ENTOMOSTRACA OF MINNESOTA. 201 
line very slender and short, directed dorsad. Abdominal processes 
long, approximate, the first twice as long as the second. Anal spines 
16 to17. Length 1.83 mm. 
Dapnia lacustris Sars. 
Very similar to D. aquilina and to D. rosea. The head is depressed 
and excavated behind the eye, the beak projecting ventrad below the 
level of the front. The eye retreats from the front and is large. 
The shell is oval and the spine is straight, springing from the mid- 
dle of the caudal margin. The abdominal processes are discrete 
but approximate. Post-abdomen as in D. longispina, with 14 to 16 
teeth. Length 2.21 mm. This is doubtless to be reckoned among the 
varities of D. longispina. 
Daphnia dentata Matile. 
Matile ’90. 
I translate the description, 1. ¢. p. 14. 
Body transparent. Head low and rounded cephalad; its ventral 
margin rather short and concave. Apex of beak directed ventrad 
[nach unten]. Antennal sete three-jointed, the last segment very 
short. Head separated from the thorax uniformly in adult animals 
by a tooth-like projection cephalad. Valves oval, extending into a 
rather short spine which lies somewhat dorsad of the median, longitudi- 
nal axis. Spine and the caudal half of ventral margins of the valves 
spined; dorsal edge without spines. Shell reticulated by regularly 
crossing lines. First two anal processes approximate and of equal 
length. Borders of the anal groove armed on either side with 12 to 14 
spines which diminish gradually in size dorsad, Terminal claws 
without the comb of spines but armed with a continuous series of very 
fine sete; on the convex side two small spines. Eye large, with many 
erystallines; macula nigra point-like. Length 1.20 mm., height 
0.70 mm., height of head 0.25 mm., length of spine 0.11 mm. 
The male is smaller. Antennule somewhat curved; at the free 
end it bears, besides the sensory threads, a flagellum, which is some- 
what curved at the end and dark contoured at the base and is at least 
twice as long at the sensory sete. The lateral seta is situated some- 
what separated from the flagellum on the front (cephalic) margin of 
the antennule. There is the same cervical toothed process seen in the 
female. Abdominal processes absent. Lengtn of male 0.78 mm.; 
height 0.42 mm. 
It would appear that Forbes D. dentifera is the American represen- 
tative of this species. It differs in having the cervical process much 
