468 Wisconsin Academy of Sciences, Arts, and Letters. 



The first abdominal segment of the female is slender and 

 about once and a half as long as the rest of the abdomen. It 

 is dilated in front and laterally. The lateral expansions are 

 well forward, and are terminated with lateral spines. The sec- 

 ond segment is short, less than one-half the length of the third. 

 The furcal rami are much longer than the third segment, and 

 much wider at the distal than at the proximal end. They are 

 setose on the inner margin. 



The antennae are 25-segmented and slightly exceed in length 

 the furcal rami. The antepenultimate segment of the right an- 

 tenna of the male bears a hook which is considerably shorter 

 than one-half of the penultimate segment. 



The first basal segments of the female fifth feet are armed 

 with small spines. The second basal segments have short lat- 

 eral hairs. The exopodite consists of three segments. The 

 third segment is very small, and is tipped with a spine. There 

 is also a small spine on the distal outer angle of the second seg- 

 ment. The second segment is prolonged into a rather blunt 

 hook which is denticulate on the inner margin. The endopo- 

 dite is shorter than the first segment of the exopodite, and is 

 tipped with small hairs. The two terminal spines are very 

 small. 



The first basal segments of the male fifth feet are armed 

 with prominent spines. The lateral hairs of the second basal 

 segments of both feet are situated near the distal end of the 

 segment. The length and breadth of these segments are about 

 equal, and both are strongly curved on the inner margins. From 

 the middle of the inner margin of the second basal segment of 

 the right foot extends a small quadrangular hyaline lamella. 

 The first segment of the exopodite of the right foot is short, its 

 length and breadth being about equal. On its posterior sur- 

 face are two hyaline shelf -like projections. The second segment 

 is considerably longer than the combined lengths of the second 

 basal segment and the first segment of the exopodite. Its outer 

 margin is strongly curved. The lateral spine is large, strongly 

 curved, and situated about midway of the length of the seg- 

 ment. From near the base of the lateral spine a transverse 



