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, Ill. These are 
the only recorded localities. It appears to be a rather rare 
form. 1 :'! | ! f 
CYCLOPS VIRIDIS J urine. 
Plate LXXII, figs. 7 and 8. Plate LXXIV, figs. 1 and 2. Plate LXXIX, 
figs. 6 and 7. 
1820. 
1851. 
1857a. 
1857b. 
1863. 
1863. 
1863. 
1870. 
1870. 
1872. 
1872. 
1875. 
1876a. 
Monoculus quadricornis var. viridis Jurine, p. 46, pi. Ill, fig. 1. 
Cyclops 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. 
“ gig as 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. 
