200 Mr. F. Walker's Characters of uudescrihed Dtptera 



Female. — Black, slender, beset with long bristles, with cine- 

 reous tomentum ; head white in front, behind, and beneath, 

 clothed with white hairs beneath ; frontalia deep black, widening 

 towards the face, with two rows of bristles, which extend to one- 

 third of the length of the face ; facialia without bristles ; epistoma 

 not prominent ; eyes bare ; antennae extending to the epistoma ; 

 third joint linear, slender, about four times longer tlian the se- 

 cond ; arista slender, very much longer than the third joint; 

 thorax with four black stripes ; abdomen elongate-obconical, 

 much longer than the thorax, with three broad black bands, 

 which are dilated in front ; tip black, shining ; legs rather long 

 and slender ; wings brown, rather long and narrow, grey towards 

 the tips and along the interior border ; veins black ; prcubrachial 

 vein forming an extremely obtuse angle at its flexure, from whence 

 it is almost straight to its tip, which joins the costal at a little in 

 front of the tip of the wing and very near the cubital ; the latter 

 is slightly curved, parted by a little less than its length from the 

 flexure of the praebrachial, and by less than its length froin the 

 border ; alulae whitish. 



Length of the body 3^ lines ; of the wings 8 lines. 



South America. 



Genus Trixa, Meig. 



Trixa? sejuncta. 



Foem. — Nigra, setosa, capite subtus cano, frontalihus striatis, 

 facie angusta subretracta, facialibus setosis, antennis rufe- 

 scentibus, articulo 3" piceo aristd nigra crassa pubescente, 

 thorace vix vittato, abdomine longi-ovato tessellato, tibiis 

 ferrugineis, alis cinereis, venis fulvis apice nigris, alulis 

 albidis. 



Female. — Black, setose ; head hoary beneath ; frontalia striated, 

 linear, with a row of bristles along each side ; face narrow, 

 slightly retracted ; facialia with bristles along two-thirds of the 

 length from the epistoma, which is not prominent; eyes bare; 

 proboscis ferruginous ; antennae reddish ; third joint piceous, 

 elongate-obconical, not longer than the second ; arista black, 

 stout, pubescent, rather longer than the third joint ; thorax in- 

 distinctly striped; abdomen elongate-oval, tessellated, spinose ; 

 tibide ferruginous ; wings grey ; veins tawny, black towards the 

 tips ; praebrachial vein emitting a rather long branch and form- 

 ing an obtuse angle at its flexure, slightly curved between that 



