60 PROCEEDINGS OF THE ACADEMY OF [Jan.^. 



IV. Subgenus ORTHOCYCLOPS Forbes. 



5. Cyclops modestus Herrick. 



V. Subgenus MICROCYCLOPS Glaus. 



6. Cyclops varicans Sars. 



VI. Subgenus EUCYCLOPS Glaus. 



7. Cyclops serrulatus Fischer. _ 



Not described in this paper, but the most abundant form. 



8. Cyclops prasinus Fischer. 



VII. Subgenus PARAGYCLOPS Glaus. 



9. Cyclops phaleratus Koch. 



10. Cyclops fimbriatus var. poppei Rehberg. 



In the above Kst, subgenus III is omitted since it only contains 

 C. ater Herrick, a form not found thus far in this locality. This 

 arrangement is taken directly from Forbes' paper of '97. 



Description of C. viridis var. insectus Forbes and C. serrulatus 

 Fischer are not given in this paper. The latter form is perhaps the 

 commonest one of the genus and will not be mistaken for any other 

 since no other American form approaches it in morphological details. 

 Forbes has discussed the synonymy in his paper of '97, but since 

 that time several European investigators have established new 

 species and varieties all intimately related with the type form. A 

 careful comparative study of these new forms will be necessary before 

 the description of C. serrulatus Fischer can be brought up to date. 

 It is known to be a most variable form. Size and stylet proportions 

 are rarely constant in individuals taken at the same locality' and 

 even in the same collection. 



Bibliography. 



Brewer, A. D. '98. A Study of the Copepoda found in the Vicinity of Lin- 

 coln, Nebraska. Studies from the Zool. Lab. of the University of Nebraska, 

 Lincoln, Nebraska, No. 29, Article XIII, pp. 119-138, pi. VII. 



Byrnes, E. F. '03. Heterogeny and Variation in some of the Copepoda of 

 Long Island. Reprinted from the Biol. Bulletin, Vol. V, no. 3, August, '03. 

 pp. 152-168, 5 figs. 



'06. Two Transitional Stages in the Development of Cyclops signnlus var. 



coronatus. Reprinted from Biol. Bulletin, Vol. X, no. 5, April, '06. 



'09. The Fresh Water Cyclops of Long Island, Cold Spring Harbor Mono- 

 graphs, No. VII, March, '09. Pub. by the Brooklyn Inst, of Arts and 

 Sciences. Fifteen plates, 43 pp. 



Chichkoff, G. '06. Copepodes d'eau douce do Bulgarie, Zool. Anzeig., Band 

 31, pp. 78-82. 



Claus, C. '63. Die freilebenden Copepoden, mit besonderer Berlicksichtigung 

 der Fauna Deutschlands, der Nordsee und des Mittelmeeres. 230 pj)., 

 37 pis. Leipzig. 



Cragin, F. W. '83. A Contribution to the History of the Fresh-water Copepoda. 

 Trans. Kansas Acad. Sci., Vol. VlII, pp. 06-80, pis. I-I\'. 



