The Produclivily of Pish Food in Oneida Lake 155 



Data are not at hand with which to compare the bathy- 

 metrical distribution of Oneida Lake mollusks with those of 

 other lakes in New York. Recently, Maury, of Cornell Uni- 

 versity ('16, p. 32), reports dredgings made in deep water in 

 Cayuga Lake but no Ust of species is given nor the depths 

 attained. Dredgings were made in water as deep as 200 feet 

 and the details of the results would be of great interest. Maury 

 says of this work : " These dredgings proved conclusively 

 that Mollusca are abundant from the shore line to about ten 

 feet, after twenty-five feet thay become very scarce, the dredge 

 yielding only a few Amnicolas and broken fragments of shells, 

 the occupants having apparently been preyed upon by fishes. 

 In the greater depths no signs of Mollusca or of plants were 

 found. There was only a very fine grey mud entirely barren 

 of life. We believe this to be due partly to the great depth of 

 the Finger Lakes ; but much more to the extremely low tem- 

 perature of the water of Cayuga Lake, which even in mid- 

 summer is very cold except in sun-warmed shallows." 



Outside of New York State, however, mollusks have been 

 reported at considerable depths. Robertson ('15) dredged in 

 Georgian Bay and obtained the following species at depths 

 down to 20 fathoms (120 feet) : Amnicola limosa, A. lustrica, 

 A. eniarginata, Valvata tricarinata, V. sine era. Walker ('97, 

 p. 97) records Lytnncea, Sphceriiim, Pisidium, Planorbis, Val- 

 vata, and Amnicola as abundant at a depth of 25 metres (82 

 feet) in Lake Michigan near High Island. 



As Amnicola, Valvata, Sphcerium, and Pisidium have been 

 found at great depths in the lakes mentioned it is highly prob- 

 able that they will be found in the deepest part of Oneida Lake 

 which attains a depth of 55 feet or more at the east end. 



The distribution of mussels in depth and on character of 

 bottom in other regions is of interest when compared with the 

 data obtained in Lower South Bay and vicinity. Headlee and 

 Simonton ('04, pp. 173-179) made a study of the mussels of 

 Winona Lake, Indiana. Eight species were found, four of 

 which inhabit Oneida Lake. The lake examined is a glacial 

 kettle hole lake the maximum depth of which is 86 feet. The 

 shores are as a rule " composed of sand and gravel which shade 



