North American < 'entrap a g idee. 257 



men is asymmetrical, flexed to the right, and consists of six 

 segments (furca included). The segments vary but little 

 in length, the furca being, however, the shortest, the fifth, 

 second, and first increasing in length in the order of their 

 mention, the third and fourth subequal, each slightly longer 

 than the first. Seen from above, the first segment is pro- 

 duced slightly to the left at its posterior margin. Second, 

 third, and fifth segments armed with processes on the right 

 side. The process on the second segment is a broad thin 

 lamina about as long as the segment is broad, smooth on the 

 convex anterior margin and for about the distal fourth of its 

 posterior margin (which is almost straight), but for the re- 

 maining three fourths of this margin provided with minute 

 irregular teeth having a tendency to point toward the abdo- 

 men ; apex acute and slightly recurved. The process on the 

 third segment springs from the posterior part as a broadly 

 rounded smooth hyaline lamina slightly longer than broad. 

 Fourth segment unarmed. Fifth segment provided with two 

 processes, the anterior one (pointing forward and upward) 

 consisting of a narrow irregularly triangular plate with an 

 acute apex and smooth margins, the posterior one having the 

 form of a truncated triangle, armed at the apical margin with 

 three or four large equal teeth and one or two much smaller 

 ones. Posterior to this process the right margin of the seg- 

 ment is armed with a row of bead-like tubercles which, near 

 the suture between the furca and this segment, lengthen to 

 form two or three blunt spines. Furcal rami slightly longer 

 proportionally than in the female, but similar in other respects. 



Antenna; 25 - segmented, long and slender, extending 

 slightly beyond the posterior end of the third abdominal seg- 

 ment in the female and beyond the fourth segment in the 

 male. Right male antenna geniculate between the 18th and 

 19th segments; segments 19, 20 and 21, and 22 and 23 

 ankylosed ; antepenultimate article unarmed. 



Right fifth leg of male two-segmented. First segment 

 irregularly pentagonal, the longest base forming the outer 

 margin, which is armed near the distal angle with a delicate 

 seta; basal half of inner margin armed with a broad irregu- 



