162 
IOWA ACADEMY OP SCIENCES. 
lower margin has a few long hairs anteriorly which are followed 
by a series of teeth, and in the concave part a 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 bris- 
tles, 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 hex- 
agonal reticulations are seen upon the shell of the embryo yet 
in the brood sac. In several sexually 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 reported 
from Iowa. Although reported from Georgia it seems to be 
more commonly found in the north. 
A NEW SPECIES OP DAPHNIA,^ AND BRIEF NOTES 
ON OTHER CLADOCERA OF IOWA. 
BY L, S. ROSS. 
A few collections taken from West and Eist Okoboji Lakes 
and Spirit lake in June, and from the sloughs of the Des Moines 
river in the fall of 1896, have added six more species to the list 
of Cladocera in tbe state, as given in the “Proceedings” of the 
Academy for 1895. Five of the species are common to the 
country, and one is an hitherto undescribed species of Daphnia. 
A few individuals of a form of the difficult genus Bosmina were 
found which may be the young of Bosmina longirostris, O. F. 
Muller. If not the young of this species then seven instead of 
six species will be added to the list. 
The species taken the past summer and fall not reported in 
the “Preliminary Notes” are; 
Daphnia pulex De Geer. 
Daphnia hybus n. sp. 
Bosmina longirostris O. P. Muller. 
