FAMILIES XYLOPHAGIDiE AND SYRPHID^E. 183 



TABANrs . 



Sooty black. In some lights, the abdomen above is ghiucous ; beneath, it has a shade of 

 greenish blue : eyes faintly bronzed. Face obsolete, in consequence of the great ex- 

 tension of the eyes, which meet on tlie top, divaricating only just above the base of 

 the antennae, leaving a small triangular area through which the median line passes, 

 and which is also traversed transversely by two grooves : this area is occupied by six 

 or eight little glossy eminences. Legs and breast covered with a jet black jiubescence. 

 The form of the eye is remarkable ; the top of the head being cajiped, as it were, with 

 the organ, wliich projects directly in front. Tlie insect differs entirely from tlie two pre- 

 ceding species, ami has not probably received a specific name. 



Xylophagidae. 



MiD.\s FiLATis. (Plate xxviii, fig. 11.) 



MnscA cLAVATUs ( Dfurj). 



Black : second alidominal segment yellow upon the superior parts ; wings copper-brown 

 and submetallic, scarcely transparent. Length 1 J inch ; expansion of wings, 21. 

 This species, so far as my observations extend, is a rare insect in New-York. It is easily 

 distinguished by the yellow segment of the abdomen referred to, which extends only to 

 the sides, the inferior part preserving the black color of the remainder of the organs. Its 

 larva is a white maggot, and exists in decaying stumps and logs. It is usually found in the 

 forests in its perfect state in midsummer, and is one of the largest dipterous insects of 

 New- York. 



Syrpliidae. 



MiLEsiA viRGiMENsis. ( Plate xxviii, fig. 3.) 



McscA viRGiNiENsis ( Drury). Milesia ornata ( Fabricius). 

 Eyes black ; front of the head cream-color ; antennae like short hairs ; thorax yellow, 

 with two black rings ; abdomen black, ornamented with yellow rings, every alternate 

 one of which is interrupted in the middle : it is marked with a yellow dot at the 

 base, and terminated with yellow. Legs yellow ; wings dusky. Underside, breast black, 

 with yellow spots : ocelli distinct. 

 It is rather more than three-foui-ths of an inch long ; expansion of wings, 1^. 



