessary here to 

 mention those species of mollusks that are the most abundant 

 in individuals in Lower South Bay and vicinity. Sphcerium 

 vermontanum, Atnnicola oneida, Valvata iricarinata, Galha 

 catascopium, and Planorbis parvus are the leading species in 

 shallow water, and Elliptio complanatus, Sphcerium solididum, 

 Amnicola bakeriana niniia, J^alvata sincera, V. tricarinata, 

 Planorbis parvus, and young Galba catascopium in the deeper 

 water. Tables Numbers 16-35 bring out the relative abun- 

 dance in a striking manner. 



List of Species 



This list includes both the species collected from Lower 

 South Bay and vicinity in 1916, and the species listed in 191 5 

 (Baker, '16, pp. 252-286). It is thought that the complete list 

 of species thus far recorded from the lake will be of greater 

 value than the list of species collected in 1916 alone. Species 

 additional to the 191 5 list are indicated by an asterisk. 



CLASS PELECYPODA 



order prionodesmacea 



Family Unionid/E 



Genus Elliptic Rafinesque 



I. Elliptio complanatus ("Solander" Dillwyn). 



This is the most abundant mussel in the area under discus- 

 sion, being found in nearly every habitat examined, including 

 all depths of water and all varieties of bottom. There is con- 

 siderable variation in the size and form of the shell, individuals 



