North American Centropagidce. 251 



and represented in different sections by different species, is 

 found from Newfoundland on the north and east to Wash- 

 ington on the west, and as far south as central Illinois and 

 Indiana. 



KEY TO THE SPECIES OF EPISCHUBA. 



Based on the Characters of the Female. 



1 (2). Abdomen flexed to the right ; second segment armed 



on the right side with a process. Furcal setae and 

 spines very broad. Fifth leg with last segment twice 

 as long as the first ; last segment armed with seven 

 spines. lacustris. 



2 (1). Abdomen straight; second segment unarmed. Fur- 



cal seta? and spines of ordinary width. 



3 (4). Fifth legs very robust, first segment almost as wide 



as long ; second segment sometimes armed with two 

 spines; third segment armed with six (occasionally 

 seven) spines. nevadensis. 



4 (3). Fifth legs slender, first segment considerably longer 



than wide ; second segment armed with a single small 

 spine ; third segment armed with five (sometimes six) 

 spines. nordenskioldi. 



Based, on the Characters of the Male. 



1 (2). Abdomen straight, abdominal processes small and 



inconspicuous. Eight leg three-segmented, the first 

 segment armed on the inner margin with a hook ; sec- 

 ond and third segments armed at the outer apical angle 

 with a small spine. Process on first segment of left 

 leg but slightly curved. nordenskioldi. 



2 (1). Abdomen flexed to the right; abdominal processes 



large. Eight leg two-segmented. 



3 (4). First segment of right leg with subtriangular toothed 



plate on the inner margin, and a hair at the outer 

 apical angle. First segment of left leg very stout and 

 strongly curved ; second segment unarmed. 



nevadensis. 



