The Relation of Mollusks to Fish in Oneida Lake — 239 
Rhopalocerca tardigrada Diesing. Fluke. 
From mantle of Anodonta fluviatilis (cataracta) and 
Anodonta lacustris (=marginata) (Leidy, 1877, a, p. 202; 
1858, p. 110). 
Heterostomum echinatum Diesing. Fluke. 
From oviduct of Campeloma decisum (Leidy, 1877, a, p. 
202). 
Cotylaspis insignis Leidy. Fluke. 
From branchial cavity of Anodonta fluviatilis (cataracta) 
and lacustris (marginata) (Leidy, 1858, p. 110). 
Aspidogaster conchicolor von Baer. Fluke. 
From pericardial cavity of Lampsilis radiata, Lampsilis 
cariosa, Lampsilis nasuta, Lampsilis purpurea, Anodonta 
marginata and in oviduct of Campeloma decisum (Leidy, 
1851, b, p. 224; 1877, b, p. 260). 
Fasciola hepaticum Linneus. Sheep Laver-Fluke. 
This fluke lives as a sporocyst in the respiratory cavity of 
a small pond snail (Galba truncatula) common in Europe. 
The young escape from the snail and migrate to grassy 
meadows where they are eaten by sheep and later infest the 
liver of this animal. In this country, in the western states, 
the little snail Galba humilis modicella is suspected of being 
the intermediary host of this fluke (Ward, 1895, pp. 
246-252). 
The Unionide or fresh-water mussels are subject to infesta- 
tion by a large number of parasites including trematodes, 
oligochxetes, infusorians, and the mites, Afar. Kelly (1899) 
found that in 44 species examined, all but 5 were infested. 
The parasites observed are listed below: 
Aspidogaster conchicolor von Baer. This fluke was 
found in 37. species, including Strophitus edentulus, 
Anodonta grandis, Lampsilis luteola and L. ligamentina 
which are Oneida Lake species. The pericardial and nephri- 
dial cavities were the regions infested (p. 404). 
