204 Annals of the Carnegie Museum. 



9, while on 10 it, with its ascending branches, encloses a round, blue 

 spot on each side of the dorsum, or the two spots are confluent. 3-6 

 have a narrow transverse basal yellow ring and the sides inferiorly of 

 most of the abdominal segments are yellow, more obscure nearer the 

 hind end of the abdomen. 



Hind margin of 10 with a small mid-dorsal excision, not elevated. 

 Superior appendages subequal in length to 10, reddish, hairy, in dorsal 

 view conical, apex subacute, and, owing to the hairs, having the appear- 

 ance of being slightly incurved ; in profile view each is somewhat 

 mitten-shaped, the " thumb " being represented by an inferior process, 

 directed caudad, at about three-fifths of the length. 



Inferior appendages in profile view conical, directed somewhat 

 upward as well as caudad, not quite reaching to the level of the tips of 

 the superiors, yellow ; in ventral view the outer side is prolonged to 

 form the chief part of each appendage, and is curved slightly toward 

 its fellow of the opposite side, with a small blackish hook on the mesial 

 side at apex. 



Legs brownish yellow, 7 spines in the anterior row of the third tibia, 

 tooth of the tarsal nails very small. 



Wings clear, veins brownish-yellow, stigma yellow, moderately 

 oblique, surmounting one cell or less, rather distant proportionally (2 

 mm.) from the wing-tip, costal edge longer than the proximal or 

 distal edge on the hind wing and often also on the front wing. Anal 

 vein separating from the hind margin of both front and hind wings at 

 least as far proximal to the cubito-anal cross-vein as the latter is long ; 

 8-10 (10 most frequent) postnodals on the front wings, 6—8 (8 most 

 frequent) on the hind. M 2 on the hind wings arising nearest the 

 fourth or third postnodal. 



9. Differs from the description of the male as follows: Hind 

 margin of prothorax trilobed, median lobe not as prominent as the 

 corresponding part of the male; dorsum of abdominal segment 10 

 elevated into a median ridge ; appendages reddish or yellowish, as 

 long as 10 ; vulvar spine present, genital valves pale, reaching caudad 

 not beyond the level of the hind end of 10; 7-10 postnodals on the 

 front wings, 9 most frequent ; 6-8 on the hind wing, 8 most frequent. 



The differences in color between the two sexes are confined to the 

 abdomen, but the females show differences among themselves by 

 which, as in other genera, they may be grouped as similar to, or 

 markedly different from, the males in abdominal markings. 



