1082 Wisconsin Academy of Sciences, Arts, and Letters. 



1891. Cyclops Leuckarti Schmeil, p. 25. 



1891. " " Richard, p. 230, pi. VI, fig. 20. 



1891. " edax Forbes, p. 709, pi. Ill, fig. 15, pi. IV. figs. 1-20. 



1891. " Scourfeldi Brady, p. 10, pi. IV, figs. 1-8. 



1892. " Leuckarti Schmeil, p. 57, pi. Ill, figs. 1-8. 



1892. " simplex Lande, p. 101. 



1893. " Leuckarti Marsh, p. 209, pi. IV, fig. 17, pi. V. figs. 2-6. 

 1895. " Leuckarti Herrick and Turner, p. 96, pi. XVI, Hgs. 1-11, pi. 



XVIII, fig. 1, a-j, pi. XXIV, figs. 2-6. 



1895. " Leuckarti Marsh, p. 15, pi. VII, fig. 15. 



1897. " Leuckarti Forbes, p. 31, pi. VIII, figs. 1-3. 



1897. " edax Forbes, p. 33, pi. IX, fig. 1-3. 



1897, " Leuckarti Scott, p. 322, pi. IX, figs. 23-25. 



1897. " " Steuer, p. 32. 



1898. " " Brewer, p. 131. 



1900. " " Burckhardt, p. 040. 



1901. " " Lilljeborg, p. 35, pi. II, figs. 28-29. 

 1903. " " Graeter, p. 509, pi. 15, figs. 26 and 30. 

 1905. " " Van Douwe, p. 681. 



1909. " pulchellus Byrnes, p. 24, pi. X, figs. 1-3. 



A conspicuously slender species. The length of the cephalo- 

 thorax compares with that of the abdomen as 7 to 4. The- 

 breadth of the cephalothorax is about one-half its length. The 

 elongated oval form of the cephalothorax is a characteristic pe- 

 culiarity of this species. The segments of the cephalothorax 

 do not project markedly on the sides. 



The abdomen (PI. LXXIY, fig. 3) is slender. The first seg- 

 ment is equal in length to the remaining segments, and its an- 

 terior end is only slightly larger than the posterior. The suc- 

 ceeding segments are all of about the same length. The last 

 segment is armed posteriorly with a row of spines. 



The furcal rami equal in length the two preceding segments.. 

 Generally the inner margins are ciliated, although this is not 

 always the case. The lateral seta is so situated as to divide 

 the furca in the ratio of three to two. The terminal setae 

 vary in their length ; of the four, the inner is more than twice 

 as long as the outer, the outer is commonly not far from the 

 length of the furca. 



The first antennae are 17-segmented and reach to the fourth 

 cephalothoracic segment. The twelfth segment bears a sensory 

 club. Upon the sixteenth and seventeenth segments is a 



