58 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 52. 



and enlarged at the distal end. This enlargement resembles some- 

 what a truncate spoon, the concave surface being faced inward to- 

 ward the midline. 



Front wing. — The pterostigma is vestigial. The apical end of the 

 radial cell is rounded off and lies on the costal border. Of the three 

 cubital cells the first is about as long as the second and third combined. 

 The first cubital cross vein is almost straight; the second is almost 

 sigmoid in shape; and is far from parallel with the first so that the 

 second cubital cell is much narrower on the radial vein than on the 

 cubital, on which it receives both discoidal cross veins. The third 

 cubital cross vein is quite strongly directed outward and roundly 

 curved at its posterior end so that the rounded apical end of the third 

 cubital cell frequently extends beyond the end of the radial cell. The 

 angle formed by the radial and third cubital cross veins and opening 

 outwardly is acute. The second discoidal cross vein posterior to its 

 junction with the cubital is angularly bent outward and subtends 

 at the angle a short longitudinal vein. The first submedian cell is 

 as long or longer than the second, which gradually increases in width 

 toward its apical end. The basal vein arises proximal to the termi- 

 nus of the first submedian cell. 



Hind wing. — The retinaculum, consisting of an unbroken row of 

 small hooklets, begins near the origin of the radial vein, which extends 

 distally almost to the apical border of the wing. The median cell is 

 extremely long. The cubital vein arises distal to the terminus of 

 the submedian cell. The posterior angle of the submedian cell, 

 formed by the submedial and submedial cross veins, is, like that of 

 Steniolia, obtuse. The submedial vein terminates in the anul sinus. 

 The wings, particularly the anterior pair, in both sexes of many 

 species are more or less infumated, the infumation being more evi- 

 dent in the female than in the male of the same species. The char- 

 acter and the degree of infumation is of value in the separation of 

 species. 



The legs are relatively long and slender. The middle coxae are 

 not contiguous, and on the inner distal margin of the hind pair of 

 some species there is a distinct tooth. The middle femora of the 

 males of some species are compressed below to a sharp edge and in 

 others there is present basally below a prominent, flattened tooth. 

 The middle tibia at the distal end is provided with a single spur. 

 The anterior tarsus of the female is flattened and provided with a 

 strong tarsal comb; in the case of the male, with the exception of a 

 few species, the anterior tarsus is not flattened and the tarsal comb 

 is but weakly developed. The pulvilli are well developed and the 

 claws simple. 



The pubesence is short and sparse, not at all prominent except 

 on the vertex. The punctations are evident, fine, and usually uni- 



