436 Wisconsin Academy of Sciences, Arts, and Letters. 
eral dilatations are situated at the distal third of the segment, 
and each lobe bears two small spines. The second segment is 
very short, and is nearly concealed by the first. The third seg¬ 
ment and the furca are about equal in length. The furcal rami 
are ciliate on both the inner and outer margins. 
The antennae are 25-segmented and extend beyond the furcal 
rami. The right antenna of the male is much swollen anterior 
to the geniculating joint; the antepenultimate segment is pro¬ 
duced on its distal end into a short, blunt process, which makes 
very nearly a right angle with the longitudinal axis of the seg¬ 
ment. 
In the female fifth feet, each of the first basal segments is 
armed on the posterior surface with a very strong tooth-like pro¬ 
jection in place of the customary spine. The lateral hair of 
the second basal segment is rather stout. The length of the 
first segment of the exopodite is twice its breadth. The hook 
of the second segment is strongly curved, and is denticulate on 
its inner margin. The third segment is represented by two 
spines; these spines are unusually long. The endopodite is 
slender and somewhat longer than the first segment of the ex¬ 
opodite. Its tip is setose, and armed on the inner side with 
two long, slender spines. 
In the fifth feet of the male, each of the first basal segments 
is armed on its posterior surface with a strong tooth-like process 
in addition to the customary spines. The second basal segment 
of the right foot is longer than broad. On the posterior distal 
surface near the inner margin is a small hyaline process. The 
first segment of the exopodite is quadrate; it is prolonged 
slightly on its outer distal angle, and on its posterior surface 
near the inner margin bears a broad quadrate hyaline process, 
whose length nearly equals that of the segment. The second 
segment of the exopodite is twice the length of the first, is broad 
at the proximal end, and narrow at the distal end. The proximal 
end is nearly three times as broad as the distal. The lateral spine 
is situated at the proximal third, is long, strongly curved, and 
serrulate on its inner margin; its length about equals the length 
of the segment. The terminal hook is as long as the rest of the 
right foot. It is slender, strongly curved, slightly angular, and 
