iqi3.] E. Brunetti : Diptera. 175 



HETERONEURINAE. 



Trigonometopus trilincatus, mihi, sp. no v. 



. (PI. vi, fig. II). 

 Assam, Long. 3-3 ^ mm. 



Head —Fions flattened, horizontal (generic character) ; at its 

 narrowest part, which is opposite the frontal bristles, more than 

 one-third the width of the head, widened rapidly at vertex, 

 brownish yellow. Ocellar triangle well below vertex, small, black. 

 A single pair of frontal bristles just below narrowest part of frons, 

 and removed from eye margins. Two sub-triangular brownish 

 marks on frons placed, so to speak, base to base, but separated 

 from each other, situated midway between the ocellar triangle 

 and the base of the antennae. Two pairs of vertical bristles, the 

 median pair converging, the outer pair, near the corners of the 

 eyes, diverging. Occiput wholly yellow, with a few soft yellow 

 hairs. Face very retreating, with a deep groove each side near 

 the eyes (both generic characters). These grooves and a median 

 stripe are dark brown and very conspicuous, extending from the 

 base of the antennae to nearly behind the eye. and to the mouth 

 opening. Cheeks with a row of about six bristles, placed behind 

 the ends of the facial groove. Proboscis and palpi concealed, 

 brownish yellow the latter moderately long, cylindrical, slender. 

 Antennae brownish yellow ist and 2nd joints with a row of 

 spines at the tip ; 3rd as long as ist and 2nd together, bare, 

 except for miscroscopic pubescence, and with a long black pubes- 

 cent arista inserted on the inner side. A small black spot between 

 the eye margin and the base of the antennae, contiguous to 

 both. 



r/w^M,- Dull brownish yellow, violet-grey-dusted seen from 

 certain directions, .ind with two narrow, well separated median 

 brown stripes from anterior to posterior margin where they 

 nearh^ or quite meet, and are then continued as a single broad 

 stripe to the tip of the concolorous scutellum. Sides of thorax 

 mainly yellowish, but brownish about the shoulders and from 

 there to the wings, the colour probably extending in individuals to 

 a varying extent. Three pairs of dorsocentral br sties, of which 

 the most anterior pair are placed but little in front of the middle 

 of the thorax ; a row of four similar bristles from shoulder to root 

 of wing; two mesopleural, one sternopleural, all three weak. A 

 pair of strong lateral scutellar bristles placed midway between 

 base and tip, and a pair of strong apical ones also. 



Abdomen. — Brownish yellow, blackish at base, and apparently 

 here and there elsewhere : shortly black pubescent ; belly more or 

 less similar. 



Legs. — Pale brownish 3'ellow; fore femora with a number of 

 stiff black hairs below ; posterior femora nearh^ bare, and with a 

 small bristle near tip ; all tibiae with a preapical bristle. Legs 

 generall}' shortly pubescent. 



