74 DIPTEEA. 



(13*5 millim.) ; the upper part of the front and the vertex clothed not with black but 

 with thin brownish-rufous pile. The abdominal segments beyond the second clothed 

 with an appressed rufous tomentum, mixed with pale-yellow hairs ; along the hind 

 margins the yellow hair becomes more dense, and produces, in an oblique light, the 

 appearance of pale golden-yellow fringes. The tufts of black hair on the sides of 

 segments 3 and 4 are quite conspicuous. The antennas agree with the description, the 

 venation with the figure. 



HIRMONEURA. 



Hirmoneura, Meigen, System. Beschr. ii. p. 132 (1820). 



l. Hirmoneura psilotes, sp. n., $ . 



Brown, with a brownish-yellow pollen ; legs pale rufous ; antennae and palpi rufous wings tinged with pale 



brownish, brownish-yellow along the costa ; eyes glabrous. 

 Length, without the ovipositor, about 13 millim. 



Hab. Mexico (Sumichrast). 



Proboscis rufous, short, the large lips but little projecting outside of the oral 

 opening ; last joint of the palpi long, cylindrical, pale rufous, closely applied to the 

 facial orbit of the eye and almost reaching the antennas ; antennas rufous, beset with 

 rufous hair; face and front densely covered with a yellowish-grey pollen; the face 

 beset with pale rufous hairs, the front with black hairs mixed with rufous ones, the 

 latter especially visible in front of the ocelli ; front nearly parallel, the vertex very 

 little narrower ; eyes glabrous. The brown ground-colour of the thoracic dorsum is 

 modified by a brownish-yellow pollen and yellowish hairs, which cover its surface ; the 

 hairs longer on its sides ; pleurae and sternum more grey, with paler yellow hairs ; 

 post-alar callosities reddish ; scutellum brown. The abdomen, like the thorax, derives 

 its colouring from a brownish pollen, which is darker on the posterior half of segments 

 2, 3, 4 (these segments thus showing slight traces of darker cross-bands) ; the base with 

 longer pale yellowish-rufous hairs ; the posterior half of segment 2, as well as the two 

 following segments, beset with short, semierect black hairs; the three following 

 segments (5-7) are'shorter and narrower and end in an ovipositor, which, so far as I 

 can see, consists of a short tube, longitudinally split in two. Legs pale rufous ; hind 

 femora slightly brownish at the tip ; hind tarsi brown. Wings with a pale brownish 

 tinge, more yellowish along the costa ; veins on the antero-proximal half rufous, on the 

 remainder of the wing dark brown ; venation like that of the European H. obscura, 

 only the handle of the fork of the third vein is straighter. A single female in Prof. 

 Bellardi's collection. 



The only species of Nemestrinidse hitherto described from Central America is Hirmo- 

 neura brevirostris, Macq. (Dipt. Exot. Suppl. i. p. 101, t. 20. f. 1), which has pubescent 

 eyes, hyaline wings, &c. 



^cO^^^^i^ y<j^a QUI 



