1897.] Some Manitoba Cladocera. 308 
and slender, resembling that of Camptocercus, and is notched 
at the distal extremity ; it has two rows of fine teeth and some 
fine scales above them. The terminal claws are long, slender, 
with a basal spine in the middle, and are serrated. The an- 
tennules are long and slender, but do not reach to the end of 
the rostrum. They have each a flagellum and sense hairs. 
The antennz are small and have eight (3?!) setee and two (its 
spines. The labrum resembles that of A. leucocephalus, but is 
slightly prolonged at the apex. The intestine, cecum, and 
color resemble those of Acroperus. There is a trace of a keel 
present on the back.” f 
Herrick’s statement, in part, is as follows: “The specimens 
seen in Minnesota resemble this species, (A. latissima var. 
media) very nearly, apparently, but there are some differences. 
The terminal claw has an increasing series of spines to the 
middle; there seems to be no lateral row of scales beside the 
anal teeth ; the abdomen is rather broad at the base and nar- 
rows toward the end. The shell is not square behind. The 
lower margin has a few long hairs anteriorly which are followed 
by a series of teeth, and in the concave parta somewhat longer 
set to a point just before the lower curved angle.” 
In most respects the Manitoba specimens agree more nearly 
with Herrick’s description than with Birge’s. A few points of 
difference are noted. In the Manitoba specimens a few long 
hairs are present on the lower margin anteriorly, then at a little 
distance posteriorly from the hairs are short sharp bristles, 
hardly heavy enough to be called teeth, becoming largest on 
the concave part of the margin. In one specimen the end of 
the abdomen is deeply cleft, the posterior lobe bearing four 
very strong teeth of nearly equal size. 
Herrick says that hexagonal reticulations are seen upon the 
shell of the embryo yet in the brood sac. In several sex- 
ually mature females observed faint reticulations are present, 
more distinctly seen near the ventral margin. 
Polyphemus pediculus: This species was found to be quite 
common in the Portage Plains region. It has not been re- 
ported from Iowa, and Birge says it is not common in south- 
ern Wisconsin. Although reported from Georgia it seems to 
be more commonly found in the north. 
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