146 NEMESXRIXIDjE. 



the wing some distance before wing-tip. This is no real indi- 

 vidual vein, but is composed of the praefurca, the basal portion of 

 the 3rd vein up to its junction with the 4th, the outer side of the 

 discal cell (upper branch of 4th vein), the continuation of the same 

 branch and, finally, the united ends of the lower branch of the 4th 

 vein and upper branch of 5th vein. The last two sections of 

 this "diagonal" vein (as it is conveniently called) are occasionally 

 joined by a very short veinlet, which may be regarded as the upper 

 prong of the lower branch of the 4th vein. It has no parallel in 

 any other family of Diptera. Additional veinlets occur in some 

 genera and species connected with the 3rd vein, the exact identi- 

 fication of which is perhaps unimportant, especially as no such 

 cases are known amongst Oriental species. In Nemestrina, a non- 

 Oriental genus, but one which may possibly occur in India, the 

 most characteristic venation in the family is reached, presenting a 

 curious, somewhat dragonfly-like network of veins, owing to all 

 the spaces between the 2nd vein and the lower prong of the upper 

 branch of the 4th vein containing a number of transverse veinlets, 

 dividing that part of the wing into a considerable number of small 

 squares. A few similar additional veinlets occur between the 

 lower branch of the 4th vein and the wing-margin. 



Life-ldstory. Larva amphipneustic ; head very small, retractile; 

 twelve body-segments ; posterior spiracles terminal, well separated, 

 placed in a transverse fissure. Of the only species of which the 

 life-history is known, a Ilirmoneura, the larva is parasitic on 

 the early stages of the common Europeau beetle, liliizotrogus 

 solstitiaUs. 



This family is sometimes divided into two subfamilies, (1) the 

 NEMESTRININ^E, with a very long proboscis and short palpi, and 

 (2) the HiRMONEURiNJE, with a very short proboscis, to which 

 character Verrall adds " palpi very long and upturned," but this 

 latter does not hold good. The erection of subfamilies therefore 

 merely on the length of the proboscis does not seem advisable. 

 In any case all the Oriental genera would fall in the Hm- 

 MONEURijO*;. 



Talle of Genera. 



1. Ocelli present 2. 



Ocelli absent (auxiliary vein very short, 



not extending much beyond origin of [p. 154. 



4th vein) ATRIADOPS, Wand., 



2. Palpi moderately long, and with mouth- 



opening always obvious (auxiliary vein [p. 147. 



nearly as Ions 1 as 1st vein) HIRMONEURA, Mg., 



Palpi, proboscis, and mouth-parts wholly 



indistinct 3. 



. Auxiliary vein united to 1st longitudinal fp. 153. 



until beyond middle of wing TRICHOPSIDEA, Westw., 



Auxiliary vein distinctly separate, nearly [p. 155. 



as long as 1st longitudinal CEYLONIA, Licht., 



