256 DIPTERA. 
macrochete on the hind margins. Legs, including the cox, yellowish-rufous, the middle and hind tibie 
brownish, the tarsi black. Tegule whitish. Wings greyish-hyaline; small cross-vein before the middle 
of the discal cell ; curvature of the fourth vein rectangular; apical cross-vein distinctly concave; posterior 
cross-vein oblique and nearly straight ; first and third veins with short bristles, the first vein over its 
whole length, the third from the base to beyond the small cross-vein. 
Hab. Mexico, Venta de Zopilote in Guerrero 2800 feet (H. H. Smith). 
A single female specimen. 
XANTHODEXIA, gen. nov.* 
Head hemispherical, broader than the thorax; eyes bare, descending nearly to the lower part of the head; 
front broader than the eyes ; frontal band reduced to a very narrow groove, which in the middle is linear 
and at each end is somewhat enlarged triangularly; the trigonal depression on the vertex includes a 
distinct ocellar tubercle; on each side of the frontal groove a row of bristles descends to the root of the 
antenne ; no orbital bristles, Face not carinated ; cheeks somewhat convex ; vibrissal swellings parallel ; 
vibrisse inserted at the oral margin, which is not prominent. Antennz inserted beneath a line drawn 
through the centre of the eyes ; third joint longer than the second; arista distinctly plumose. Proboscis 
short and thick, with large terminal lips; palpi cylindrical. Abdomen elliptical; anal segment shorter 
than the other segments ; first and-seeond segments only with lateral macrochete; on the hind margins 
of the third and anal segments several strong macrochete. Legs slender, though not elongate, with weak 
bristles. Wings as long as the abdomen ; apical cell rather broadly opened a little before the wing’s tip ; 
curvature of the fourth vein with a blunt angle and without appendage, 
1. Xanthodexia sericea. (Tab. VI. figg. 11; 11a, head seen from in front ; 
11 6, head in profile.) 
Tachina sericea, Wiedem. Aussereur. zweifl. Ins. ii. p. 316. no. 64. 
Yellow ; thoracic dorsum and scutellum yellowish-cinereous ; pleure whitish; anal segment, tibic, and tarsi 
black. 
Length 8°5-10 millim. 
Head bright pale ochraceous, the inferior portion of the posterior orbits silvery-white ; antenne yellow, the second 
joint prominent, with black hairs, the third joint three times as long as the second ; arista black, thickened 
in its proximal half; proboscis yellow, with the base blackish ; palpi yellowish, slightly infuscated towards 
the tip. Thoracic dorsum and scutellum with a yellowish-cinereous tomentum and scarcely any trace of 
dark stripes ; pleure whitish-grey, somewhat silvery ; metanotum grey. Abdomen yellow, slightly trans- 
parent, and with silvery-white reflections; a black spot at the base; hind margin of the third segment 
shining black ; anal segment also shining black, but with its front border more or less rufous. Tegule 
yellow. Wings greyish, at the base and along part of the costa yellow, infuscated towards the end of 
the costa ; small cross-vein on the middle of the discal cell; apical and posterior cross-veins straight. 
Hab. Mexico, Acapulco in Guerrero, Atoyac in Vera Cruz, Teapa in Tabasco (H. Z. 
Smith).—BRaziu, 
Three female specimens, 
The identity of the Mexican insect with Tachina sericea, Wiedem., is stated by Prof. 
Brauer, who has been kind enough to compare a specimen with the typical example 
in the museum of Vienna. ‘The type has a plumose arista, a character which Wiede- 
mann seems to have overlooked. 
* §arOds (yellow) ; Dewia, 
