54 DIPTERA. 
part ; third joint narrow, rounded at the end, three times as long as the second; arista thickened to nearly 
half its length; palpi rufous. Thoracic dorsum and scutellum ochraceous, partly with a peculiar violet 
tint, the shoulders more brightly ochraceous ; the thorax with four black stripes over its whole length, 
and sometimes with a fifth stripe appearing anteriorly in the middle. Abdomen cinereous, with the same 
violet tint as the thorax and with brown reflections; the first segment, a narrow border on the hind 
margins of the following two segments, the anus, and the ventral face black; macrochetz on the hind 
margins of the second and third segments, and a pair of smaller size at some distance before these margins 
(in some specimens these latter are absent) ; anal segment, as usual, with several macrochete. Legs black ; 
on the outside of the hind tibie the bristles are fringe-like and a little beneath the middle a longer bristle 
appears between them ; foot-claws and pulvilli elongate in the male; pulvilli greyish-testaceous. Tegule 
cinereous, with a yellowish margin. Wings grey, usually infuscated at the base and along the costa to the 
end of the second vein ; small cross-vein a little before the middle of the discal cell; curvation of the 
fourth vein nearly rectangular ; apical cross-vein somewhat concave; posterior cross-vein slightly curved. 
Hab. Mexico (coll. Bellardi), Chilpancingo 4600 feet, Amula 6000 feet, Xucuma- 
natlan 7000 feet, Omilteme 8000 feet, all in Guerrero, Atoyac in Vera Cruz, Teapa in 
Tabasco (H. H. Smith), Temax in North Yucatan (Gaumer); GuaTEMaLa, Zapote 
(Champion). 
Many specimens of both sexes. 
_- Ina splendid variety, of which I have before me several examples of both sexes, the 
thorax is much more obscure, the ochraceous tomentum being reduced to a small 
humeral spot, and the abdomen has a metallic green or blue coloration. Mr. Smith, 
who collected a large series of this variety, has noted the coloration of living spe- 
cimens as follows :—*“ thorax brilliant green with black marks; abdomen blue-green ; 
head golden-yellow, vertex green, frontal stripe velvety brown.” 
Mystacella violacea seems to be a common insect in Mexico, and it is also represented 
in the collection of Prof. Bellardi. 
It is possible that Hurigaster commetans, Walk. (Trans. Ent. Soc. Lond. n. ser. v. 
p. 299), belongs to the same species. The description is applicable, but the peculiar 
violet tint which distinguishes the species is not mentioned, nor is it stated whether the 
eyes are hairy or not; the genus Hurigaster (as it is adopted by Macquart) includes 
species with bare, as well as others with hairy, eyes. 
4. Mystacella lineata, sp. n., d 2. 
Cinereous with a violet tint; frontal band, antennae, legs, four slender Jines on the thorax, and the hind 
margins of the abdominal segments black ; palpi rufous ; wings nearly hyaline. 
Length 10 millim. 
Very closely allied to the preceding species. The front is narrower in the male, dark cinereous, sometimes 
with a bluish tint. The antenne are wholly black and longer, the third joint four times as long as the 
second. The stripes on the thorax are much narrower, linear. The abdomen has the same tendency to 
become blue or green. The wings are not infuscated at the base and along the costa, only the veins are 
bordered by a dilute brownish tint. 
Hab. Mexico, Teapa in Tabasco (H. H. Smith). 
One male and two female specimens. 
