ART 18 DIPTERA OR TWO-WINGER FLIES ALDRICH 29 



a row of five orbitals, the uppermost of which is reclinate. In both 

 sexes the ocellars are present, the frontals diverge below in a broad 

 curve almost to the eye margin at the level of the middle of the 

 second antennal joint; the antennae are slender and small, the sec- 

 ond joint equal to the third ; the face is very flat, the parafacials bare 

 and wide, the facial ridges bare, the vibrissae distinctly above the 

 edge of the mouth. Bucca in profile about one-fourth the eye height. 

 Palpi and proboscis ordinary. The thoracic chaetotaxy is the same 

 as in Belvosia unifasciata Robineau-Desvoidy {Triachora of Town- 

 send) and in thorax, abdomen, legs and wings there are no generic 

 characters unlike the latter. 



Brauer and Bergenstamm include Brachycoma nigriceps Van der 

 Wulp in Atacta from a specimen * ; but as the third antennal joint 

 is twice the second I doubt if they understood the genus as herein 

 restricted. 



The species crescentis Townsend seems clearly congeneric from the 

 male in the National Museum ; the characters given by Townsend for 

 the genus Atactovmna are all specific in my opinion. 



TABLE OF SPECIES 



1. Fourth abdominal segment covered with dense golden pollen ; hair of me- 



dian portion of second and third abdominal segments recumbent ; second 

 abdominal segment almost always destitute of median marginals; male 



with silvery parafrontals brasiliensis Schiner. 



Fourth abdominal segment with gray pollen ; hairs of median region of 

 second and third abdominal segments erect ; second abdominal segment 

 with a pair of median marginal bristles 2 



2. Antennae and palpi black, tip of latter yellow crassiceps, new species. 



Antennae with second joint yellow, palpi yellow 3 



3. Male with bright silvery pollen on parafrontals, strongly contrasting with 



the white or yellowish parafacials argentifrens, new species. 



Male with the strongly widened parafrontals more chalky white, almost 

 concolorous with parafacials crescentis Townsend. 



ATACTA BRASILIENSIS Schiner 



Atacta 'brasiliensis Schiner, Novara Reise, 1S6S, p. 328. — Brauer and 

 Bergenstamm, Zweifl. Kais. Mus., pt. 4, 18S9, p. 96, fig. 57 ; pt. 5, 1891, 

 pp. 340, 365; pt. 6, 1893.— Townsend, Journ. N. Y. Ent. Soc, vol. 23, 

 1915, p. 64.— C. S. Brimley, Ent. News, vol. 33, 1922, p. 21. 



Brachycoma laticeps Van deb Wulp, Biologia Cent.-Amer., Dipt., vol. 2. 

 1890, p. 92. 



Atacta apicalis Coquillett, Revis. Tachin., 1897, p. 83. 



Originally described from a female taken in Brazil, and afterward 

 collected by Townsend in Peru, the species ranges northward to the 

 vicinity of Washington. Specimens from North America in the 

 United States National Museum are as follows: One male, Chiriqui 

 Province, Canal Zone, reared from Remigia repanda Fabricius by 



* Zweifl. Kais. Mus., pt. 5, 1891, p. 365. 



