AMERICAN DIPTEKA. 381 



as in G. atra, and the third antennal joint of the male falls short of 

 reaching the vertex. The chsetotaxy and other characters do not 

 differ, however. 



GYMNOPHORA. 

 Macquart, Histoire Naturelle des Dipteres. ii, 631. PI. xxiv, fig. 5 (1835). 

 Scliiner, Fauna Austriaca, Diptera, ii, 346 (1864). 

 Lioy, Atti. Soc. Veneti., 79 (1864). 



Osten Sacken, Catalogue North American Dipt., 2nd Edit., 212 (1878). 

 (Refers to its occurrence in North America.) 



"Palpi little protruding, with short hairs, front hare, very wide, 

 last joint of antennae globular. Feet bare; posterior femor not 

 thickened. Wings not ciliated ; marginal nervure bifurcated at its 

 extremity ; submarginal arcuated, not attaining the apex of the 

 wing; median nervures sinuous (PI. 24, fig. 5). 



" Phora arcuata Meig. differs so much from the others in most of 

 its characters that I have determined to separate it. The name I 

 give to this genus makes allusion to the nudity of the principal 

 organs." — Macquart, /. c, translated. 



This easily recognized genus, of which only one species is known, 

 is distinguished, as above indicated, by the absence of setae on the 

 front, thorax, wings and legs, in fact by almost absolute nudity. In 

 front of the wing are two or three fine hairs, and the vertical bris- 

 tles of the head are also represented by four weak and short bristles 

 on the vertex, but the apical spines of the tibiae are absent. Scarcely 

 less characteristic is the course of the fourth longitudinal vein, 

 which curves forward and ends far before the tip of the wing. The 

 third vein reaches considerably past the middle of the wing, and the 

 first ends only a little before the second. The scutellum has only 

 two small bristles, the dorsum of the thorax being bare otherwise. 

 The pulvilli and empodia are present. 



Gyuinypliora arcuata Meig. (Plate ix, fig. 57.) 



1830. Phora arcuata. Meigen, Syst. Beschr, vi, 222. PI. Ixiii, fig. 9. 



1835. Gymnophora arcuata, Macquart, Hist. nat. d. Dipt. ii. PI. xxiv, fig. 5. 



1864. Gymnophora arcuata, Schiner, Fauna Austriaca, ii, 346. 



1864. Lioy, Atti. Soc. Veneti., p. 79. 



1864. Phora debilis, Haliday Entom. Mo. Mag., i, 179. 



1878. Gymnophora arcuata, Osten Sacken, Cat. N. Am. Dip., 2d ed.. 212. 



Head and antennae black, thorax, including pleurae the same, abdomen more 



variable, the middle of the upper surface usually yellowish, venter yellow. Coxae 



and feet yellow, posterior femora sometimes a little infuscated. Halteres clear 



yellow. Wings infuscated along the veins, which are blackish. Hypopygium of 



TRANS. AM. ENT. SOC. XXIX. DECEMBER, 1903 



