SYSTEMATIC ARRANGEMENT OF THE GENERA. 15 



B. Third antennal joint short even in the male, or if somewhat elon- 

 gated, then neither pointed at tip nor with an apical, but, at 

 the utmost, with a subapical arista. 



A. Fourth longitudinal vein simple. 



- 1. Upper side of the thorax convex posteriorly. 



a. Fifth longitudinal vein distinct. 



a. Distance of the posterior transverse vein from the 

 hind margin of the wing equal to its own length 

 or longer. 



Gen. XXIII. Thinophilus. Gen. XXIX. Lyroneurus. 



Gen. XXIV. Peocles. Gen. XXX. Cltrysotus. 



Gen. XXV. Nematoproctus. Gen. XXXI. Teucliopliorus. 



Gen. XXVI. Leiicostola. Gen. XXXII. Synipy on us. 



Gen. XXVII. Futarsus. Gen. XXXIII. Campsicnemus. 



Gen. XXVIII. Diaphorus. Gen. XXXIV. Plagioneurus. 



/?. Distance of the posterior transverse vein from the 



margin of wing shorter than its own length. 



Gen. XXXV. Liancalus. Gen. XXXVII. Hydrophorus. 



Gen. XXXVI. Scellus. 



b. Fifth longitudinal vein altogether wanting. 

 Gen. XXXVIII. Aclialcus. 



2. Upper side of the thorax posteriorly with a flat, somewhat 

 concave, declivity. 



Gen. XXXIX. Me tie terns. Gen. XLI. Xantliocliloms. 



Gen. XL. Chrysotimus. Gen. XLII. Saucropus. 



B. Fourth longitudinal vein forked. 

 Gen. XLIII. Psilopus. 



