196 Marsh—Cyclopidce and Calanidce of Wisconsin. 
It is quite common in the summer and fall months. As I 
have found it, it has been of a brownish red color, much like 
D. sanguineus , with purple tipped antennae and caudal setae. 
D. Kentuckyensis Chambers, is probably identical with lepto- 
pus , although the imperfect figures make it impossible to decide 
with certainty. 
Diaptomus pallidus Herrick. 
Plate III. Figs. 6, 7 and 9. 
1879. D. pallidus , Herrick (18a) P- 91, pi. II, a-d. 
1884. “ I “ (26) p. 142, pi. Q, fig. 17. 
1889. “ “ DeG-uerne and Richard (32) p. 62, fig. 17. 
A small, slender species. Cephalothorax elongated oval,, 
widest at about the middle; the last segment is armed with 
two minute lateral spines. 
The first abdominal segment of the female is as long as the 
remaining part of the abdomen, and is dilated laterally. The 
second abdominal segment is shorter than the third. The 
furcal joints are about twice as long as broad. 
The antennae reach beyond the furca. The right antenna of 
the male is swollen anterior to the geniculating joint; it bears 
no appendage on the antepenultimate joint. 
The outer ramus of the fifth foot of the female is two-jointed;; 
the third joint is represented by two blunt spines. The inner 
ramus is one-jointed, equaling in length the first joint of the 
outer ramus; it is armed with a short spine at tip, and two 
larger ones on inner margin of tip; the inner surface of the 
tip is covered with short hairs. 
The fifth feet of the male are slender, with the basal joints 
nearly equal in length. The first joint of the outer ramus of 
the right foot is a little shorter than the basal joint. The 
second joint is nearly twice as long as the first; on its inner 
margin at about a third of its length is a short spine-like pro- 
jection, the lateral spine is slender, situated near the outer 
end of the joint. The terminal hook is falciform, but not with. 
