Therevidae. 



153 



yellowish. Occiput yellowish grey with yellow hairs; the occipito- 

 orbital brislles somewhat strong, black, overhanging the eyes; the 

 hairs on the vertex blackish. Antennæ with the first joint thickened, 

 longer than the second and third together; they are brown or blackish, 

 the f!rst joint light brownish pruinose with black and beneath with 

 some yellow hairs. Thorax grey, slightly yellowish, with two more 

 or less distinct, light grey stripes. The disc is very sparingly clothed 

 with erect, black or brownish hairs, and densely clothed with less 

 erect, yellowish hairs. There are four dorsocentral bristles, in single 

 cases I found six. Pleura grey with pale yellowish hairs. Abdomen 

 much as in annulata, the ground colour blackish grey, but silvery 

 pruinose; it is clothed with long, silvery hairs. Venter greyish, spar- 

 ingly clothed with white hairs. Legs with the coxæ and femora grey 

 or blackish grey, the apex of the femora and the tibiæ yellow, the 

 latter narrowly blackish just at the tips; tarsi yellow% blackish brown 

 towards the ends. Coxæ and the anterior femora with somewhat 

 long, white hairs. Wings hyaline, slightly yellowish tinged; veins 



Fig. 47. Wing of T. anilis. 



yellow at the base, brown towards the apex, the diiferent cross-veins 

 slightly blackish seamed; the fourth posterior cell open ; stigma slightly 

 yellowish. Halteres yellowish white, the knob blackish at the base. 



Female. Vertex and frons brownish yellow pruinose with short, 

 black hairs; no frontal cailus; the hairs on the first joint of the 

 antennæ and the occipito-orbital bristles shorter than in the male. 

 Thorax greyish or yellowish brown, sparingly clothed with very short, 

 depressed, yellow, and with some black, erect hairs. Abdomen grey, 

 the three or four last segments yellow at the hind margin; the hind 

 margins whitish or whitish yellow; the first four segments with de- 

 pressed, yellow or pale yellow hairs, the last segments with very short, 

 erect, yellow hairs; on the fourth segment also some erect hairs. 

 Venter grey, sparingly clothed with yellowish hairs which are some- 

 what long at the base. short towards the apex. Legs yellow, coxæ 

 and trochanters grey, tarsi brownish black towards the apex; the hairs 

 on the femora very short. Wings more yellowish than in the male, 



