PROSPHERYSA.—SIPHONA.. 125 
Hab. Mexico, Dos Arroyos 1000 feet, and Tierra Colorada 2000 feet, both in Guerrero 
(1. H. Smith). 
Two female specimens. 
fo #2 
ee 24° of i he eee é 
18. Prospherysa plagioides, sp.n,@. ‘Ji. vee © 
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Blackish ; thorax cinereous, with black stripes; abdomen with grey reflections, and with white front margins 
to the segments; palpi rufous or with a rufous tip ; posterior cross-vein very oblique. 
Length 4-5 millim. 
Head broader than the thorax, greyish-white; front much broader than the eyes; frontal band black; frontal 
bristles on each side in a curved row, two of them descending beneath the root of the antennex ; facial 
bristles mounting to more than two-thirds of the face. Antenne as long as the face; third joint six 
times as long as the second; arista thickened to, or to a little beyond, the proximal half. Proboscis 
black, with the terminal lips rufous; palpi short, pale rufous, or at least rufous at the tip. Thorax 
and scutellum cinereous; thoracic dorsum with four black stripes, the median two of which are linear 
and more distinct. Abdomen conical, truncate at the anus ; first segment black ; the following segments 
black, with grey reflections and white front margins; macrochete only on the hind margins of the 
segments. Legs black, with scattered bristles. Tegule whitish. Wings greyish-hyaline; third vein 
bristly from the base to the small cross-vein, the latter distinctly before the middle of the discal cell; 
curvation of the fourth vein with a blunt angle and without appendage; apical cross-vein concave ; 
posterior cross-vein nearly straight and much more oblique. 
Hab. Mexico, Amula in Guerrero 6000 feet, Cuernavaca in Morelos (H. H. Smith). 
Several female specimens. 
In the neuration of the wings this species approaches the genus Plagia; but the 
bristles on the facial ridges and the very long antenne show that it is better placed 
in Prospherysa. 
SIPHONA. 
Siphona, Meigen, in Illiger’s Magaz. ii. p. 281 (1803). 
This genus is distinguished by the very long and slender proboscis, of which the 
apical half is turned backward. It contains some very common species in Europe; and 
two are here described (and a third noticed) from Central America. With the exception 
of one species from Brazil, Tachina singularis, Wied. (Aussereur. zweifl. Ins. 11. p. 339. 
100), which is a Stphona according to Jaennicke (Neue exot. Dipteren, p. 87), the 
genus has not yet been recorded from any other part of the world. 
1. Siphona futilis, sp.n., ¢ 9. 
Thorax cinereous, without stripes; abdomen rufous, with blackish markings ;. frontal band, palpi, and legs 
rufous; antenne (except sometimes the basal joints) and tarsi black. 
Length 2°5 millim. 
Head yellowish-white ; front broader than the eyes; frontal band pale rufous; frontal bristles inserted on 
black warts; occiput grey. Antenne black; the basal joints showing a tendency to become rufous ; 
third joint rather narrow, three (2) or four (¢)) times as long as the second ; arista nicked, thickened 
in its proximal half, the penultimate joint half the length of the terminal one. Proboscis. black, rufous 
towards the tip; palpi pale rufous. Thorax and scutellum cinereous, without markings, but with 
numerous little black points, on each of which a hair is inserted. Abdomen—{ ¢) nearly cylindrical, 
