Turner — Ecological Notes — Cladocera and Copepoda. 153 



free from even a suggestion of ice. Although I did not 

 take the temperature of the water in those Ohio ponds, 

 yet, since no ice had formed on the surface, it was cer- 

 tainly higher than zero centigrade. It seems then that 

 a temperature which would be low enough to induce clad- 

 ocerans of a cold clime to produce ''winter eggs" is not 

 necessarily low enough to induce those of a milder climate 

 to do so. My records do not show whether or no male 

 cladocerans occur in Augusta; the Copepoda, both the 

 Calanidae and the Cyclopidae, produce numerous males. 

 It is not claimed that observations made throughout one 

 winter are sufficient to warrant the assertion that the 

 Cladocera of Augusta never form "winter eggs;" but 

 this does not militate against the statement made above. 



COPEPODA. 



Calanidae. 



diaptomus Westwood. 



1. diaptomus sanguineus Forbes, var. minnetonka Her- 



rick. 



Diaptomus sanguineus, Forbes, '76, pp. 15, 16, 23; fig. 24, 28-30. 

 Diaptomus minnetonka, Herrick & Turner, '95, pp. 71-72; PI. XIII., 



Fig. 8-10. 

 Diaptomus sanguineus, Schacht, '97, pp. 133-137, PI. XXIIL-XXV. 



Near Augusta, this form, which is abundant, seems to 

 be confined to marshes and ditches having a temperature 

 of from 10° to 16° C. Associated with it, in addition to 

 the entomostracans mentioned in table I., were : — young 

 crayfish, Brancippi, Assellidae, gammarids, water-boat- 

 men, hydraclmids, and planarians. 



2. diaptomus stagnalis Forbes. 



Diaptomus stagnalis, Forbes, '82, p. 646; PI. VIII., Fig. 8, 10-12, 14. 

 Diaptomus stagnalis, Herrick and Turner, '95, pp. 66, 67; PI. III.; 



XIII., Fig. 11, 13. 

 Diaptomus stagnalis, Schacht, '97, pp. 138-141; PI. XXVIII. , Fig. 2. 



Alike D. sanguineus, this species is an inhabitant of 

 marshes and ditches ; but is more abundant. I have never 

 found D. sanguineus except in company with D. stagnalis, 



