CALODEXIA. 257 
CALODEXIA, gen. nov.* 
Head hemispherical; front not prominent, in the male very narrow, in the female as broad as the eyes; face 
perpendicular, not carinated ; cheeks narrow, their lower portion equalling no more than a fifth of the 
longitudinal diameter of the eyes; vibrissal swellings parallel or even somewhat divergent towards the 
oral margin, the vibrisse inserted nearly or quite at the margin. Eyes bare. Antenne elongate, their base 
in a line with the centre of the eyes ; third joint much longer than the second; arista plumose. Proboscis 
short ; palpi cylindrical or slightly thickened towards the tip. Abdomen elongate-conical ; the first three 
segments of equal length, the anal segment shorter; discal and marginal macrochete or marginal ones 
alone. Legs of moderate length, with weak bristles; the tarsi usually not longer than the tibiee. Wings 
as long as the abdomen ; apical cell opened nearly at the wing’s tip; curvature of the fourth vein angular 
but without appendage. 
The species, three in number, of this new genus are very elegant flies. Some of 
them resemble Cholomyia in general aspect and coloration (a partly white, partly black 
thorax, and a yellow abdomen with black portions); but they differ generically by the 
legs in the male not being unusually elongate, and by the eyes descending lower on 
each side of the head. The three species may be distinguished in the following 
manner :— 
1. Eyes descending fully to the lower part of the head; abdomen 
with discal and marginal macrochetz ; larger species (length 
10 millim.) . . ..... . . majuscula, v. d. Wulp. Of 
Eyes not fully descending to the lower part of the head ; abdomen 
with marginal macrochetz only; smaller species (no longer 
than6millim.). 2. 2... 1. 2 1 1 ee ee ee 
2. Legs yellow ; foot-claws and pulvilli elongate in the male. . . calceata, v. d. Wulp. 
Legs black ; foot-claws and pulvilli short . . . . . . . . obscuripes, v. d. Wulp. 
1. Calodexia majuscula, sp.n.¢. (Tab. VI. figg. 12; 12a, head.) 
Head silvery-white ; thorax yellowish-grey, with black stripes; antenne rufous, blackish towards the tip ; 
abdomen yellow, with black hind borders to the segments; proboscis, palpi, and legs yellowish-rufous, 
the tarsi black. 
Length 10 millim. 
Front narrow, with nearly parallel sides ; frontal band black, linear; the lateral portions of the front yellowish, 
with silvery-white reflections; face, cheeks, and posterior orbits silvery-white ; eyes large, fully descending 
to the lower part of the head; beard white; vibrissal swellings divergent towards the oral margin, the 
vibrissee at a short distance above the margin. Antenne a little shorter than the face, rufous, the third 
joint gradually becoming blackish towards the tip. Proboscis and palpi pale rufous; the palpi small, 
cylindrical, slightly curved upwards. Thorax and scutellum yellowish-grey; thoracic dorsum with four 
black stripes—the median stripes linear, the outer ones much broader; plearw grey; scutellum black. 
Abdomen yellowish-rufous, laterally and on the ventral surface somewhat transparent ; hind borders of 
the segments and a dorsal band black ; discal and marginal macrochete present, the discal ones arising 
from black points; anus (seen laterally) obliquely truncate. Legs yellowish-rufous, the middle and hind 
tibia brownish, the tarsi black; front tarsi scarcely longer than the tibie; foot-claws and pulvilli short. 
* xadds (elegant); Dexia. 
BIOL. CENTR.-AMER., Dipt., Vol. IT., Ju/y 1891. 21 
