ENTOMOSTEACA OF MINNESOTA. 191 



bles and the front of the head, and about midway between the tip of 

 the beak and the dorsal surface of the head. Pigment speck very 

 small, less than half the diameter of a lense of the eye, and placed 

 midway between the eye and the posterior margin of the head. The 

 latter concave, the beak extended backward and applied against the 

 m'l.rgin of the shell. Swimming antennae reaching the middle of the 

 shell, their hairs moderately robust, the first segment not longer than 

 the second. No emargination separating head from body, but the 

 dorsal surface very slightly sinuate there. Abdominal processes all 

 distinct, anterior much the longest. Caudal claw with accessory 

 teeth, about six in number, the three proximal the largest. Anal 

 spines about ten. Posterior spine of the shell given off from the 

 middle of the valves, in the adult female a third to a half as long as 

 the valve. Shell moderately coarsely marked in quadrangular areas, 

 the lower and dorsal margins spinulose from the middle backwards. 

 Length 2.0 mm., depth 1.0 mm. Heart Lake, Yellowstone Park." 



Dapliuia g'ibbosa Hellich. 

 Hellich '74 and '77; Elymann '87. 



Body large, very high. Head depressed, ventral margin strongly 

 concave. Eye large, with few crystallines. Antenuse long, scaly. An 

 obvious depression separates head and body. Spine short, above the 

 middle. Abdominal processes united. Anal teeth 17 to 19, dimin- 

 ishing dorsad. Claws with a comb of teeth. Color reddish. Length 

 2.01 mm. 



Dapbnia ovata Sars. 



"Capijt a latere visum ante oculum fere angulatum, margine inferiore leviter con 

 ■cavo in rostrum longum apicem versus attenuatum, extremitate tenuissima exeunte- 

 spura visum ut in D. pennata cordiforme. Testa cetera a latere visa ovata, margine 

 superiore et inferiore in femina adulta fere requaes arcuatis, postice in medio spinam 

 formans brevissimam vel omnino obsoletam. Processus anteriores duo abdominis dis- 

 juncti. Margo posterior postabdominis in medio sinuatus, utrinque aculeis 20-22 

 armatus. Color albido — flavescens velviresceus. Longit. circitSmm." 



No one besides Sars seems to have seen this species. We suspect 

 it is simply D. scluefferi. 



Daphnia obtusa Kurz. 



Lilljeborg '53(pulex); Kurz '74; Hellich '77; Elymann '87; Daday '88. 



Head short, front rounded, veutral margin slightly sinuate, beak 

 short, acute turned caudad. Eye remote from the margin of head. 

 Orest absent. Body oval, margins convex, spine nearly absent. Post- 



