AMERICAN DIPTERA. 339 



I'll OKA Latr. 



1804. Latreille, Hist. Nat. des Ins. et Crust., L804, XIV, 394. 



17!»4. Fahricius, En t. Syst. IV. Musca, Tephritis, Bibio. 



1823. Fallen, Phytomyzides, Trineura. 



1804. Meigen, Classif. 1, Trineura. 



1830. Meigen, Syst. Beschr. VI, Phora. 



l.-i.|S. Zetterstedt, Dipt. Scand., Triuntrn. 



1856. Rondani, Prodrotnus, I, 136, l'«lpiini'<ia, Megaselia, Triphllbia. 



1861. Lioy, Atti. Inst. Vend., 1864, Phora, Trisometopia* 



1901. Becker, Mouog. Phoridse, <>. 



GENERIC CHARACTERS. 



Body rather stout, thorax and abdomen stout, well developed. 

 Abdomen with six segments besides a large hypopygium in the 

 male, and a three-jointed exsertable ovipositor, which is never 

 strongly chitinized or horny in the female. Head hemispherical, 

 the front usually broader than long, with four transverse rows of 

 bristles, all of which are reel in ate ; upper three rows each consist- 

 ing of four bristles, lower row with only a single median pair. 

 Eyes widely separated, more or less pubescent ; ocelli present. 

 Cheeks and palpi bristly, the latter often enlarged in the male and 

 less bristly than in the female. Third antennal joint spherical or 

 egg shaped, with dorsal arista. Legs stout, the hind femora usually 

 thickened. Hind tibiae almost always with from one to seven stout 

 macrochjetse on the outer side before the apex, spurs present on the 

 four hind tibiae. Wings large, mediastinal vein distinct, third lon- 

 gitudinal vein forked near the apex, costal vein bristly, posterior 

 wing margin bristly at the root of the wing. 



Table of Species. 



1. Wings with four delicate longitudinal veins 4. 



Wings with only three distinct light veins 2. 



* The species which Lioy chose as type for the genus Trisometopia according to 

 Becker's identification belongs to the present genus in which all the frontal 

 bristles are reclinate. From Lioy's description one would he inclined to place ii 

 elsewhere, but I have placed it here, as the type designated by Lioy belongs to 

 this genus. From the aggregation of types which Lioy indicates for the genus 

 Phora, it is evident that he either had a very confused idea of the characters of 

 the species enumerated or was working with wrongly determined specimens. 

 The first, P. flavicornis Macq., = maculata Meig., is a true Phora: the second, 

 /'. fuliginosa Meig., is a synonym of Gymnophora arcuata Meig., and some of the 

 others belong to other genera. 



TRANS. AM. ENT. SOC. XXIX. OCTOBER. 1903 



