82 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. 
‘‘Body small, eye single, near the anterior margin of the shield. 
Antenne large, and as long as in the preceding genus (Cyclops), and 
has the same motions in the water. Abdomen terminating in two 
styles, each with three sets; last or three last joints. Ovaries none; 
legs spiny.”’ 
What is meant by the ‘‘brush”’ fails to appear, unless the speci- 
‘mens were ornamented with some parasitic plants or animals. The 
three sete of the caudal stylets and long antennz will place this form 
in no American genus save Hpischura. But even this statement of 
Pickering may be held doubtful. 
* Epischura lacustris Forbes. 
PLATE XIII, Fie. 1d. 
Forbes ’82; Herrick ’84 and ’87; De Guerne and Richard ’89. 
‘The second segment of the abdomen of the male is twice as long 
as the first, and produced to the right as a large, elongate, triangular 
process, somewhat hooked backwards at the tip. The third segment 
is similarly produced, but rounded and expanded at the tip, which is 
roughened before and behind. 
‘‘Hrom the right side of the fourth segment arises a stout process | 
bearing at its apex a hatchet-shaped plate with seven broad obtuse 
serratures on its anterior margin. This process is roughened behind, 
where it is opposed to the concave side of the left ramus of the furea. 
From the same side of the fifth segment, a short flattened plate, of a 
spatulate or paddle-like form, extends forward above or beyond the 
toothed process just mentioned. 
‘“‘The antenne are 25-jointed, and reach to the second segment of the 
abdomen. There are especially prominent sensory hairs on the first 
and third joints, borne at the tips of long spines. The antennules 
are short, the ramus apparently but three-jointed, the short, median 
joints common in this appendage being only obscurely indicated. The 
mandible has but seven teeth, the first simple and acute, separated 
from the second by an interval about equal to the second and third, 
the second to the sixth bifid, the seventh entire and acute. The usual 
plumose bristle is replaced by a sharp, simple spine. 
‘¢The outer ramus of the fourth pair of legs has two teeth at the outer 
tip of each of the two basal joints. The terminal joint of this ramus 
is armed as follows: a short simple spine at middle of outer margin 
and another at the distal outer angle; a single and long terminal seta, 
strongly and sharply toothed externally and plumose within, and four 
long plumose sete attached to the inner margin. 
‘The left leg of the fifth pair in the male, viewed from behind, has 
the basal joint very large, broader than long, with the inner inferior 
angle produced downwards as a long, stout, curved process or arm as 
