Ko. 1935. MUSCOID FLIES FROM SOUTH AMERICA— TOWNSEND. 307 



often more or less yellowish on margins. One female shows practi- 

 cally no brassy tinge to pollen either on head, thorax, or abdonien. 



Type.—Csit. No. 15145, U.S.N.M. Female, February 11, 1910; 

 TD 3936, e. 



Subfamily PSBTJIDOIDEXIIT^^E;. 

 Genus OPHIRODEXIA Townsend. 

 Ophirodexm Townsend, Ann. Ent. Soc. Amer., vol. 4, 1911, pp. 134, 147. 



Belongs in Pseudodexiinas, and rims to Doleschalla, Graphia, and 

 Pachygraphia in Braiier and Bergenstramm's tables, but differs mark- 

 edly from these forms. Front about twice length of face, the antennae 

 inserted far below middle of eyes. Eyes bare, extending lower in male 

 than in female. Front of female fully width of one eye, that of male 

 hardly two-thirds eye-width. Female with two proclinate orbital 

 bristles, none in male. Parafacials and cheeks of female wide, former 

 about one- third and latter about one-half eye-height; those of male 

 narrower, former being less than one-fourth and latter hardly one- 

 third eye-height. Facialia bare save several bristles next vibrissae. 

 Frontal bristles stopping at base of antennae. Facial plate small, cut 

 off below, oral margin not prominent, vibrissae on oral margin. 

 Antennae reaching nearly to vibrissae, second joint short. Arista 

 short, densely plumose on both sides in female, less plumose on under- 

 side in male. Proboscis very short and fleshy, palpi slender. Ocellar 

 bristles weak, distinct in female but reduced to a pair of delicate hairs 

 in male. Occiput bulged below, especially noticeable in its invasion 

 of cheek-area, sunken above leaving an excavated area between eyes 

 especially noticeable in male. 



Two sternopleural and three postsutural bristles. Scutellum with 

 one strong basal lateral bristle, and an apical pair of same strength 

 barely decussate at ends; discal pair hairlike, also a hairlike mar- 

 ginal bristle between the lateral and apical. Abdomen moderately 

 elongated, subcorneal in male, first segment widest, tapering evenly 

 to apex of anal segment, second and third segments equal in length 

 and longer than others. Abdomen of female a little broadened in 

 middle. First segment with a median marginal pair of very weak 

 macrochaetae, hardly stronger in male than the bristly hairs of abdo- 

 men; second segment with a median marginal pair of stronger ones; 

 third and fourth segments with a marginal row of eight or ten bristles, 

 the upper ones strongest and those of third segment longest. Weak 

 marginal bristles on sides of first two segments. Legs not elongate, 

 without strong bristles, tarsi normal, claws and pulvilli moderately 

 short in both sexes. Wings rather narrow; apical cell narrowly open 

 to almost closed, terminating just before extreme mng-apex; apical 

 crossvein lightly bowed in, parallel with the subsinuate hind cross- 



