TABLE FOR THE DETERMINATION OF THE GENERA. 11 



TABLE FOR THE DETERMINATION OP THE GENERA. 



-■ ( First antenna! joint hairy above. 2 



( First antennal joint glabrous above. 16 



o ( Hypopygium disengaged. 3 



( Hypopygium more or less imbedded. 14 



f First joint of the bind tarsi bristly. 4 



(. First joint of the hind tarsi not bristly. 5 



f Face descending as far as the inferior angle of the eye. 



. Gen. I. Hygroceleuthus. 



4 \ 



I Face not descending as far as the inferior angle of the eye. 



Gen. II. Dolichopus. 



r ( Palpi of the male unusually large. Gen. XII. Diostkacus. 



I Palpi of the male small 6 



i The last portion of the fourth longitudinal vein is parallel, or almost 



n i so, to the third longitudinal vein. Gen. III. Gymnopternus. 



The last portion of the fourth longitudinal vein is distinctly convergent 



towards the third longitudinal vein. 7 



" The end of the fourth longitudinal vein is abruptly, or at least steeply 



deflected anteriorly. 8 



j The end of the fourth longitudinal vein is only gradually deflected 



t anteriorly. 9 



' Arista with the usual pubescence ; the end of the fourth longitudinal 



vein, beyond the angular flexure, runs in a curve. 



Gen. IV. Paraclius. 



Arista short-plumose ; the end of the fourth longitudinal vein, beyond 



the rounded flexure, runs in a straight line. 



I Gen. V. Pelastoneurus. 



The face reaches down to the inferior corner of the eye. 



Gen. VI. Tachytrechus. 



The face does not reach down to the inferior corner of the eye. 10 



} Proboscis and palpi very much prolonged. Gen. VII. Orthochile. 



1\ 



8 



i 



Proboscis and palpi not prolonged. 11 



,, ( Scutellum hairy. Gen. VIII. Sybistroma. 



( Scutellum not hairy 12 



19 ( Hypopygium sessile. Gen. IX. Hercostomus. 



1 Hypopygium pedunculated. 13 



, ( Second antennal joint of usual shape. Gen. X. Hypophyllus. 



1 Second antennal joint rudimentary. Gen. XL Haltericerus. 



