ee 
ENTOMOSTRACA OF MINNESOTA. 199 
abdomen small. Anal teeth 12 to 14. Claws with a series of fine 
Sete. Length 2.18mm. In the male the lower margin of the head is 
excavated and the flagellum of the antennules short and straight. 
Daphnia longispina Mueller. 
Mueller 1785; Straus-Durckheim ’19-’20; Baird ’50 (pulex var. longispina); Leydig ’60; 
Sars ’61, and ’64 (affinis); Mueller ’68; Plateau ’70; Lund ’70-’71; Kurz ’74; Hu- 
dendorff ’76; Hellich ’77; Lutz ’78 and ’79; Herrick ’84; Elymann ’87; Walter 
788; Daday ’88; Matile ’90. 
A slender species of moderate size and transparent. Head not so 
deep as the body, from which it is not separated by a depression, 
slightly concave behind the eye. Beak long and directed caudo-ven- 
trad. Hye large, near the margin. Shell oval; spine long, situated 
above the middle line and curved upward. 
Two largest abdominal processes both directed cephalad and some- 
what united. Anal spines 10 to 12. Claws with a series of fine setze 
and two spines on the convex aspect. Length 2.0 to 2.5 mm. 
Flagellum of the male antennule hardly longer than the sensory 
setee. The young have three teeth above as in D. minnehaha. There 
is a great deal of diversity of opinion as to the value of this name. 
Not that there is any doubt of the existence of a widely dstri buted 
form which in general is that intended by Leydig and others, but the 
variation is so great that the possibility remains that more than one 
species is included under the one title. 
P. E. Mueller recognizes two varieties depending chiefly upon the 
length of the spine. 
* Daphnia minnesotensis sp. n. 
PLATE L, Fias. 10-12. 
Herrick ’84 (rosea.) 
The later descriptions of D. rosea leave no doubt that this is a 
distinct species. The abdominal processes are somewhat united at 
the base instead of ‘‘manifeste discretis,’’ and the first is much longer. 
In many respects the species is near D. longispina. The original de- 
scription is given: ‘‘In form very like D. longispina, this species, 
which is the only representative of this smooth-clawed, unkeeled 
group yet found in America, might perhaps be appropriately united 
with that species. 
‘“Body oval, moderately ventricose; head of moderate size, lower 
margin nearly straight; eye situated in the anterior prominence. The 
beak is not very prominent. The upper outline of the head is slightly 
concave above the eye or rather less convex. The head is separated 
