stages of development. It is eaten by goldfish and the 

 yellow perch. 



41. Camptocercus macrurus (O. F. MYiUer). A 

 few specimens were found in the ponds on Point Pelee. 

 It has not thus far been identified in the stomach con- 

 tents of any fish. 



42. Camptocercus rectirostris Schoedler. Found 

 at 10 stations of the marginal zone, 6 on the Canadian 

 and 4 on the American side. At one station on either 

 side it was listed as abundant and these are evidently 

 its breeding areas. This species was reported and fig- 

 ured by Vorce from the vicinity of Cleveland, but was 

 referred by him to the wrong species. Eaten by red- 

 horse sucker and the picconou. 



43. Ceriodaphnia laticaudata P. E. Mliller. 

 Found at 9 stations of the marginal zone, all but one 

 in the center or at the western end of the lake; abun- 

 dant only in the ponds on Point Pelee; not found in the 

 other zones. Eaten by carp and yellow perch. 



44. Ceriodaphnia pulchella Sars. Found in very 

 small numbers at 5 marginal stations on the Canadian 

 and 3 on the American shore. Eaten by yellow perch 

 and carp. 



45. Ceriodaphnia quadrangula (O, F. Milller). 

 Found at Cedar Bay, Long Point, Inner Bay, ponds on 

 Point Pelee, and Sandusky Bay. Eaten by shiners. 



46. Ceriodaphnia reticulata (Jurine). Found at 



4 marginal stations on the Canadian and 3 on the Amer- 

 ican shore. Breeds in the Inner Bay at Long Point and 

 in a small pond of the Cattaraugus Creek drainage. 

 Eaten by carp. 



47. Chydorus faviformi s Birge. Reported by 

 Bigelow (1922) from the ponds on Point Pelee; not ob- 

 tained during the present survey. Not found in the 

 stomach of any fish. 



48. Chydorus gibbus L illjeborg. Found at Point 

 Abino and Rondeau Harbor on the Canadian shore and 

 at 3 stations on the American side; confined to the 

 marginal zone. Eaten by the bullhead. 



49. Chydorus globosus Baird. Found only in the 

 marginal zone at Point Abino, Rondeau Harbor, and 

 Point Pelee, and breeding at the two latter places. 

 Eaten by yellow perch. 



50. Chydorus latus Sars. Found only at 4 mar- 

 ginal zone stations on the Canadian shore; breeding in 

 the ponds on Point Pelee. Not identified in the food 

 of any fish. 



51. Chydorus sphaericus (O. F. IvTMler). Found 

 at 6 Canadian and 5 American marginal zone stations, 

 and washed out of the sand on Crystal Beach. Breed- 

 ing in small ponds of the Cayuga Creek and the Cat- 

 taraugus Creek drainages. Eaten by the redhorse 

 sucker, carp sucker, and bullhead. 



52. Daphnia longispina (O. F. MUller). Under 

 this specific name are included all the varieties which 

 possess a crest of any sort, and which for the purposes 

 of this survey do not demand varietal separation. Found 

 at nearly every marginal station on both sides of the 

 lake as well as in the littoral and lacustric zones. In 

 the two latter zones the combined varieties of this spe- 

 cies were more numerous than pulex during June and 

 July, but less numerous during August and September. 

 In June they were more abundant at the surface, in 

 July and August at the bottom, and in September at the 

 surface again, thus giving evidence of vertical migra- 

 tion. All the varieties appeared during the summer but 

 mendotae was the prevailing one in June and July, while 

 galeata was more common in August and September. 

 The varieties typica and galeata seemed most abundant 

 along the Canadian shore, and mendotae along the 

 American shore. They are eaten by the Cisco, the yel- 

 low perch, and an unidentified shiner. 



53. Daphnia pulex (de Geer). Found at practic- 

 ally every station in all 3 zones and its percentages of 

 the macroplankton were often from 75 to 100 percent 

 of the total. Next to Leptodora it is the largest cla - 

 doceran in the lake and this combined with its ex- 

 ceptional abundance makes it the most important spe- 

 cies in the macroplankton. In the marginal and lit- 

 toral zones it was much more abundant along the Amer- 

 ican shore than on the Canadian side. Indeed the only 

 stations at which it was entirely absent from the tow wen 

 in the marginal zone on the Canadian shore. 



Stingelin and Weismann have found that this spe- 

 cies has two reproductive periods each year, a larger 

 one from the middle of July to the middle of August, anc 

 a smaller one in November. They also found that the 

 spring generation which hatched from the winter eggs 

 (ephippia) was different from the fall generation which 

 hatched from the summer eggs. The observations of 

 other investigators combined with those made during 



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