The Productivity of Fish food in Oneida Take 129 



absence of associated animals is noteworthy. An area of about 

 5,000 square feet north of the club house on Norcross Point 

 (Habitat No. cxxiv) contains several species of Potamogeton. 

 The water is two feet deep and the bottom of hard sand. Life 

 from a 64 .square inch unit is shown in Table No. 32. On the 

 basis of this average there are 247,500 moUusks and 90,000 

 associated animals, or a total animal population of 337,500 

 individuals.* 



Table No. 32. Population of Vegetation, Haiutat No. CXXIV' 

 Mollusks 



Physa Integra 6 



Flanorbis parvus 12 



Bythinia tentaculaia 4 



22 specimens 



As.sociated animals 

 Amphipoda 



Hyalella laiickcrhockeri 4 



Trichoptera 



Caddis-fly larvae 3 



Acarina 



Water mite I 



8 specimens 



In Habitat No. cxxviii, off Norcross Point, in 5^/2 feet of 

 water, sand bottom, a large area of Vallisneria spiralis occurs. 

 Leaves from a unit area (64 square inches) were examined 

 and contained the animal life shown in Table No. 33. The 

 extent of the territory covered by this plant was not ascer- 

 tained. It was studied over an area fully 50 by 100 feet (5,000 

 square feet), and in this place there must be on this basis 

 45,000 mollusks and 56,250 associated animals, a total calcu- 

 lated population of 101,250.! 



* Computation : 5,000 square feet X 144 square inches = 720,000 

 square inches -^ 64 square inches = 11,250 unit areas X 22 moHusks^ 

 247,500 mollusks and X8 associated animals = 90,000 associated ani- 

 mals, a total animal population of 337,500, individuals. 



t Computation : 5,000 square feet X 144 square inches = 720,000 square 

 inches -^ 64 square inches =^ 11,250 unit areas X 4 mollusks = 45,000 

 mollusks, and X 5 associated animals ^ 56,250 associated animals, a 

 total calculated population of 101,250. 



5 



