140 DIPTERA. 
HYPOSTENA. 
Hypostena, Meigen, System. Beschr. europ. zweifliigl. Ins. vii. p. 239. 39 (1838). 
As characterized by its author, this genus is not clearly defined. This may be 
proved by the following statements :— 
1. According to the description (J. ¢.) and figure (tab. 71. f. 5), its species, especially 
H. procera, Meig., should have no discal macrochete on the abdominal segments 
. (Schiner, Fauna Austriaca, Dipt. i. p. 537, however, has amended this, as Tachina 
cylindracea, Zett., which is considered by him as identical with H. procera, shows 
discal as well as marginal macrochete). 
2. In the analytical table (/. c. p. 178) Hypostena is enumerated among the genera 
with the apical cell opened, which is conformable with fig. 1 of tab. 71; but in the 
description of the genus (/. c. p. 239), Meigen says: “ Mittelzelle (apical cell) an der 
Fliigelspitze geschlossen, stiellos.” 
In general, we may say that the species of the genus Hypostena, in common with 
those of Myobia and Polygaster, have a Dewxia-like aspect owing to the cylindrical or 
conical shape of the abdomen and the elongate legs. The apical cell is narrowly 
opened near the wing’s tip; the eyes are bare (in H. obwmbrata, ¢, microscopical 
pubescent); the third joint of the antenne is three or more times as long as the second; 
and the arista (except in H. concinna) is usually without pubescence. 
Several species from Central America apparently belong to Hypostena, and they may 
be distinguished as follows :— 
1. Abdominal segments with discal and marginal macrochete . 2. 
Abdominal segments with marginal macrochete only . . . 17. 
2. Cheeks broad, the eyes not descending beneath the tip of the 
antemne ... . soe ee 3. 
Cheeks narrow, the eyes descending to near the lowest part of 
thehead . . 2... . ~ ee ew 18, 
3. Thoracic dorsum with two broad black bands wee ew ww 
Thoracic dorsum with four black stripes. . . . . . . . 6. 
4, Palpiblack . 2. 2. 1. 1 1 ww 1 ew ww... leucophea, v. a. Wulp. 
Palpirufous. . . 2. 2... eee OB 
5, Aristabare . 2... . 2 1 1 we ww... . Blandita, v. d. Wulp. 
Arista pubescent . . . . - + concinna, v. d. Wulp. 
6. Pale ochraceous; the abdomen with a black dorsal stripe, 1 narrow 
black hind borders to the segments, and a yellowish pile . elegans, v. d. Wulp. 
Blackish ; the abdomen with white or yellow portions, but the 
black colour always prevailing, and the hairs black . . . 7, 
7. Abdomen laterally yellow and transparent . . . . . obumbrata, v. d. Wulp. 
Abdomen neither transparent nor yellow, at the most with 
some rufous or yellowish tint on the sides of the second and 
thirdsegments . . . . . . . 
