Great Lakes; found but once during the present 

 survey. 



24. Achtheres c orpulentus Kellicott. Parasitic 

 on the gills and in the gill cavity of the lake herring 

 in Buffalo Harbor, the Niagara River, and at Dun- 

 kirk, New York; not found during the present survey. 



25. Achtheres pimelodi Kroyer. Parasitic on 

 the gill arches of the bullhead at Put -in -Bay, Ohio; 

 not found during the present survey. 



26. Argulus stizostethi i Kellicott. Parasitic on 

 the outside surface of the walleye pike in the Niagara 

 River near Buffalo; not found during the present sur- 

 vey but said by fishermen to infest this fish during 

 midsummer in considerable numbers. 



27. Ergasilus ce ntrarchidarum Wright. Parasitic 

 on the gill filaments of the pike -perch and the small - 

 mouth black bass; very few infested fish found during 

 the survey. 



28. Ergasilus caeruleus Wilson. Parasitic on 

 the gill filaments of the walleye pike in the western 

 end of the lake; not obtained during the present survey. 



29. Lernaea cruciata (Le Sueur). Parasitic in 

 the flesh of the redeye in Lake Erie at Erie, Pennsyl- 

 vania, and in the Sandusky River, and in the flesh of 

 the sunfish in Cattaraugus Creek; only a few fish in- 

 fested. 



Cladocera 



30. Acroperus angustatus Sars. Found in very 

 small numbers at Point Abino, in the inner bay at 

 Long Point, and in the ponds at Point Pelee, all on 

 the Canadian Shore. Eaten by the yellow perch; con- 

 fined to the marginal zone. 



31. Acroperus harpae Baird. Abundant along 

 the Canadian shore, but present only at Stony Point, 

 Michigan, and Dunkirk, New York, on the Amer- 

 ican side. Eaten by a small unidentified fish caught 

 in the Helgoland trawl near the mouth of Cattaraugus 

 Creek; marginal zone only. 



32. Alona affinis (Leydig). Well distributed 

 along the Canadian shore but rare on the American 

 side, and nowhere rated as abundant. Eaten by yel- 



low perch, carp, and goldfish; marginal zone only. 



33. Alona costata Sars. Found at only two of 

 the marginal stations in very small numbers. Stony 

 Point, Michigan, and Port Stanley. Eaten by yel- 

 low perch and an unidentified shiner. 



34. Alona guttata Sars. A few specimens were 

 found in the ponds on Point Pelee during the present 

 survey; reported as very abundant there by Bigelow 

 (1922). 



35. Alona quadrangularis (O. F. MUller). 

 Found only in very small numbers at Turkey Point 

 and at Stony Point. Eaten by carp and redhorse 

 suckers; confined to the marginal zone. 



36. Alona rectangula Sars. Found at 3 mar- 

 ginal stations on the Canadian shore, at Dunkirk, 

 New York, and in a mud washing at Eighteen Mile 

 Creek, everywhere in very small numbers. 



37. Al onella excisa (Fischer). Rare at Point 

 Abino, Port Stanley, in the ponds on Point Pelee, 

 and in Lackawanna Pond in the suburbs of Buffalo. 

 Eaten by carp sucker; confined to the marginal zone. 



38. Alonella nana (Baird). Found only at Point 

 Abino and in ponds on Point Pelee. Eaten by carp 

 and bullhead; confined to the marginal zone. 



39. Bosmin a long irostris (O. F. MUller). Found 

 at 12 of the marginal stations evenly divided between 

 the Canadian and American shores, and in the plank- 

 ton of both the littoral and lacustric zones during 

 June and July. Its numbers were less in July than in 

 June and it did not appear at aU during August or 

 September; it breeds in Rondeau Harbor. In the 

 open lake it was more in evidence at the two ends, 

 and less so through the middle. Its highest percent- 

 age of the macroplankton was in the surface tow off 

 Ashtabula, Ohio, in the littoral zone. Eaten by 

 goldfish, the green-backed shiner, and the Cayuga 

 minnow. 



40. Bosmina longispin a Leydig. Found in the 

 marginal zone at 3 stations on the Canadian shore 

 and at Sandusky Bay; 1 or 2 specimens were taken in 

 the littoral zone along with the preceding species. 

 Breeds in Rondeau Harbor, where it was very abundant 

 and where the tow was filled with young in various 



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