DESMOMYIA. 107 



Subfamily ARTHROCERATINJE. 



Anteunse obviously elongate, 3rd joint flagelliform, with distinct 

 annulations, arista absent. Front tibiae without apical spurs. 



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

 as follows : — 



First antennal joint as long as 2nd and 3rd 



together ; 4th posterior cell open Desmomyia, Brim. 



Third antennal joint much more than double 



as long as 2nd and 3rd together; 4th pos- [g e "- nov. 



terior cell closed Fararthropkas, 



Genus DESMOMYIA, Brim. 



Desmomyia, Brunetti, Rec. Ind. Mus. vii, p. 462 (1912). 



Genotype, Desmomyia thereviformis, Brim. ; the original species. 



Apparently near, but quite distinct in several characters from 

 Arihroceras* Five posterior cells, 4th without any trace of 

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

 border; remainder of venation in accordance with Williston's 

 figure of the wing of Arihroceras.f Antennae elongate, 1st joint 

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

 3rd 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 in Arihroceras. General appearance of whole insect 

 that of a Thereva, with soft pubescence on thorax and abdomen, 

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

 of Thereva • fore tibia? unarmed, posterior tibiae with two distinct 

 pale spurs each. 



71. Desmomyia thereviformis, Brun. 



Desmomyia thereviformis, Brunetti, Rec. Ind. Mus. vii, p. 462 (1912). 



<$ . 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 stiff black hairs ; eyes bare. Antenna? 

 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 with blunted tip, the style as long as the whole antenna. 

 Thorax 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 ' Xovth-Ainerican Diptera' (3rd ed.). p. 161, fig. 18. 



