TABLE FOR THE DETERMINATION OP THE GENERA. 11 



TABLE FOR THE DETERMINATION OF THE GENERA. 



, ( First autennal joint hairy above. 2 



( First antennal joint glabrous above. 16 



o ( Hypopygium disengaged. 



( Hypopygium more qr less imbedded. 14 



r> f First joint of the hind tarsi bristly. 4 



I First joint of the hind tarsi not bristly. 5 



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

 4 J Gen. I. HYGROCELEUTHUS. 



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



Gen. II. DOLICHOPUS. 



, ( Palpi of the male unusually large. Gen. XII. DIOSTBACUS. 



( Palpi of the male small 6 



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

 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 



The end of the fourth longitudinal vein is only gradually deflected 

 anteriorly. 9 



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

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



Gen. IV. PABACLIUS. 



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

 the rounded flexure, runs in a straight line. 



Gen. V. PELASTONEUEUS. 

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

 9 < Gen. VI. TACHYTBECHUS. 



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

 , f Proboscis and palpi very much prolonged. Gen. VII. OBTHOCHILE. 

 \ Proboscis and palpi not prolonged. 11 



, , ( Scutellum hairy. Gen. VIII. SYBISTBOMA. 



\ Scutellum not hairy 12 



1 9 ( Hypopygium sessile. Gen. IX. HERCOSTOMUS. 



( Hypopygium pedunculated. 13 



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



( Second antennal joint rudimentary. Gen. XI. HALTEBICEBUS. 



