HYSTRICIA. 13 
Tegule brown, with a narrow yellowish margin. Wings brownish-grey ; the base and the costa fuscous, 
less obscure, however, beyond the small cross-vein and the end of the first vein; small cross-vein on the 
middle of the discal cell; apical and posterior cross-veins oblique and a little curved. 
Hab. Mexico, Medellin near Vera Cruz (H. H. Smith). 
A single female specimen, captured in January 1888. 
3. Hystricia ambigua. (Tab. I. fig. 7.) 
Aystricia ambigua, Macq. Dipt. Exot., Suppl. iv. p. 172. 9°. 
? Hystricia ambigua, Williston, Trans. Am. Ent. Soc. xiii. p. 298’. 
Face and cheeks pale ochraceous, almost whitish ; oral margin not prominent; front cinereous, narrowed 
behind, especially in the male; median band black; pilosity of the front yellowish-grey, that of the 
cheeks, chin, and occiput clearer ; frontal bristles rather long and stout, descending on both sides to a 
little beneath the root of the antenne and there placed closer together; vibrissw distinctly above the oral 
margin, and surmounted by some smaller bristles ; moreover, there are two or three bristles at the chin. 
Antenne black, with some cinereous tomentum ; second joint with several bristles ; third joint broader, 
about as long as the second, outwardly convex, rounded at the end; arista distinctly three-jointed, thick- 
ened to beyond the middle. Proboscis shining black; palpi ochraceous, broad, and with short black 
bristles towards the end. Thorax and scutellum greyish-yellow, with a dense pilosity of the same colour ; 
on the thorax are indistinct dark longitudinal stripes and weak bristles ranged in longitudinal rows. 
Abdomen shining, bluish-black, densely beset (like the scutellum) with black spines. Legs black; front | 
femora outwardly with light grey tomentum; at the underside of the femora and at the outside of the 
tibie are several bristles, those of the intermediate and posterior tibie being longer and stouter; claws 
and pulvilli yellow, the claws with black tips. Tegule greyish, with a yellow margin. Wings grey, at 
the base and along the costa yellowish; veins testaceous ; curvature of the fourth veln with an acute 
angle ; small cross-vein on the middle of the discal cell ; posterior cross-vein almost straight. 
Length 12°5-16 millim. 
Hab. Norra America, Colorado 2.—-Mexico ! 2, Orizaba (H. H. Smith & F. D. Godman); 
GuatemaLa, San Gerénimo (Champion) ; Costa Rica, Rio Sucio, Cache, Volcan de lrazu 
6000 to 7000 feet (Rogers). 
Several specimens of both sexes. 
4, Hystricia cyaneiventris. 
Hystricia cyaneiventris, v.d. Wulp, Comptes Rendus Soc. ent. Belg. xxxviil. p. cexci’. 
Hab. Mexico, Guanajuato (Dugés 1) 
A male specimen in the Royal Museum at Brussels. 
I here give a translation of my description (/. ¢.):— 
Head sericeous, pale cinereous ; front somewhat prominent, narrowed behind, with a blackish longitudinal 
band which is narrower than the cinereous sides; frontal bristles in a single row, descending about 
as far as the second joint of the antennew; vibrisse at a little distance from the oral margin, and 
surmounted by some smaller bristles; cheeks broad; occiput densely beset with yellowish hairs, and at 
the orbits of the eyes with black bristles. Eyes densely clothed with yellowish pile. Antenne black ; 
second joint clothed with white tomentum; third joint twice as long as the second. | Proboscis dark 
brown; palpi fulvous. Thorax metallic green; the front half with cinereous tomentum and four longi- 
tudinal black stripes; on the pleure the ground-colour for the greater part covered with cinereous 
tomentum. Scutellum and abdomen shining bluish-black, nearly steel-blue; abdomen oval, convex, 
