80 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 



angular and armed with fine serrulations on its inner margin. The 

 inner ramus is one-jointed, equaling in length the first joint of the 

 outer ramus. 



''The left fifth foot of the male reaches slightly beyond the first joint 

 of the outer ramus of the right. The basal joint is quadrangular, con- 

 siderably shorter than the right basal joint. The first joint of the 

 outer ramus is about twice as long as broad. The second joint is 

 slightly longer than the first joint; it is expanded at base, where it is 

 armed with fine hairs, and terminates in a finger like process bearing 

 a falciform spine. The inner ramus extends to about one half the 

 length of the second joint. Length of female, 1.5 mm.; male, 1.3 mm. 



"The material in which this species was found was collected by 

 Professor E. A. Birge at New Lisbon, Wisconsin, and only a few indi- 

 viduals were found. I have expected to find it in the collections from 

 other Wisconsin localities; but so far my search has been without suc- 

 cess. It is a clearl}^ marked species resembling the European D. gracilis 

 Sars more closely than does any other described American species. The 

 characters of the fifth feet, however, separate it from the European 

 form. 



"I have taken the liberty of naming this species in honor of Profes- 

 sor Birge, to whose kind assistance and encouragement I have been 

 greatly indebted." 



GENUS BROTEAS Loven. 1845. 

 Thorax five-jointed. First antennae multiarticulate; second pair 

 biramose. Swimming feet four pairs, bi-ramose, outer ramus three- 

 jointed, inner two jointed; fifth feet dissimilar in the sexes. The third 

 pair of maxillipeds falciform. Abdomen of the male six-jointed, in 

 the female two jointed. The single known species, B. falcifer Loven 

 (Plate X, Fig. 16), a large slender form (4.0 mm. long), occurs in salt 

 pans near Port ISTatal. 



GENUS HETEROCOPE Sars. 1863. 



Cephalothorax six-jointed; last thoracic segment more or less divari- 

 cate alike in the two sexes. Abdomen of female three-jointed, of the 

 male five-jointed. Caudal stylets; larger setsB three. Antenna 25- 

 jointed; in the male right antenna a geniculatiug joint between seg- 

 ments 18 and 19, the six preceding somewhat tumid. Swimming feet 

 four pairs, of which the outer rami three-jointed, the inner one- 

 jointed. Fifth feet of female simple, three jointed, those of the male 

 dissimilar; the left cheliform. Abdomen of the male symmetrical. 



Reterocope is obviously the eastern homologue of Upischura. 



The three species of this genus may be tabulated thus, following 

 De Guerne and Eichard: 



