64 Illinois State Laboratory of Natural History. 



6. Cffclop.s riridls Jnrine, 



Either the typical form or its varieties occur everywhere 

 in the fresh waters of the United States. It is the commonest 

 form of the temporary i)onds. 



((. var. ])r('risj)'niosvs Herrick. 



Ii. var, 'ni.scetii.t Forhes. 



7. C}icJop>i ])i('iiHj)i(l(itiis Clans. 



This species is of the widest range and greatest abundance. 

 It is the commonest Cyclops in the Great Lakes. 



8. Ci/clops rer^al'is Fischer, 



Occurs in small numl)ers in Lake Geneva, Wisconsin. 



II, Subgenus Macrociicloj)^ Clans, 



9. Ci/eloj)>i fiisots Jurine. 



Occurs sparingly in the ponds and lakes of Wisconsin, 

 Michigan, Illinois, and Massachusetts. 



10. Cyclops alhulns Jurine. 



Rather a common species throughout the whole range of 

 the genus. 



III. Subgenus Homoei/clops n. subgen. 



11. Cyclops (iter Herrick, 



Very rare throughout the Mississippi Valley, Also in Lake 

 St, Clair (Kofoid). 



IV, Subgenus Ortliocjidops n. subgen, 



12. Cyclops modestns Herrick, 



An uncommon species in the lakes and streams of Wyo- 

 ming, Alabama, and the north central States. 



V. Subgenus M'icrocy clops Clans. 



13. Cyclops hicolor Sars. 



, Eare in Wyoming, Illinois, Wisconsin, Michigan, and Min- 

 nesota, 



14. Cyclo])s r((y}c<iiis Sars, 



A fairly common species throughout the range of Cyclops 

 in North America, 



