DEi=;MOMYlA. 



107 



Subfamily ARTHROCERATIN^E. 



Antennae obviously elongate, 3rcl joint Ha^ellifoi'm, with distiiu-t 

 annulations, arista absent. Front tibite without apical spurs. 



Only two genera occur in India, and they may be distinguished 

 as follo\\s : — 



First autennal joint as long' as 2ud and 3rd 



together ; 4'th posterior cell open Dksmojiyia, Bniu. 



Third antennal joint much more than double 



as long- as 2nd aud 3rd together; 4th pes- [g*^"- ""^'• 



terior cell closed r.vuARTHROPEAS. 



Genus DESMOMYIA, Brun. 



Besmomyia, Brunetti, Piec. Ind. Mus. vii, p. 462 (1912). 



Geivotype, Desmomyia thereviformis, Bi'un. ; the original species. 



Apparently near, but quite distinct in several characters from 

 Arihroceras* Five posterior cells, 4th without any trace oi' 

 contraction towards wing-border; anal cell closed just before wing- 

 border ; remainder of venation in accordance with Williston's 

 hgnre of the wing of Arthroceras.f Antennae elongate, 1st joint 

 as long as 2nd and 3rd together, cylindrical, 2nd broadly annular, 

 ;5rd elongate with an apical style-like prolongation. Eyes con- 

 tiguous for a considerable distance, bare ; three ocelli. Proboscis 

 rather short, stout, cylindrical; palpi elongate, narrow. Face 

 with two dividing furrows below antennae and rather bulbous 

 cheeks, as iti Arthroceras. (general appearance of whole insect 

 that of a Thereva, with soft |)nbescence on thorax and abdomen, 

 the latter with seven distinct segments. Legs slender, like those 

 of Thereva ; fore tibiae unarmed, posterior tibiae with two distinct 

 pale spurs each. 



71. Desmomyia thereviformis, Bmn. 



Desmomyia thprevifonnis, Brunetti, Eec. lud. Mus. vii, p. 462 (1912). 



S . Head with vertex small, dark ; occiput of a lighter grey 

 than the dark blackish-grey face ; proboscis and palpi blackish 

 grey ; the whole head with stiiF black hairs ; eyes bare. Antennae 

 dark grey; 1st joint elongate, cylindrical; 2nd broadly annular, 

 half the length of the 1st; the 3rd joint is best described as 

 diamond-shaped, with rounded angles, the greatest breadth being 

 beyond the middle ; the tip produced into an elongate narrow 

 style \\ith blunted tip, the style as long as the whole antenna. 

 Thora.i- dark grey above, with three separated, moderately broad, 

 blackish stripes, the outer ones with a tendency to an interruption 

 in front of the middle; sides and scutellum moderately dark grey, 



* The description of this genus is not accessible in India. 

 t 'North-American Diptera' (3rd fid.), p. 161, fig. 18. 



