1078 Wisconsin Academy of Sciences, Arts, and Letters. 
have some means of designating the forms, ~and it makes little 
difference to them whether they are called species or varieties. 
This is my excuse for proposing the use of these varietal 
names. 
The European type of viridis does not have the spine of 
the second segment of the fifth foot separated by a joint, has 
for the spine formula of the terminal segment of the exopodite 
of the swimming feet 2, 3, 3, 3, and has the internal margin 
of the furcal rami ciliate. There are, among the European 
forms, however, all the variations noted in the American 
forms. The typical form is vastly the more common in 
Europe, while in America americanus is the most widely dis¬ 
tributed variety, ingens and parcus being comparatively rare. 
CYCLOPS BICUSPIDATUS Claus. 
Plate LXXIII, figs. 1-11; Plate LXXIX, fig. 11. 
1857a. 
1863. 
1863. 
1870. 
1872. 
1875. 
1876a. 
1880. 
1880a. 
1882. 
1882. 
1882. 
1883. 
1883. 
1883. 
1884. 
1884. 
1885. 
1885. 
1886. 
1888. 
1890. 
1890. 
1891. 
1891. 
1891. 
1891. 
1892. 
Cyclops bicuspidatus Claus, p. 209, pi. XI, figs. 6 and 7. 
“ “ “ , p. 101. 
“ pulchellus Sars, p. 246. 
“ bicuspidatus Heller, p. 71. 
“ “ Fric, p. 221, fig. 16. 
“ odessanus Schmankewitsch. 
“ bicuspidatus Hoek, p. 17, pi. I, figs. 7-11. 
“ pulchellus Rehberg, p. 543. 
“ helgolandicus Rehberg, p. 64, pi. IY, fig. 5. 
pulchellus Vejdowsky, p. 63, pi. VII, figs. 11 and 12. 
“ Thomasi Forbes, p. 649, pi. IX, figs. 10, 11 and 16. 
“ navus Herrick, p. 229, pi. Y, figs. 6-13, 15-17. 
“ gigas G. M. Thompson, p. 96, pi. IX, figs. 8-10. 
“ pectinatus Herrick, p. 499. pi. VII, figs. 25 and 28. 
“ Thomasi Cragin, p. 3, pi. Ill, figs. 1-13. 
“ “ Herrick, p. 151, pi. U, figs. 4, 5, 7 and 8. 
“ navus Herrick, p. 152. 
“ pulchellus Daday, p. 220. 
“ Entzii Daday, p..221, pi. I, figs. 1-6. 
“ pulchellus Yosseler, p. 194, pi. Y, figs. 19-29. 
“ “ Sostaric, p. 66, pi. I, figs. 8 and 9. 
“ “ Lande, p. 50, pi. XXI, figs. 146-155. 
“ “ Thallwitz, p. 79. 
“ Thomasi Forbes, p. 707, pi. II, fig. 8. 
“ “ Brady, p. 14, pi. YI, figs. 1-4. 
“ bicuspidatus Schmeil, p. 27. 
“ “ Richard, p. 229, pi. YI, fig. 6. 
“ “ Schmeil, p. 75, pi. II, figs. 1-3. 
