56 PROCEEDINGS OF THE ACADEMY OF [Part I 



notum dark brown. Pleura pale testaceous yellow, the dorsal 

 pleurites with a brown longitudinal stripe, extended caudad to the 

 postnotal region. Halteres light yellow. Legs with the coxae and 

 trochanters pale yellow, the margins of the latter narrowly dark 

 brown ; femora yellow, the tips narrowly but distinctly dark brown ; 

 tibiae and tarsi pale yellow. Wings with a pale yellowish tinge; 

 stigma oval, dark brown, conspicuous; much paler brown crossbands 

 arranged as follows: Just beyond the base of the wing, beginning 

 in cell M, continued to the anal margin at the end of vein 2nd A; 

 an ill-defined band along the cord; outer end of cell ^.s^ Mo seamed 

 with darker; wing-apex in cells Rs, Ri and 3nd Mi indistinctly dark- 

 ened; veins yellow, more brownish in the infuscated areas. Vena- 

 tion: Sci ending at about opposite four-fifths Rs, Sci a short distance 

 from its tip; i^s short, gently sinuous to almost straight; /?2 + 3 rela- 

 tively short, about equal to or approximately a fifth longer than 

 Rs, gently bisinuous; r-m a little longer than the deflection of Ri + i', 

 cell 1st M? large, the proximal margin arcuated, oblique; basal 

 section of ilf 1 + . longer than the second section, r-m being near mid- 

 length of the cell 1st M2; m a httle shorter than the outer deflection 

 of M,; basal deflection of Cui at or close to the fork of M. Basal 

 abdominal tergites annulated dark brown and obscure brownish 

 yellow, the basal two-fifths of each segment being dark brown, 

 the apical three-fifths brownish yellow; sternites yellow. 



Habitat. — Peru. 



Holotype, cf , Iquitos, March 2, 1920 (H. S. Parish). 



Allotopotype, 9 , March 5, 1920. 



Paratopotypes, 2 cf' s, March 4, 1920. 



Rhamphidia uniformis Alexander. 



1914. Rhamphidia uniformis Alexander, Trans. Am. Ent. Hoc, vol. 40, 

 p. 230. 



Prata, Brazil, June 30, 1919 (H. S. Parish). 

 Teffe, Brazil, January 28, 1920 (H. S. Parish). 

 Napo River, Peru, June 4-15, 1920 (H. S. Parish). 



Rhamphidia albitarsis Osten Sacken. 



1887. Rhamphidia albitarsis Osten Sacken, Berl. Ent. Zeitsch., vol. 31, 

 p. 184. 



Yurimaguas, Peru, March 31-April 22, 1920 (H. S. Parish). 



A variety of R. albitarsis with the white of the fore and middle 

 tarsi very narrowly restricted was taken at Iquitos, Peru, May 6, 

 1920 (H. S. Parish). 



Genus ORIMARGA Osten Sacken. 

 1S59. Orimarga Osten Sacken, Mon. Dipt. N. Amer., part 4, p. 120. 



Orimarga pallidibasis sp. n. 



General coloration brown, grayish pruinose; pleura with a dark 

 brown longitudinal stripe; legs with the tibiae and tarsi white, the 



