SCATOPHAGA.—HELOMYZA. 351 
Hab. Mexico, Mexico city (H. H. Smith). 
This species is nearly allied to the European S. squalida, Meig., which occurs also 
in North America (mentioned by Say under the name Pyropa furcata); it differs, 
however, in having black stripes on the femora, which are usually wanting in 
S. squalida, though sometimes slightly indicated on the front pair. 
Two species of Scatophaga have been previously described from Mexico :— 
Scatophaga reses, Gig].-Tos, Mem. R. Accad. Scienze di Torino, ser. 2, xlv. (sep.) 
p. 34. no. I. 
cenosa, Gigl.-Tos, loc. cit. no. 2. 
The first-mentioned, as I have already noted, may belong to the species described by 
me (anted, p. 349) under the name of Cordylura rufina. 
Group HELOMYZINZ. 
The insects of this group are characterized by a rather broad front, of which only 
the posterior half is set with bristles; distinct vibrisse; the antenne not elongate, 
often short, with a rounded third joint; the abdomen elliptical, moderately broad. 
In the wings, the auxiliary vein is separated from the first vein, and the inferior 
basal cells are complete. 
In the Central-American collections before me the genus Helomyza only is 
represented. 
HELOMYZA. 
Helomyza, Fallén, Heteromyz. Suec. p. 3 (1820). 
Of this genus I have distinguished four species, which all have blackish markings 
on the wings. 
1. Arista distinctly plumose ; wings with blackish borders to the costa 
and to the veins, but no spots between the veins . . . 2. 
Arista bare or short-haired ; two or more isolated spots between the 
veins. . . 3. 
2. A black stripe on . the fourth vein, forming with the black border of 
the posterior cross-veina T-like mark. . ... . ... . %imiens, Gigl.-Tos. 
The black border of the posterior cross-vein not extended on “the 
fourth vein. . . . punctulata, v. d. Wulp. 
3. Two spots only in the first posterior cell, in addition to ‘the blackish 
markings . .. . . . . . distigma, v.d. Wulp. 
Several spots in nearly all the cells, in addition to the blackish 
markings . 2. 2. - 1 1 ee ee we we ew we + polystigma, v. d. Wulp. 
