442 Wisconsin Academy of Sciences t Arts, and Letters. 
In the male fifth feet, the spines of the first basal segments 
are prominent and acute. The second basal segment of the 
right foot is twice as long as broad. The lateral hair is situat¬ 
ed at the beginning of the distal third. The first segment of 
the exopodite is quadrate, and bears a hyaline process on the 
inner distal angle. The second segment is strongly curved and 
equals in length the first basal segment. The lateral spine is 
straight and rather small and situated just distad of the mid¬ 
dle. The terminal hook is slender, slightly curved, and equal 
in length to the rest of the foot with the exception of the first 
basal segment. It is denticulate on the inner margin. The 
endopodite is small, much less in length than the first segment 
of the exopodite. It is ordinarily pointed, but in some cases 
the tip is rounded. The left foot reaches to the end of the 
first segment of the right exopodite. The second basal seg¬ 
ment is as long as wide, and strongly convex on the inner mar¬ 
gin. The lateral hair is situated near the distal end. The 
first segment of the exopodite is much longer than wide 
and setose on the inner margin. The second segment is about 
one-half the length of the first, and the inner surface is a con¬ 
vex setose pad. The segment is terminated with two digiti- 
form processes, of which the outer is the longer. The endopo¬ 
dite is long and slender, reaching to the middle of the second 
segment of the exopodite. It is either one-segmented or in¬ 
distinctly two-segmented. The tip is distinctly setose. 
Length, accordng to Poppe: female, 1 mm.; male, 1.5 mm. 
Length, according to Lilljeborg: female, 1.9 mm.; male, 1.8 
mm. 
My specimens averaged: female, 1.258 mm.; male, 1.15 mm. 
The original description by Poppe was from material col¬ 
lected at Summit lake in the Pocky mountains, at a height of 
5300 feet.' Lilljeborg’s material was from Centerville, near 
Fresno, California. 
The material from which my drawings were made was col¬ 
lected by the U. S. Fish Commission in Alturas lake, Idaho. 
Probably, then, it is widely distributed in the mountain re¬ 
gion of the West. 
