158 
IOWA ACADEMY OP SCIENCES. 
Daphnia pulex var. pulicaria — Was found in small numbers in 
a prairie slough near Portage la Prairie. 
Simoceplialus daplinoides (?). — The body is robust, with great- 
est height a little behind the middle. The head is rounded in 
front and has no spines. Lower margin of the head is slightly 
concave, straight, or even slightly convex to the base of the 
short beak which may project at nearly a right angle to the 
lower margin of the head. The head is separated from the 
body by only a very slight depression. Depth of the head in 
one specimen is .77 mm., length from the posterior margin of 
the base of the antennae .52 mm. The head has a daphnia-like 
appearance. The ventral margin of the shell has few very 
short blunt teeth. The posterior margin from short blunt pos- 
terior spine toward dorsal margin has teeth better developed 
than those on the ventral margin. The dorsal margin teeth 
continue forward a shore distance. The posterior spine is very 
short, blunt, armed with short teeth and is situated little above 
the middle of the posterior margin. 
The eye is of moderate size, situated near the front of the 
head, or at a short distance from the front, and at a distance 
from the lower margin equalling one-half the diameter of eye, 
or at a distance slightly greater than diameter. Pigment fleck 
is irregular in shape; elongated, rhomboidal and oval forms 
were seen, Pigment fleck is small, situated near the posterior 
margin of the head. 
Specimens measured vary in length from 2. 04 mm. to 2. 53 mm. 
in depth from 1.20 mm. to 2.04 mm. 
The description of S. daphnoides as given by Herrick in 
American Naturalist, May, 1883, and in Entomostraca of Min- 
nesota, is rather brief. Herrick states that the form is found 
only south of the Tennessee river; but a comparison of speci- 
mens taken in Manitoba, with the original drawings and brief 
description in the American Naturalist, makes it probable the 
form is found even in that northern province. 
Lilljeborg’s ‘‘Crustaceis” published in 1853, gives drawings 
of S. vetulus, with the lower margin of the head as yearly 
straight as in the figures by Herrick, and the general outline of 
the body almost as daphnia-like in appearance. 
Eylmann in the ‘ ‘ Berichte der Naturforschenden Gesellschaf t 
zu Freiburg” Zweiter Band, Drittes Hefc, published in 1886, 
figures the lower margin of the head of S. vetulus straight to 
the short beak, and the body with greatest height at the middle. 
