216 DIPTERA. ' 
distinctly carinated in the middle ; vibrisse inserted much above the oral margin, which is slightly pro- 
minent, somewhat rufous, and beset with a row of long bristles. Antenne short, inserted below a line 
drawn through the middle of the eyes; basal joints dark rufous; second joint with short bristles; third 
joint brown, one and a half times as long as the second; arista distinctly plumose, thickened at the base. 
Proboscis black, slender, nearly as long as the body, and with rudimentary terminal lips ; palpi rufous, 
small, filiform. Thorax and scutellum black; thoracic dorsum anteriorly greyish, with obsolete black 
stripes. Abdomen ovate, black ; second and following segments with many discal and marginal macrocheete. 
Legs long and slender, black, the knees and sometimes the tibie: dark rufous; tibie with long bristles ; 
foot-claws and pulvilli elongate, the pulvilli yellowish-grey. Tegule brown, with a yellowish margin. 
Wings brownish-grey ; apical cell opened at some distance from the wing’s tip ; small cross-vein a little 
before the middle of the discal cell; curvature of the fourth vein angular but without appendage ; apical 
eross-vein concave ; posterior cross-vein slightly curved. — 
Hab. Mexico, Amula in Guerrero 6000 feet (H. H. Smith). 
Several male specimens. 
A single female example from the same locality agrees in all respects with the 
above description, except the usual sexual differences (a broader front and short foot- 
claws and pulvilli) and the macrochetz on the abdomen being less numerous and more 
regularly arranged on the disc and hind margins of the segments. 
The identity with Mochlosoma validum, Br. & v. Bergenst., is stated by Prof. Brauer 
himself, who has seen a specimen. 
In its general aspect, and also by the very long proboscis, Prosena valida bears a 
striking resemblance to Hystrisiphona niyra, Big., except that the scutellum and 
abdomen are not armed with spines. ) 
3. Prosena tessellans, sp.n,g @. § 9 * fo fh 0 
Blackish ; head whitish, with rufous reflections ; antenne rufous ; abdomen with cinereous and white reflecting 
spots, and with discal and marginal macrochete; legs black, the tibia sometimes piceous; wings 
greyish. 
Length 7-11 millim. 
This species varies in size and in the intensity of the coloration. Head whitish ; front of the male very much 
narrowed behind, the eyes being nearly contiguous on the vertex, that of the female broader than the 
eyes; frontal band black or brown, or even brownish-red, on both sides with several bristles, which do 
not descend beneath the root of the antenne ; cheeks broad, with a brownish-red reflection, which is also 
visible at the oral margin. Antenne short, rufous; second joint with a long and some short bristles ; 
third joint a little longer than the second, usually brown at the tip; arista black, thickened at the base, 
thinly plumose in the middle. Proboscis black, two or three times as long as the head; palpi short, 
rufous. Thorax and scutellum blackish, with more or less distinct cinereous tomentum and beset with 
black hairs and macrochete; in the less obscure specimens (usually females) five black stripes (the three 
median close together) become conspicuous on the thoracic dorsum. Abdomen conical (3) or elongate- 
oval (2), with many discal and marginal macrochete; in the darkest examples it is black, with 
grey and white reflecting spots, in lighter specimens it is cinereous, with black and white -reflections. 
Legs black, sometimes the tibia piceous or even brownish-red ; coxse on the front side with long black 
pile; foot-claws and pulvilli elongate in the male, the pulvilli dark yellowish-grey.. Tegulee yellowish- 
white. Wings greyish-hyaline, with black veins; small cross-vein nearly on the middle of the discal cell ; 
curvature of the fourth vein rectangular and a little rounded ; apical cross-vein distinctly concave ; poste- 
rior cross-vein oblique and very slightly curved, nearly straight. 
Hab. Mexico, Ciudad in Durango 8100 feet (Forrer), ‘Tierra Colorada, Rincon, 
