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 parens being comparatively rare. 



CYCLOPS BICUSPIDATUS Claus. 



Plate LXXIII, figs. 1-11; Plate LXXIX, fig. 11. 



1857a. Cyclops bicuspidatus Claus, p. 209, pi. XI, figs. 6 and 7. 



1863. " " " , p. 101. 



1863. " pulchellus Sars, p. 246. 



1870. " bicuspidatus Heller, p. 71. 



1872. " " Fric, p. 221, fig. 16. 



1875. " odessanus Schmankewitsch. 



1876a. " bicuspidatus Hoek, p. 17, pi. I. figs. 7-11. 



1880. 



1880a. " helgolandicus Rehberg, p. 64, pi. IV, fig. 5. 



1882 

 1882 

 1882. 

 1883 

 1883 

 1883, 

 1884 

 1884, 

 1885. 

 1885. 

 1886 

 1888, 

 1890, 

 1890 

 1891 

 1891 

 1891 

 1891 

 1892 



pulchellus Rehberg, p. 54i 



pulchellus Vejdowsky, p. 63, pi. VII, figs. 11 and 12. 

 Thomasi Forbes, p. 619, pi. IX, figs. 10, 11 and 16. 

 navus Herrick, p. 229, pi. V, 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. 

 pulcliellus Daday, p. 220. 

 Entzii Daday, p. 221, pi. I, figs. 1-6. 

 pulchellus Vosseler, p. 194, pi. V, figs. 19-29. 

 " Sostaric, p. 66, pi. I, figs. 8 and 9. 

 Lande, p. 50, pi. XXI, figs. 140-155. 

 Thallwitz, p. 79. 

 Thomasi Forbes, p. 707, pi. II. fig. 8. 

 " Brady, p. 14, pi. VI, figs. 1-4. 

 bicuspidatus Schmeil, p. 27. 



Richard, p. 229, pi. VI, fig. 6. 

 Schmeil, p. 75, pi. II, figs. 1-3. 



