388 CHARLES T. BRUES. 



transverse rows besides the four anterior bristles. Proboscis. much 

 shorter than the head ; pal pi bristly. Thorax with one pair of dor- 

 socentral macrochsetse and two marginal scutellar bristles. Wings 

 large, with only a single heavy vein (the third) which is simple at 

 the tip. Costa with fine setae ; reaching to the middle of the wing. 

 Three lighter veins present, the seventh being absent. Legs long 

 and slender, with no longer bristles. 



Female. Eyes reduced in size, no larger than the antennae ; ocelli 

 absent. Thoracic dorsum in one piece, the scutellum being absent; 

 with a single pair of dorsocentral bristles. Wings short, finely hairy 

 and reduced to finger shaped appendages which are no longer than 

 the mesonotum. Dorsal abdominal plates reduced, the rest of the 

 abdomen membranous. At the base is a large trapezoidal plate 

 (second segment), followed by three smaller ones of which the last 

 contains the opening of the gland. Legs stouter than in the male, 

 with no bristles except very delicate spurs on the four posterior tibiae" 



This singular genus is represented by only one species, E. wheeleri 

 Brues, from Texas. It lives in the nest of the blind driver ant, 

 Eciton ccecvm Latr. 



Ecitomyia wheeleri Bines. 

 American Naturalist, May, 1901, p. 347. Figs. 



Male. Length .68 mm. Aiutaeeous, thorax infuscated above. Abdomen 

 piceous on basal three-fourths above, except on the anterior margins of the seg- 

 ments, where it is much paler. Antennae, palpi, face and legs pale testaceous 

 anterior tibise black except at extreme base; hypopygium more or less black, 

 Wings hyaline, veins pale. Costa with very small bristles. The three lighter 

 iliscal veins almost straight. 



Female. Length 1.20 mm. Head and thorax yellowish brown, much darkened 

 above. Abdomen yellowish white, its small dorsal plates darker, the first almost 

 piceous. Legs yellowish. 



ACONTISTOPTKRA Brues. 

 Brues, American Naturalist, xxxvi, 373 (1902). 

 Head very broad, more than one and one half times as wide as 

 thorax, widest at the front angles ; half as long as wide; seen from 

 above regularly arcuate in front, concave behind ; front angles sharp, 

 hind ones broadly rounded. Upper surface of head with a small 

 median pair of macrochaetae, eight marginal ones on lateral and pos- 

 terior edges, one over each eye, a bunch at front angles and a regular 

 series of closely placed ones along the front between the antenna?. 

 Front prolonged over the deep antennal cavity. Thorax small, 



