70 DIPTERA. 
17. Exorista trivittata, sp.n., ¢. 
Grey ; thorax with three black stripes, on either side of the median stripe a black line; hind borders of the 
abdominal segments, frontal band, antenne, palpi, and legs black. 
Length 10 millim. (that of two of the specimens 6 millim. only). 
Front ochraceous, with brown reflections, on the vertex less broad than the diameter of the eyes ; frontal 
bristles descending on both sides in a single curved row beneath the second antennal joint; face and 
cheeks pale yellow, the median portion of the face whitish ; vibrisse surmounted by some shorter bristles ; 
beard whitish ; pilosity of the occiput pale yellow; eyes densely pilose. Antenne shorter than the face ; 
second joint bristly on its upper part; third joint three times as long as the second ; arista thickened on 
the proximal half, Thorax grey, with three broad black stripes over the whole length ; on either side of 
the median stripe a black line, these lines prolonged behind the transverse suture but disappearing i in the 
more general black coloration of the hind portion of the thorax; scutellum black, with a grey hind border 
Abdomen conical, grey, the first segment and a broad hind border to the following segments black (in 
some positions the third and fourth segments appear black with a narrow white front margin, in others a 
black dorsal line is conspicuous); a pair of macrochate on the hind margin of the second segment and a ~ 
row of macrochete on that of the third and fourth segments; anus shining black, with the male genitals 
somewhat exserted. Middle tibie outwardly with two long bristles and a similar bristle on the inner 
side below the middle; hind tibise outwardly with almost fringe-like bristles ; foot-claws and pulvilli 
elongate, the pulvilli yellowish. Tegule pale yellow. Wings greyish-hyaline, with a slight brownish 
tint along the costa at the base; small cross-vein on the middle of the discal cell; apical cross-vein a 
little concave at its base; posterior cross-vein faintly curved, sometimes nearly straight. 
Hab. Mexico, Orizaba (coll. Bellardi), Atoyac in Vera Cruz, Teapa in Tabasco 
(H. H. Smith). 
Several male specimens. 
18. Exorista nigricauda, sp. n., ¢. 
Thorax grey, with three black stripes, on either side of the median stripe a black line; abdomen black, with 
whitish front borders to the second and third segments; frontal band, antenne, palpi, and legs black. 
Length 5:5 millim. 
Allied to the preceding species (Z. érivittata), and resembling it, but of a much smaller size. The coloration of 
the front is more whitish; the anal segment is black, without a greyish front border, and only laterally 
with a whitish reflecting spot; the tegule are whiter; the third vein and the apical cross-vein are bent 
upwards near their end; the posterior cross-vein is a little concave. 
_ Hab. Mexico, Atoyac in Vera Cruz (H. H. Smith). 
A single male specimen. 
19. Exorista angustata, sp. n., ¢(??). 
Grey; frontal band, stripes on the thorax, hind borders of the abdominal segments, antenne, and legs black ; 
palpi rufous at the tip. 
Length 12 millim. 
Of elongate form. Head whitish; front slightly prominent, scarcely narrowed behind, nearly as broad as the 
eyes ; frontal band with parallel sides; frontal bristles on each side in a curved row, descending beneath 
the end of the second antennal joint; cheeks rather broad, with silvery reflections. Antenne nearly 
as long as the face; second joint short and bristly; third joint narrow, six times as long as the second ; 
arista thickened on the proximal half. Proboscis black, with the terminal lips pale rufous ; palpi 
eylindrical, rufous, black towards the base. Thorax, scutellum, and abdomen grey; thoracic dorsum 
with four black stripes, the median stripes linear, the outer ones interrupted at the transverse suture. 
Abdomen conical; first segment black ; second and third segments with black hind borders and blackish 
