MYOCERA:—TROMODESIA. 237 
1. Myocera rava, sp.n., 2. 
Cinereous ; thorax with blackish stripes; antenne and legs black; cheeks and palpi rufous. 
Length 7 millim, 
Head cinereous, the front with blackish, the cheeks with rufous, reflections ; frontal band brown, broader than 
the lateral portions ; face shorter than the front, sharply carinated. Antenne black, their basal joints 
more or less rufous ; second joint bristly ; third joint twice as long as the second; arista thickened at 
the base. Proboscis black, the terminal lips somewhat rufous; palpi pale rufous, slightly thickened 
towards the tip. Thorax and scutellum cinereous; thoracic dorsum, before the transverse suture, with 
several black stripes, which, however, are not always visible, the three median stripes linear. Abdomen 
ovate, cinereous ; the first segment and the hind borders of the following segments with blackish reflec- 
tions, which, in some specimens, are less conspicuous or even wholly absent ; second and following segments 
with marginal macrochetz, the hairs and macrochet arising from black points. Legs black; middle 
tibice with some long bristles; hind tibie with bristles of unequal length ; foot-claws and pulvilli short. 
‘Tegule yellowish-white. Wings brownish-grey; apical cell ending nearly in the wing’s tip; small cross- 
vein on the middle of the discal cell; apical cross-vein usually a little concave; posterior cross-vein 
slightly curved. 
Hab. Mexico, Ciudad in Durango 8100 feet (Forrer), Omilteme in Guerrero 8000 
feet (H. H. Smith). | 
Six female specimens. 
This species seems to possess all the characters of the genus Myocera; but male 
examples are required to make sure of the correctness of this determination. 
One species of this genus has already been described from Mexico :— 
Myocera simplex, Bigot, Ann. Soc, Ent. Fr. 1888, p. 266. no. 68. 
The typical example, which I have seen, is in a bad state of preservation, and I am 
not able to give an ample description; I can only state that it belongs to quite a diffe- 
rent species from Jf. rava. 
TROMODKESIA. 
~ Tromodesia, Rondani, Dipt. Ital. Prodr. i. p. 87 (1856), & v. p. 144 (1862). 
Head hemispherical ; front not prominent, narrower than the eyes(@); frontal band narrow, on each side 
with a row of bristles; orbital bristles absent; eyes bare, descending to near the lower part of the head ; 
face much shorter than the front, retracted and slightly concave, with inconspicuous antennal grooves, 
and without any indication of a median carina; vibrisse inserted just at the oral margin. Antenne 
slender, shorter than the face, inserted distinctly below a line drawn through the centre of the eyes ; 
third joint somewhat longer than the second ; arista plumose only in its proximal half. Proboscis rigid, 
a little longer than the head, with well-developed terminal lips; palpi cylindrical, slender. Abdomen 
conical ; first and anal segments shorter than the two median segments. Legs elongate; front tarsi longer 
than the tibiee ; hind tibiee with scattered bristles. Wings scarcely longer than the abdomen ; apical 
cell opened at a short distance before the wing’s tip; curvature of the fourth vein with a blunt angle 
and without appendage. 
