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 to 17. Length 1.83 mm. 



Dapnia lacustrls Sars. 



Very similar to T). aquiUna 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. 



Daplinia deiitata Matile. 

 Matile '90. 



I translate the description, 1. c. p. 14. 



Body transparent. Head low and rounded cephalad; its ventral 

 margin rather short and concave. Apex of beak directed ventrad 

 [nach unten]. Antennal sette 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 

 rathershort 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 sette; on the convex side two small spines. Eye large, with many 

 crystallines; 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 setse. 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. Length of male 0.78 mm.; 

 height 0.42 mm. 



It would appear that Forbes I), denfifera is the American represen- 

 tative of this species. It differs in having the cervical process much 



