472 Wisconsin Academy of Sciences, Arts, and Letters. 



erally and in front, and bears a strong- spine on each side. 

 The second segment is short, being only about one-half the 

 length of the third. The third segment and the furcal rami 

 iiic alKuit f(]n:il in lt'iiiLi,tli. "i']\e. fui'cal vanu ai'c ciliatc on both 

 the inner and outer margins. 



The antennae are 25-seginentod, and reach to the end of the 

 furca. The right antenna of the male is much swollen ante- 

 rior to the geniculating joint ; the antepenultimate segment 

 bears a slightly recurved hook considerably less in length than 

 the penultimate seginent. In the female tifth feet, the spines 

 of the first basal segments are pronounced. The first segment 

 of the exopodite is about twice as long as wide. The hook of 

 the second seguient is nearly as long as the first segment, is 

 slightly curved, and is denticulate on the inner margin. The 

 hook has a single fine tooth on the outer margin. There is a 

 small spine at the base of the third segment. The third seg- 

 ment is distinct, and bears two spines of which the inner is the 

 longer. The endopodite is indistinctly two-segmented, and is 

 about one-half the lengih of the first segment of the exopodite. 

 It is setose at tip. 



In the male fifth feet, the spines of the first basal segments 

 are stout. The length of the second basal segment is some- 

 what less than twice its width; it is trapezoidal in form, and 

 wider at the distal end. The lateral hair is situated close to 

 the distal end of the segment. The proximal inner angle is ex- 

 panded into a wing-like process. At a little less than one-half 

 its length, there is on the inner margin a recurved liyaline 

 tooth. On the posterior surface of the segment is a two-headed 

 hyaline process. The first segment of the exopodite is short, 

 its length being only about one-half its width. The outer dis- 

 tal angle is somewhat extended. The segment has a hyaline 

 lamella on its posterior surface, and a small hyaline projection 

 from its posterior distal border. The second segment of the 

 exopodite is between three and four times as long as the first 

 segment. The lateral spine is situated at about four-fifths 

 of its length, is long, nearly straight, and finely denticulate on 

 its inner margin. On the posterior surface of the segment, 



