AET. 9 TWO-WINGED FLIES OF TEIBE MILTOGEAMMINI ALLEN 33 



which extend in an irreguhir row on parafacials almost to bucca; 

 antennae black, excepting apex of second joint, which is red; in pro- 

 file, buccal width exceeds that of paraiacial and equals one-fourth 

 eye height; head length at vibrissae equals that at base of antennae; 

 palpi yellow, usually with black tips. Thorax with three distinct 

 postsutural dorsocentrals and two sternopleural bristles. Abdomen 

 densely gray pollinose over black, without red spots on the sides, the 

 narrow margins of the segments yellowish brown; with three more 

 or less vague black spots on each of the last three segments; the sec- 

 ond segment bears a strong median marginal pair of bristles, the third 

 and fourth each with marginal rows. Genital segments and forceps 

 subshining black; inner forceps (pi. 2, fig. 7) scarcely twice as long 

 as broad, tapering uniformly to sharp, stout points curved sharply 

 forward at tips, broadly divergent when viewed from behind; outer 

 forceps shorter than inner pair, curved inward to rounded spoon-like 

 tips. Wings without costal spine; with one to two small bristles at 

 base of third vein. 



Female. — Width of front at narrowest 0.24 of head width (measure- 

 ments of five as follows: 0.23, 0.24, 0.24, 0.24, 0.26); vertex, front 

 and face more deeply golden pollinose than in the male; in profile, 

 buccal width equals one-fifth eye height. Thorax and abdomen 

 golden pollinose. Otherwise like tlie male excepting the usual dif- 

 ferences in genitalia and size of pulvUli. 



Length 3.0 to 7.0 mm. 



This species is one of the most common Muscoid flies of North 

 America. Redescribed from a long series of both sexes from all parts 

 of the United States, one male from San Carlos, Costa Rica (Schild 

 and Burgdorf), and one female from Chinandega, Nicaragua (Baker). 

 Townsend's eight specimens from Peru (Euselenomyia pentviensis) , 

 which are before me, differ slightly from the typical North American 

 specimens in having the parafacials more bristly, and the first abdomi- 

 nal segment of the males and some of the females with a pair of 

 distinct median marginal bristles. In much of the western material 

 examined, which includes specimens from Colorado, Idaho, Nevada, 

 New Mexico, Washington, and California, the three black spots on 

 the intermediate segments of the abdomen are sharply defined from 

 the surrounding white ])ollen, and the frontal bristles are noticeably 

 weaker than in tyj^ical eastern specimens. The male genitalia of 

 these Peruvian and western forms are apparently identical with that 

 of the form from the eastern United States, lifter a careful study of 

 available mat(^rial I am inclined to retain all under trUmeata. 



Of four specimens of trilineata determined by me and forwardetl 

 to Major Austen, he finds that one is trilineata by comparison with 

 the type. The others, however, appear to him to represent a dif- 

 ferent species, with which opinion I can not concur. The type of 



54292— 26t -.3 



