ART 18 DIPTEKA OR TWO- WINGED FLIES ALDRICH 23 



and close together reaching down to middle of second antenna! 

 joint, and only moderately diverging. Back of head with all black 

 hairs. Head otherwise as in comata. 



Thorax black, striped as in comata, but the pollinose parts are 

 more yellowish, the scutellum is wholly bordered (seen from be- 

 hind) with this color, and it extends across the prescutellar region 

 except a brown space at middle. No prescutellar or other acros- 

 tichals; the dorsocentral usually occurring behind the suture is 

 missing, leaving only two posterior. Sternopleurals 3. Calypters 

 white, bare. 



Abdomen decidedly bluish in ground color, bases of the segments 

 thinly white pollinose, the pollen denser at the sides and below and 

 diminishes gradually behind, leaving only the apical third and 

 a median stripe on segments 2 to 4 entirely shining. No median 

 marginals on segments 1 and 2, a strong erect row on 3 and 4. 

 Genital segments rather large, black, with erect hair, which becomes 

 almost bristlelike on the apex of the first. The thick broad penis is 

 the most characteristic part. Fifth sternite with simple diverging 

 sides, inconspicuous. Wings as in comata. Legs as in comata, but 

 no suberect or villous hairs on the middle tibiae. 



Length, 7.5 and 8.5 mm. 



Described from two males collected by C. H. T, Townsend on 

 Huascaray Ridge, Jaen Province, Peru, on September 21. 



Type.—M2lQ, Cat. No. 26843, U.S.N.M. 



XOTOCHAETA ANGUSTA, new species 



Male. — Blackish, the pollinose markings distinctly golden in color 

 except on the lovrer part of the pleurae and legs. Head some- 

 what narrower in general outline than in comata, but the front at 

 narrowest slightly wider; parafacials a little wider than the narrow 

 third joint. Thorax with four golden pollinose stripes, the inner 

 ones nearly contiguous in front; the median brownish-black stripe 

 reaches beyond the middle of the scutellum, the two pollinose 

 stripes on each side coalesce just in front of the scutellum; one pair 

 of small, but distinct prescutellars ; sternopleurals 2. Abdomen 

 with a median shining blackish stripe which expands on the hind 

 margins of the second and third segments, extending around to the 

 A'enter and more or less forward on the lat'?!!il dorsal portion. No 

 median marginals on the second segment, tlie tiiird with three pairs. 

 Oenital segments black, yellow pollinose, the genitalia small, black- 

 ish. Legs black, middle tibia with one bristle on outer front side. 

 Wings subhyaline: third vein with about six hairs at base. 



Length, 7.2 mm. 



One male. Corazal. Canal Zone, Panama, June, 1911 (Busck). 



Type.—M?L\e, Cat. No. 26844, U.S.N.M. 



