430 Wisconsin Academy cf Sciences, Arts , and Letters. 
segment. The third segment is represented by two spines, of 
which the outer is the longer. The endopodite is slender, ter¬ 
minating in a blunt point. It is a little longer than the first 
segment of the exopodite. It is setose at tip, and has two rather 
long terminal spines. 
The spines of the first basal segments of the male fifth feet 
are small and acute. The second basal segment of the right 
foot is twice as long as broad. The lateral hair is situated at 
the beginning of the distal third. The first segment of the ex¬ 
opodite is broader than long, the proximal end being much 
narrower than the distal. The inner distal angle bears a small 
hyaline appendage. The second segment equals in length the 
combined length of the second basal segment and the first seg¬ 
ment of the exopodite. The segment is widest at the end of the 
proximal third, and from this point springs the lateral spine;, 
this is rather long, acute, with a rather abrupt curvature just 
above the base. The terminal hook is slender, falciform with 
a symmetrical curvature, and considerably exceeds in length 
the rest of the exopodite. It is minutely denticulate on the 
inner margin. The endopodite is slender, equaling or exceed¬ 
ing in length the first segment of the exopodite. The left fifth 
foot extends to about the end of the first segment of the exopo¬ 
dite. The second basal segment is about half the length of the 
corresponding segment of the right foot. The lateral hair is 
long and slender, and situated at the beginning of the distal 
third. The first segment of the exopodite equals the second 
basal segment in length; its length exceeds its width by about 
one-half. The second segment equals in length the first, but 
is much narrower; it is terminated by two small finger-like 
processes. Both segments of the exopodite are setose on the 
inner margin. The endopodite is long, slender, curved, and 
reaches to about the middle of the second segment of the exopo¬ 
dite. 
Length of female, 0.97 mm. Length of male, 0.89 mm. 
The original description was from material collected by Pro¬ 
fessor Birge at Ashland, on Lake Superior. It occurs in all 
the Great Lakes, and I have found it in Michigan in Pine lake 
