ART. 1 NEW DIPTERA FROM SOUTH AMERICA ALDRICH 15 



below has mostly black hairs, the white ruff being small. Proboscis 

 and palpi of ordinary form, the latter black or very dark reddish; 

 vibrissae almost at edge of mouth, facial ridges with strong bristles 

 almost meeting the frontals, which descend nearly or quite to the 

 arista. Second antennal joint more than half the third, arista with 

 basal joints short. Female with three pairs of orbital bristles, the 

 anterior proclinate, the other two turned more outwardly ; ocellars 

 present and proclinate. Thorax with three posterior dorsocentrals, 

 acrostichals 3,3, sternopleurals 2,1, inner presutural present. Scu- 

 tellum with a median discal pair of upright slender bristles close 

 together, and another pair nearer the tip and farther apart, the 

 space between the discals and the tip bare; three lateral pairs of 

 scutellar bristles, the last long and divergent, no apicals between 

 them. Intermediate abdominal segments with each a single pair of 

 discals. Middle tibia with three or four bristles on outer front side ; 

 hind tibia not ciliate, males with front pulvilli and claws moderately 

 elongated. Fourth vein ending far before the tip of wing, third 

 with only a few hairs at base, first bare. Costa with distinct spine. 



KBX TO SPECIES OF INCAMTIA 



1. First posterior cell petiolate; second to fourth abdominal segments with 



sharply defined pollinose pale band covering basal third, remainder of these 



segments shining black striata, new species. 



First posterior cell open or barely closed in margin 2 



2. Infrasquamal hairs absent ; basal pollinose abdominal bands as in preceding, 



but still narrower and more or less interrupted in the middle; scutellum 



pollinose only at tip spinicosta, new species. 



Infraquamal hairs present; pollen on abdomen not confined to distinct 



basal bands ; scutellum pollinose from base to tip 3 



8. Abdomen mostly gray pollinose, hardly at all tessellated, the pollen in the 



male extending upon the venter cuzcensis Townsend. 



Abdomen mostly dark, the pollen tessellated, in the male not extending upon 



the venter chilensis, new species. 



INCAMYIA SPINICOSTA, new species 



Male. — Front one-fourth the headwidth at narrowest part (by 

 micrometer .24, .26 and .26, in three specimens) ; parafrontal and 

 parafacial silvery, uniform in color, the parafacial a little narrower 

 than width of third antennal joint; cheek one-third the eye height, 

 its anterior part with a few bristles below the transverse impression. 



Abdomen shining black, with silvery basal band on segments 

 2-4; first segment with a large pair of median marginals; second 

 segment with large discal and marginal pairs; third with discal 

 pair and marginal row of 12; fourth with numerous erect discals 

 irregularly arranged. Genitalia small, black. Posterior forceps 

 minute, separate, almost straight; anterior forceps (outer) red at 

 base, flat and blade-like. 



