Marsh—North American Species of Cyclops. 
1079 
1892. 
.1893. 
1893. 
1893. 
1895. 
1895. 
1895. 
1895. 
1895. 
1897. 
1897. 
1898. 
1898. 
1901. 
1903. 
1909. 
Cyclops pulchellus Lande, p. 161. 
“ “ Marsh, p. 207, pi. IY, figs. 18 and 19. 
“ minnilus Forbes, p. 247. 
“ serratus Forbes, p. 247. 
“ pulchellus Herrick and Turner, p. 101, pi. XXVII, figs. 4 
and 5, pi. XXVIII, figs. 5-8. 
“ pulchellus var. navus Herrick and Turner, p. 102. 
“ • minnilus Herrick and Turner, p. 103. 
“ Forbesi Herrick and Turner, p. 104. 
“ pulchellus Marsh, p. 15, pi. VII, fig. 14. 
“ bicuspidatus Forbes E. B., p. 44, pi. XII, figs. 1-4. 
“ bicuspidatus Steuer, p. 5, pi. Ill, fig. 1. 
“ pulchellus Brewer, p. 133. 
“ navus Brewer, p. 132. 
“ bicuspidatus Lilljeborg, p. 11, pi. I, figs. 12-17, pi. II, fig. 1. 
“ “ Graeter, p. 528, pi. XV, figs. 23 and 32. 
“ bicuspidatus Byrnes, p. 25, pi. X, figs. 4-7. 
The cephalothorax is elongate oval, its length being con¬ 
siderably more than twice its breadth. Seen from above the 
lateral angles of the segments back of the first are somewhat 
extended backward. The cephalothorax is rather more than 
twice as long as the abdomen exclusive of the furcal rami. 
The first abdominal segment is only slightly narrower than 
the last cephalothoracic segment, and its anterior part is con¬ 
siderably wider than the posterior. The first abdominal seg¬ 
ment about equals in length the three following. The posterior 
margins of the abdominal segments are more or less clearly 
marked with serrations, with the exception of the last seg¬ 
ment which is armed with small spines. 
The furcal rami (PI. LXXIII, figs. 3, 7 and 8, pi. LXXIX, 
fig. 11) vary greatly in their length. The length may exceed 
little more than twice the breadth, or it may reach to six or eight 
times the breadth. The inner margins of the rami are ordi¬ 
narily ciliate, although this is not an invariable characteristic. 
At about one-quarter of the distance from the proximal end is 
a row of small spines on the lateral margin. These spine® 
are almost invariably present on the forms with elongated 
furcal rami but are not found on those with the very short 
rami. The lateral seta, which is • surrounded with minute 
spines, is placed at about two-thirds of the length of the ramus. 
Of the terminal setae, only the inner ones are elongated. 
