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The Relation of Mollusks to Fish in Oneida Lake 151 
campanulatus which formed 40 per cent. of the total con- 
tents. In this connection it is interesting to note that 
Lymnea stagnalis appressa has been noted by Prof. W. M. 
Smallwood, of Syracuse University, to have nearly driven 
Planorbis from the Erie Canal in the eastern part of Syra- 
euse. The data obtained from five specimens of var. lilliane 
is as follows: 
Nos. 1-3, collected on Frenchman Island, in 6 inches of 
water, clinging to stones near shore, Sept. 10, 1915; No. 4, 
Long Island, near shore, Sept. 9; No. 5, Shaw Point, in water 
6 inches deep, on stones, Sept. 14. All specimens full grown, 
35-40 mill. long. 
No. 1. In crop and esophagus. 
Adoeand plant fragments. 02.5205. 0. waesieela. 100 per cent 
No. 2. In crop. 
Bryozoa. 5 statoblasts of Plumatella............ 5 per cent 
Plants. Filamentous alge and plant tissues..... 95 per cent 
No. 3. In crop. 
Bryozoa. 10 statoblasts of Plumatella........... 10 per cent 
Mollusca. 2 Planorbis campanulatus, 2 mill. 
GIS ars pak erie ee Ht 40 per cent 
Fragments of mollusean shell...... 
Plants. ilamentous alee. fiscal « yeles a 
Small seed, Oiip lant 45 spout egetens Ss 50 per cent 
No. 4. In crop. 
Filamentous alge and unicellular plants (diatoms) 100 per cent 
No. 5. In crop. 
Acarina. 1 water-mite; balance of contents digested matter and 
small pieces of sand, white quartz. 
Lymnea is peculiar in possessing a thick crop resembling 
the gizzard of a bird, in which are usually found a few fine 
sand grains, which evidently aid in breaking up or grinding 
the plant tissues torn off by the jaws and radula. Interesting 
notes on this organ may be found in the papers by Colton 
and Baker, cited in this chapter. A series of dissections and 
stomach examinations would undoubtedly prove of great value 
in adding to our knowledge of this subject. 
