238 DIPTERA. 
It is not without doubt that I include Z. hemorrhoidalis, Big., in Tromodesia, Rond., 
as I am not at all acquainted with the only European species of the genus, 7’. vibri- 
pennis, Rond., from Italy. The above-mentioned generic characters are taken from 
the Mexican species, but seem to agree tolerably well with those given by Rondani in 
his Prodromus (J. ¢.). 
f 
yn & Le 
Ay \ 
, e ° 5 i Je si te 
1. Tromodesia hemorrhoidalis. (Tab. V. figg. 8; 84, head.) Dt ce thee 
Tromodesia hemorrhoidalis, Bigot, Ann. Soc. Ent. Fr. 1888, p. 267. no. 69. poy 
Cinereous; frontal band, thoracic stripes, hind margins of the abdominal segments, antenna, proboscis, and 
legs black ; palpi and anus rufous. 
Length 9 millim. 
Head greyish-white ; frontal band narrower than the lateral portions ; occiput grey; vibrisse accompanied by 
shorter bristles. Antenne blackish; second joint with a long bristle; third joint nearly twice as long as 
the second; arista thickened and plumose in its proximal half; palpi pale rufous. Thorax and scutellum 
cinereous ; thoracic dorsum with four black stripes—the median ones linear, the outer stripes broader and 
less distinct ; scutellum flattened. Abdomen cinereous, with a rough pile; first segment almost wholly 
black ; the second and third segments with ill-defined black hind borders ; anal segment, seen from above, 
with a rufous tip—laterally the rufous colour is extended nearly over the whole segment and even on the 
hind margin of the preceding one; true macrochete are only on the hind margins of the segments. 
‘Legs black; the cox and the femora on the outside with a grey tomentum; middle tibie with some 
bristles ; hind tibiee with several bristles of unequal length; the front tarsi have short foot-claws and 
pulvilli (the middle and hind tarsi are broken off in the unique example). Tegule whitish. Wings 
greyish ; small cross-vein on the middle of the discal cell; apical cross-vein slightly concave ; posterior 
cross-vein somewhat curved. 
Hab. Mexico (coll. Bigot). 
qo. 
The description is made from a female specimen, which M. Bigot has been kind 
enough to send me for examination. | 
STOMATODEXIA. 
Stomatodecia, Brauer & v. Bergenstamm, Denkschr. der kais. Akad. der Wissensch. Wien, lvi. 
p. 125 (1889). 
Face perpendicular, not carinated ; oral margin slightly prominent; front in the male narrowed behind, in the 
female broad, with nearly parallel sides ; frontal bristles descending as far as the root of the antenne; in 
the female on each side a pair of orbital bristles; eyes bare; vibrissal swellings divergent towards the 
oral margin; two long vibrisse at a short distance above the oral margin; the lower part of the cheeks 
equalling one third of the longitudinal diameter of the eyes, beneath with a row of hairs or bristles. 
Antenne elongate, inserted above a line drawn through the centre of the eyes ; third joint three times as 
long as the second ; arista moderately long-plumose. Proboscis longer than the head, slender, its terminal 
lips well developed, but small; palpi elongate, cylindrical or filiform. Abdomen conical ( ¢ ) or elongate- 
oval (2); macrochete only on the hind margins of the segments. Legs long and slender, with scattered 
bristles ; foot-claws and pulvilli elongate in the male. Apical cell opened at or somewhat above the wing’s 
tip ; curvature of the fourth vein angular, but without appendage ; posterior cross-vein beyond the middle 
of the apical cell. 
This genus is allied to Prosena, but differs from it by the shorter proboscis and by 
- the face not being carinated. 
