1072 Wisconsin Academy of Sciences, Arts, and Letters. 



exopodites of the swimming feet is represented by the formula 

 3, 4, 4, 3. 



The fifth foot is composed of one segment and is armed 

 with a stout serrate spine and two long setae. 



The form of the receptaculum seminis is shown in plate 

 LXXII, fig. 5. 



Average length of the female 1.77 mm. This is the size of 

 my specimens. Herrick gives 2.1 mm. as the average length 

 and Forbes 1.77 mm. to 2.88 mm. 



The deep blue of the ordinary coloration is very marked. 

 This color is most pronounced in the appendages and caudal 

 setae and in the posterior margins of the segments of the 

 cephalothorax. Sometimes the cephalothorax is of a deep red 

 or brown. 



Herrick's description was written from specimens collected 

 in Mud lake, Hennepin Co., Minn. He afterwards stated that 

 it was found from Alabama to Minnesota, and more abund- 

 antly towards the south. Reighard collected it in Lake St. 

 Clair. I have obtained it from Round lake, Twenty-sixth lake, 

 Intermediate lake and Susan lake in Michigan, and from Rush 

 lake, Catfish lake, and Lake Winnebago in Wisconsin. Forbes 

 reports it from the shallow lakes near Havana, 111. These are 

 the only recorded localities. It appears to be a rather rare 

 form. 



CYCLOPS VIRIDIS Jurine. 



Plate LXXII, figs. 7 and 8. Plate LXXIY, figs. 1 and 2. Plate LXXIX, 

 figs. 6 and 7. 



1820. Monoeulus quadricornis var. viridis Jurine, p. 46, pi. Ill, fig. 1. 



1851. Cyc 



1857a. 



1857b. 



1863. 



1863. 



1870. 

 1870. 

 1872. 

 1872. 

 1875. 

 1876a. 



ops viridis Fischer, p. 412, pi. IX, figs. 1-11. 

 brevicornis Claus, p. 32, pi. Ill, figs. 12-17. 

 gigas Claus, p. 207, pi. XI, figs. 1-5. 

 brevicornis Claus, p. 99, pi. IV, fig. 11. 

 gigas Claus, p. 100. 

 brevicornis Lubbock, p. 200. 



Heller, p. 71. 

 Clausii Heller, p. 73, pi. I, figs. 1 and 2. 

 Clausii Fric, p. 220, fig. 13. 

 gigas Fric, p. 220, fig. 14. 

 viridis, Uljanin, p. 30, pi. VII, figs. 3-9. 

 brevicornis Hoek, p. 13, pi. I, figs. 5 and 6. 



