[1915 
JUDAY AND MUTTKOWSKI I ALASKAN EnTOMOSTRACA 
27 
esses of the thorax and the lateral spines of the first abdominal 
segment of the female. These spines, however, are located in 
the basal third of the abdominal segment of theeli, about in the 
middle in pribilofensis; the lobate processes of the thorax are 
more acuminate in adult pribilofensis. The fifth feet of the female 
of theeli show a terminal segment which is as broad at the base 
as the preceding segment, with two spines at the base, one of the 
spines with two joints; in addition the endopodite is two-seg- 
mented. In pribilofensis the terminal segment is long and slender, 
with three spines at the base, none of them jointed; the endop- 
odite shows no indication of bisegmentation. 
In the male fifth feet of theeli the second segment of the right 
foot bears a medial internal tubercle, the endopodite is as long, 
or longer, as the first joint of the exopodite, one-third the width 
of this joint; the second segment of the left foot is oblong, with 
a small internal basal tubercle. In pribilofensis no tubercle is 
found on the second segment of the right foot, the endopodite 
is small, acuminate, the second segment of the left foot bears 
an internal median notch, giving a bilobate appearance. 
This new form is represented in our material in large numbers 
Heterocope septentrionalis nov. sp. 
$ . — The body is robust and broadly oval in outline, the widest portion 
is a little anterior to the middle and is nearly half the length. The urosome 
and metasome are about equal in length. The first or genital segment of 
the abdomen is about as long as the two succeeding segments (fig. 4, C). 
The posterior portion of the genital area bears two conspicuous processes 
which are curved and trilobate on their outer margin (fig. 4, D and E ). The 
second and third abdominal segments are about equal in length. The 
caudal rami are about one and a half times as long as broad and ciliate on 
the inner margin. At the outer end each ramus bears three plumose setae 
and two bristle-like appendages which are about as long as the rami them- 
selves. One of these bristles is situated at the outer distal angle of each 
ramus and the other on the ventral surface near the inner angle. 
The reflexed antennae extend about to the end of the genital segment. 
The swimming appendages are all symmetrical. The first pair bears 
only plumose setae while the next three bear spines instead of setae on the 
outer margin of the exopodite. The terminal segment of the fifth pair of 
feet bears four toothed processes on its inner margin, two fairly large spines 
on its outer margin, and two apical spines, one of which is small and the 
other long and spinose (fig. 4, B). 
c f. — The male is somewhat smaller than the female. The abdomen is 
slenderer than that of the female and consists of five segments instead of 
three of which the fourth is the smallest (fig. 4, F ). 
