ENTOMOSTRACA OF MINNESOTA. 109 
THIRD Foor. 
ex. 2 spines. ex. 1 seta. 
Outer ramus ap. 1 spine, 1 seta. Inner ramus 4 ap. 2 spines. 
in. 4 sete. in. 1 spine, 2 sete. 
FourTH Foot. 
ex. 2 spines. ex. 1 seta. 
Outer ramus jap. 1 spine, 1 seta. Inner ramus jap. 2 spines. 
in. 4 sete. in, ~ 2 setz. 
The fifth foot is obscurely three-jointed, the second joint bearing a. 
short spine and the terminal joint two spines of varying length. The 
caudal stylets are once and a half as long as the last segment, and are 
peculiarly excavated for more than the caudal one-third, beginning at 
the point where the lateral spine is situated. The outer apical seta is 
short, the median sete are rather short while the inner seta is nearly 
as long as the outer median. AI] these setie are pectinate. The recep- 
taculum seminis is elongate oval. The antenna of the male is divisi- 
ble into five regions, the third being formed by the thickening and 
union of four or more segments. Color violet or purplish red. 
* Cyclops capilliferus Forbes. 
PLatss VI, Fra. 13; XXVIII, Fras. 1-4. 
Forbes 793. 
This is a symmetrical, compact Cyclops, with the cephalothorax 
closely articulated, widest in the middle, and the sides regularly con- 
vex, with the abdomen narrow and slender, with three well developed 
caudal sets, and 16 jointed antennze bearing several very long sete. 
The abdomen, with caudal furca, is contained a little less than 
twice in the cephalothorax, and the breadth of the latter is just half 
its length. First segment very long, five times the length of the sec- 
ond; second and third equal; the fourth very short, on the median 
line semicircularly excavate behind. The abdominal segments in the 
female diminish regularly in length from first to last. The caudal 
rami are twice the length of the last segment and one fourth as broad 
as long. The lateral seta is placed a trifle beyond the middle of the 
ramus; the outer terminal seta is a short, naked spine; the other three 
well developed and plumose. The inner and outer of these are of 
nearly equal length, the latter a little longer, the middle one much 
the longest one of the group. Antenna moderate, reaching about to 
the middle of the second segment of the cephalothorax. Sixteen- 
jointed in all adult females, and further especially distinguished by 
the presence of very long flexible sete upon the first, third, tenth and 
fourteenth segments. Terminal sete likewise very long. The seta 
borne by the first segment extends to the twelfth; that of the third 
reaches to the fourteenth; that upon the tenth segment extends to the 
