290 
Birge—Notes on Gladocera. 
B. On new or rare species of Cladocerct chiefly from Northern 
Wisconsin. 
Moina affinis, sp. nov. 
Plate X, Figures 1, 3, 5, 7, 8, 12, 13, 14. 
Female.—The head closely resembles that of M. rectirostris ,. 
Jur., being somewhat rounded anteriorly, having a deep de¬ 
pression above the eye, and being without an angle on the ven¬ 
tral margin posterior to the antennules. As seen from above/ 
the head is rather long and narrow and shows the supraocular 
depression very distinctly The outline of the sides of the 
head is slightly concave in the middle and the sides round over 
evenly into the anterior margin. The valves are fringed on the' 
margin with setae- more closely set than in M. rectirostris , and 
are marked by transverse, anastomosing lines, giving an ap¬ 
pearance . to the shell somewhat like that of a Simocephalus. 
These markings can 'be seen when the shell is examined un¬ 
covered and without water, and also, by careful manipulation, 
under a cover-glass. These striae resemble those of M. Lillje- 
borgii , Schdl. as figured by Lilljeborg, (’53,* p. 38, pi. II, f. 4f.),. 
and still more closely those of M. propinqua , Sars, as described 
and figured by him. (’85, p. 31, pi. VI, f. 1.) 
The structure of the legs agrees exactly with that of M. rec¬ 
tirostris t as described by Gruber and Weismann. (’77, p. 70-72.) 
The post-abdomen has a relatively long post-anal portion,, 
which is armed with 9-11 serrate teeth and a bident longer 
than the adjacent tooth. The caudal claws have a pecten of 
12-15 teeth at the base and are denticulate. 
The ephippium contains one egg whose long axis is parallel 
to that of the body. The ephippium is densely reticulated over 
its entire surface. 
The antennules are of moderate size, being apparently some¬ 
what smaller than the figures of M. rectirostris would indicate 
for that species. The usual anterior sense-hair is placed a, 
* For full titles of papers, see the list at the end of this article. 
