148 | DIPTERA. 
of its length. The thorax (which in the single specimen before me is somewhat damaged by the pin) 
seems to have four black stripes; scutellum black, with the lateral and hind border whitish-grey. 
Abdomen subelliptical, flattened; first segment black, shorter than the following segments, which are 
grey on the anterior and black on the posterior half, the colours being rather distinctly separated, the 
grey portions, however, having sometimes a dark reflection ; discal and marginal macrochete present 
and very long. Legs black ; hind tibie outwardly with several bristles, one of which (below the middle) 
is longer than the others; foot-claws and pulvilli elongate. Tegule yellowish-grey. Wings greyish- 
hyaline; small cross-vein a little before the middle of the discal cell; curvature of the fourth vein with a 
blunt angle; apical cross-vein oblique, nearly straight ; posterior cross-vein distinctly curved. 
Hab. Costa Rica, Rio Sucio (Rogers). 
A single male specimen. 
15. Hypostena immunda, sp. n., ¢. 
Black, including the antenna, palpi, and legs ; face and sides of the front yellowish; thorax whitish, with four 
black stripes; abdomen with greyish reflecting spots ; wings brownish. 
Length 6-8 millim. 
Closely allied to H. pilosa (antead, p. 144), but differing from it in the wings being brownish, especially on the 
costa and along the veins; the posterior cross-vein is more curved; the cheeks are narrower, and the eyes 
descend much lower; the thoracic stripes are distinct, even behind the transverse suture; the pile of the 
abdomen is less dense; the bristles of the hind tibiee are much shorter; and the pulvilli are yellowish.. 
Hab. Mexico, Atoyac in Vera Cruz, Teapa in Tabasco (H. H. Smith). 
Two male specimens. 
16. Hypostena minima, sp. n., c. 
Blackish ; head white; thorax anteriorly grey with four black stripes; abdomen shining black, with a whitish 
front border to the second and following segments; palpi rufous, at least towards the tip; wings 
brownish. 
Length 4-6 millim. 
Front not prominent, a little narrower than the eyes; frontal band black, as broad as the lateral portions ; 
frontal bristles descending as far as the end of the second antennal joint; face perpendicular; cheeks 
narrow, the eyes almost descending to the inferior part of the head; vibrisse inserted quite at the 
oral margin. Antenne black, a little shorter than the face; third joint three or four times as long as the 
second; arista thickened in its proximal third. Thorax black, anteriorly and at the sides with some 
grey tomentum ; before the transverse suture are four black stripes at equal distances from each other ; 
scutellum black, with grey tomentum. Abdomen conical, convex, shining black, with a white reflecting 
spot at the front border of the second and following segments, the reflecting spots usually interrupted in 
the middle by a black dorsal stripe; discal and marginal macrochete present; ventral surface brownish- 
black, more or less with whitish incisions. Legs black; middle and hind tibisee with some rather long 
bristles below the middle; foot-claws and pulvilli elongate, the pulvilli yellowish. Tegule yellowish-grey. 
Wings brownish, more intensely so towards the costa and along the veins; small cross-vein on or a little 
before the middle of the discal cell; apical cross-vein straight; posterior cross-vein slightly curved 
inward. 
Hab. Muxico, Teapa in Tabasco (H. H. Smith). 
Three male specimens. 
17. Hypostena albocingulata, sp. n., ¢. 
Shining black; thorax grey, with four black stripes; head, pleurm, and two transverse bands on the abdomen 
