1094 Wisconsin Academy of Sciences, Arts, and Letters. 
middle or end of the second cephalothoracic segment. The 
setae of the antennal appendages are unusually long. 
The spinous armature of the terminal segments of the exo- 
podites of the swimming feet is 4, 4, 3, 3. This is an un¬ 
unusual armature. 
The fifth foot (PI. LXXVIII, fig. 3) is three segmented. 
The first segment is short and without armature. The second 
segment is nearly square and bears a seta on its outer distal 
angle. The third segment is narrower, longer than wide and 
hears two apical setae. Frequently the outer of these setae is 
bent over the inner. 
Length of the females 1.2 to 1.25 mm. 
This was first described by Herrick from Alabama, and he 
afterwards reported finding it in Minnesota. I found it in 
two localities in Wisconsin and Forbes reports it from Wyom¬ 
ing, and states that it is an uncommon species in the north 
central states. I have received specimens from R. A. Spaeth 
collected at Haverford, Pennyslvania, and from C. F. Baker 
collected at Auburn, Alabama. 
CYPLOPS SERRULATUS Fischer. 
Plate LXXVIIL, Figs. 5-9, Plate LXXIX, Figs. 4 and 8. 
1851. 
1853. 
1857. 
1863. 
1863. 
1863. 
1870. 
1872. 
1875. 
1876a. 
1878. 
1878. 
1880. 
1882. 
1882. 
1883. 
1883. 
1884. 
1884. 
Cyclops serrulatus Fischer, p. 423, pi. X, figs. 22, 23, 26-31. 
“ “ Lilljeborg, p. 158, pi. XY, fig. 12. 
“ “ Claus, p. 36, pi. I, figs. 1-3. 
“ “ “ p. 101, pi. I, figs. 1 and 2, pi. IY, fig. 12, 
pi. XI, fig. 3. 
“ “ Sars, p. 254. 
“ “ Lubbock, p. 197. 
“ “ Heller, p. 72. 
“ “ Fric, p. 222, fig. 18. 
“ “ Uljanin, p. 34, pi. VIII, figs. 1-8. 
“ “ Hoek, p. 22. 
“ “ Brady, p. 109, pi. XXII, figs. 1-6. 
“ “ var. montanus Brady, p. 110, pi. XXII, figs. 7-14. 
“ agilis Rehberg, p. 545. 
“ “ Forbes, p. 649. 
“ serrulatus Herrick, p. 230, pi. V, figs. 1-5, pi. VII, fig. 10. 
“ “ G. M. Thompson, p. 96, pi. XI, figs. 19-22. 
“ pectinifer Cragin, p. 6, pi. IY, figs. 1-7. 
“ serrulatus Herrick, p. 157, pi. 0, figs. 17-19. 
“ “ var. elegans , Herrick, p. 158. 
