TABLE FOR DETERMINING THE GENERA. 45 



/• Antennae 14- (sometimes apparently 15-) jointed (Section I. Limno- 



4] bina). fo,S"| v 9 



(Antennae 16-jointed. 1 5 



'The first longitudinal vein ends in the costa ; tibiae without spurs at 

 the tip (Section II. Limnobina anomala). 13 



<j The first longitudinal vein is usually incurved towards the second 

 and ends in it ; tibiae always with spurs at the tip (Section VII. 

 Cylindrotomina). 43 



6 ( Tibiae without spurs at the tip (Section III. Eriopterina). 22 



I Tibiae with spurs at the tip. 2 7 



f Subcostal cross-vein posterior to the origin of the second longitudinal 



,_ ! vein. 8 



I Subcostal cross-vein anterior to the origin of the second longitudinal 

 L vein ; Tab. II, fig. 14-18 (Section VI. Amalopina). 38 



r, ( Antennae 16-jointed (Section IV. Limnophilina). 32 



I Antennae from 6- to 10-jointed (Section V. Anisomerina). 35 



Section I. Limnobina. 



/■ Proboscis longer than the head and thorax taken together. 



9 < Gen. II. Geranomyia. 



(. Proboscis not longer than the head. 10 



, ft ( Antennae pectinate or subpectinate. Gen. III. Rhipidia. 



( Antennae of the ordinary structure. 11 



A cross-vein unites the sixth and the seventh longitudinal veins. 



Gen. V. Trochobola. 

 No cross-vein between the sixth and the seventh longitudinal veins. 12 

 r The forceps of the male consists of two movable fleshy lobes ; tip of 

 the auxiliary vein usually opposite, or anterior, or only a short 

 distance posterior to the origin of the second vein ; marginal 

 cross-vein always at the tip of the first longitudinal vein ; feet 

 slender. Gen. I. Dicranomyia. 



The forceps of the male consists of two horny hooks ; tip of the aux- 

 iliary vein usually far beyond the origin of the second vein ; 

 marginal cross-vein sometimes at the tip, but often some distance 

 before the tip of the first longitudinal vein ; feet comparatively 

 stout. Gen. IV. Limnobia. 



1 In Elephantomyia the antennae are 15-, in Toxorrhina 12-jointed; in 

 both cases through the evident coalescence of several joints at the basis 

 of the flagellum ; but as both genera have a rostrum which is nearly as 

 long as the body, they will not easily be mistaken. 



2 The spurs being sometimes very small, the tibiae have to be very 

 closely examined. 



"I 



12 



