218 DIPTERA. 
Legs black, rather slender; femora with many bristly hairs; tibiz with some scattered bristles; foot- 
claws and pulvilli elongate in the male, short in the female ; the pulvilli yellowish-grey. Tegule brown. 
Wings greyish-hyaline, the base and costa brownish ; small cross-vein nearly on the middle of the discal 
cell; curvature of the fourth vein with a blunt angle; apical and posterior cross-veins oblique and 
straight. 
Hab. Mexico, Xucumanatlan 7000 feet, and Omilteme 8000 feet, both in Guerrero 
(H, H. Smith). 
as 
Four male and eight female specimens. 
Fat 
. +, 
Bigot has described two species as belonging to the genus Prosena, both from 
Mexico :— 
Prosena maculifera, Bigot, Ann. Soc. Ent. Fr. 1888, p. 264. no. 55. 
obscura, Bigot, |. c. no. 56. 
I have examined the typical examples of both: P. maculifera is a female of Stoma- 
todexia cothurnata, Wiedem.; P. obscura is identical with Rhamphinina anthracina, 
Big., a species included by me in the genus Rhynchodevia. 
One Mexican species of Prosena has also been described by Macquart :— 
Prosena mexicana, Macq., Dipt. Exot., Suppl. 4, p. 231. no. 7, t. 21. f. 12. 
HYSTRICHODEXIA. 
Hystrichodexia, von Roder, Stett. ent. Zeit. 1886, p. 266. 
This genus is characterized by the short antenne, the plumose arista, the carinated 
face, the proboscis as long as, or a little longer than, the head, and nearly the whole 
surface of the abdomen densely armed with strong, or even spinose, macrochete. The 
cheeks are broad, their lower portion being a little shorter than the longitudinal 
diameter of the eyes; the vibrissal swellings are nearly parallel ; the vibrisse are 
inserted at some distance above the oral margin; the antenne are inserted on or a little 
below a line drawn through the centre of the eyes; the frontal band shows several lon- 
gitudinal grooves; behind the vertex are usually some long hairs; in most of the species 
the scutellum is densely beset with erect bristles; the abdomen is ovate; the legs are 
long and slender, the foot-claws and pulvilli elongate in the male; the apical cell is 
opened at some distance before the wing’s tip; curvature of the fourth vein more or 
less angular, usually without appendage. 
To Hystrichodeaia, which has hitherto contained a single representative, H. armata, 
