388 Professor Williston on the 



5, Heteroneura valicla, n. sp. (PL XIII., fig. 136, wing.) 



^ , $ , Head, including the antennce, proboscis, and occiput, 

 light-yellow. Arista black, pubescent. Thorax Hght-yellow, 

 mesonotum on the sides and behind, and the scutellum, brown or 

 black, shining ; the yellow extends as a broad stripe to or beyond 

 the suture. Abdomen black or dark-brown, its base, the ovi- 

 positor, and the hypopygium yellow. Legs yellow ; middle tibi« 

 with a stout spur and a preapical bristle. "Wings cinereous 

 hyaline ; penultimate section of the fourth vein as long as the last 

 section of the fifth vein. Length 2|^ mm. 



Numerous specimens. St. Vincent. 



6. Heteroneura lumbalis, n. sp. 

 ^ , $ . Differs from H, valida in the mesonotum being wholly 

 yellow before the middle, the scutellum and posterior part 

 wholly black. The arista is distinctly longer pubescent, almost 

 short plumose. The wings are a little more darkly tinged. 

 Length 2^ mm. 



Numerous specimens. St. Vincent. 



Trigonometopus. 

 Macquart, Hist. Nat. Dipt., ii., 419, 1835. 



1. Trigonometopus rotundicornis, n. sp. (PL XIII., 

 fig. 137, head of $ .) 



^ . Head triangular, the face very much receding ; front plane, 

 horizontal, with three pairs of bristles reaching two-thirds of the 

 distance to the root of the antennae. Eyes longitudinally oval. 

 Antennae porrect, the first two joints short, the third rounded, not 

 longer than broad. Face on either side with a slender groove, 

 running from the root of the antennae to the back part of the 

 cheek. Proboscis with large labella ; palpi slender. Thorax 

 elongate ; mesonotum flattened, with bristles in the middle nearly 

 to the anterior margin ; scutellum flattened, semi-oval, with four 

 bristles. Abdomen oval, depressed, composed of six segments. 

 Legs rather stout ; front femora with a row of bristles below ; hind 

 tibife with a preapical bristle. Auxiliary and basal cells distinct. 

 Arista bare. Sides of the cheeks with a row of long bristles. 

 Yellow, opaque. Front a little darker coloured, with black hair. 

 Antennae reddish-yellow. Face light-yellow. Sides of the frontal 

 pi'ojection somewhat brownish Mesonotum ferruginous, darker 



