XANTHACRONA.—PTEROCALLA. 393 
This genus is closely allied to Myennis, Rob.-Desv., but differs from it in having the 
second vein more strongly curved, and the scutellum with two (instead of four) bristles, 
as well as in the rufous coloration. 
1. Xanthacrona bipustulata, sp. n.,¢. (Tab. X. figg. 29; 29a, head in 
_ profile.) 
Rufous ; scutellum with two black spots; abdominal segments with brownish hind-borders ; wings hyaline, 
the costa and apex bordered with yellow and brown, a brown oblique band over the cross-veins. 
Length 5 millim. 
- Rufous, the head yellowish, the pleure and abdomen slightly shining. Antenne, proboscis, and palpi 
rufous. Thoracic dorsum with greyish dust; scutellum swollen, especially on a shining black spot in 
each side. Hind-borders of the abdominal segments brownish. Legs yellowish-rufous. Halteres yellow. 
Wings hyaline, with a rather broad yellow costal border, which covers the subcostal cell and is prolonged 
at the tip of the wing to beyond the fourth vein, where it is infuscated and terminates in a point; at the 
end of the auxiliary vein is a brown spot, and there is a similar spot at the end of the first vein; in 
the subcostal cell, above the small cross-vein, is a small, oblique, brownish stripe; the base of the first 
basal cell, the basal half of the cubital cell, and a cross-band obliquely covering the cross-veins, are also 
brownish. 
Hab. Mexico, Presidio de Mazatlan (Forrer). 
A single female specimen. 
PTEROCALLA. 
Pterocalla, Rondani, Studi Entom. p. 83 (1848). 
This interesting genus is represented in the Mexican collections before me by five 
_ species, of which three are treated as new :— 
1. Apical portion of the wings yellowish; the fuscous portion without black 
stripes or dots; first basal cell with a row of hyaline spots. . . . ~ fenestrata, v. d. W. 
Apical portion of the wings not yellow ; the fuscous portion reticulated 
or with many black stripes and dots; no hyaline spots in the first 
basalcell . 2 0. ee ee ee 
2. The wings with four white eye-like spots before the tip—one in the cubital, 
and three in the first posterior cell,—the eye-like spots placed in an 
oblique quadrangle; discal cell without black stripes or dots . . . . guadrata, v. d. W. 
The wings with three white eye-like spots before the tip—one in the 
cubital and two in the first posterior cell; discal cell spotted or 
reticulated. 2 6 6 2 ee et 
3. Cubital cell without black spots beyond the eye-like spot; the end only of 
the second vein infuscated . 2. ee 6 © th te et 
Cubital cell with one or more black spots beyond the eye-like spot . . . 4, 
4. End of the second vein not infuscated ; cubital cell with a single black spot 
beyond the eye-like spot; the fuscous portion of the wings with black 
stripes and dots (in the male the central portion of the wings is much 
BIOL. CENTR.-AMER., Dipt., Vol. IL., September 1899. 3 
ocellata, Wiedem. 
