Dec, i9i9-] Bequaert: New Nemestrinid Fly. 305 



sity, Museum of Comparative Zoology at Cambridge, Museum of the 

 Brooklyn Institute of Arts and Sciences, private collection of Prof. 

 Jas. S. Hine, Mr. C. W. Johnson and of the author. 



Paratypes (2 J) from Helotes, Bexar Co., Texas, July 1, 1917 (J. 

 Bequaert Coll.), in the author's collection. 



The North American Nemestrinidas usually placed in Hirmoneura 

 belong to three very distinct groups, which must, I believe, be treated 

 as genera. H. clausa Osten-Sacken is the type of Parasymmictus 

 Bigot, 2 which should be considered a valid genus, not merely on 

 account of its eyes (bare, dichoptic in the male) and the peculiarities 

 of the venation (three submarginal cells, the third of which is closed; 

 second posterior cell closed), but more so because the proboscis is 

 aborted, hardly visible, without fleshy labella ; furthermore, the palpi 

 are minute and the base of the wing has no alula. H. tcxana Cock- 

 erell and H. brevirostris Macquart belong in Hyrmophlxrba Rondani 3 

 (type: H. brevirostris): there are three submarginal cells and the 

 eyes- are in both sexes holoptic and densely pilose. H. flavipcs Wil- 

 liston, H. psilotes Osten-Sacken and H. bradleyi agree with the type 

 of Hirmoneura Meigen, 4 H. obscura Meigen, in having only two sub- 

 marginal cells in the wings and dichoptic eyes in both male and 

 female. In H. obscura, however, the eyes are distinctly though 

 shortly pilose, 5 whereas they are completely bare in the three Ameri- 

 can species just mentioned. This difference is in my opinion of suffi- 

 cient importance to warrant the making of a new subgenus for these 

 North and Central American forms; moreover, further comparative 

 study may bring to light additional distinguishing characters between 

 these and the typical Hirmoneura, which are thus far unknown in 

 North America. 



The North and Central American so-called " Hirmoneura " may 

 then be separated as follows : 



1. Proboscis very small, aborted, hardly visible, without fleshy labella ; palpi 

 minute ; wings with three submarginal cells, without alula ; eyes bare, 

 dichoptic in the male (? unknown) Parasymmictus Bigot. 



2 Ann. Soc. Ent. France (5), IX, 1879, Bull., p. lxvii. 



3 Archivio per la Zoologia, Modena, III, pt. 1, 1863, p. 51. 



4 Syst. Beschreib. Europ. Zweifl. Ins., II, 1820, p. 132. 



5 Lichtwardt, Deutsch. Ent. Zeitschr., 1909, p. 514. 



