1921] NATURAL SCIENCES OF PHILADELPHIA. 69 



Genus ERIOPTERA Mcigcn. 

 1803. Erioptera Meigen, Illiger's Mag., Bd. 2, p. 262. 



Species of the genus Erioptera are relatively abundant in the 

 Amazonian Region. IVIany of these species belong to the subgenus 

 Mesocyphona which reaches its greatest specific development in the 

 Tropics of the New World. A few other forms belong to the typical 

 subgenus Erioptera, although the species of the annulipes group 

 must be considered as being somewhat aberrant. 



Erioptera (Erioptera) micromyia Alexander. Plate IV, fig. 8. 



1920. Erioptera {Erioptera) micromyia Alexander, Journ. N. Y. Ent. Soc, 

 vol. 28, p. 8. 



The type female was from Prata, Brazil, June 30, 1919 (H. S. 

 Parish). A male specimen was taken by Parish at Yurimaguas, 

 Peru, April 17, 1920, and is herewith described as the allotype. 



Allotype. — Male, length about 2.5 mm.; wing 2.5 mm. 



Similar to the type female. Male hypopygium (Plate IV, fig. 8) 

 with the pleurites comparatively large and stout ; two pleural append- 

 ages, the outer one deeply bifid, the outer branch a slender chitinized 

 spine, the inner branch shorter, stout, the apex a little enlarged 

 and covered with minute spinules; inner pleural appendage a flat- 

 tened arm whose apex is obtusely rounded and provided with a 

 few tiny setae. Gonapophyses very large and powerful, about as 

 long as the pleurites themselves, each apophyse appearing as a 

 blackened blade directed caudad, the acute tips curved proximad 

 and subcontiguous with one another at the midline of the body; 

 before the tip on the proximal face, each apophyse is dilated into 

 a thin, flaring blade whose margin is weakly serrate. 



Erioptera (Erioptera) cladophora Alexander. 



1920. Erioptera {Mesocyphona) cladophora Alexander, Can. Ent., vol. 52, 

 p. 142. 



The types are from Manaos, Brazil, October 31 to November 4, 



1919 (H. S. Parish); Itacoatiara, Brazil, October 22, 1919 (H. S. 

 Parish). Additional specimens were taken at Iquitos, Peru, March 

 10 to May 12, 1920 (H. S. Parish); Yurimaguas, Peru, April 17, 



1920 (H. S. Parish). 



Erioptera (Erioptera) annulipes Williston. 



1896. Erioptera annulipes Williston, Trans. Ent. Soc. Lond., 1896, p. 294. 



Igarape Assu, Brazil, January 19, 1912 (H. S. Parish). 



Yurimaguas, Peru, April 7, 1920 (H. S. Parish). 



Amazonian material was sent to Mr. Edwards, of the British 

 Museum, for comparison with Williston's types (females). Mr. 

 Edwards reports the following differences: basal section of Rt 

 shorter than crossvein, less than half as long as R2+3; white pleural 



