HELOMYZA. 300 
lateral bristles. Legs rufous, tips of the tibiee and the last three joints of the tarsi blackish ; hind tibis 
with an indistinct brown ring near the base; femora rather robust, hairy beneath, the first and third 
pairs each with a row of bristles on the upperside; tibia with a preapical bristle. Halteres pale 
rufous. Wings greyish, with a row of short costal bristles, and with a blackish costal border, covering 
the mediastinal cell and from there extended to the tip of the wing, where it becomes narrower, to the 
end of the fourth vein; the cross-veins bordered with black; a spot on the fourth vein beyond the 
posterior cross-vein, a rounded dot between the second and third veins, just above the small cross-vein, 
and two similar dots between the third and fourth veins. Small cross-vein a little beyond the end of the 
first vein and beyond the middle of the discal cell; posterior cross-vein straight and slightly oblique. 
Female. Differs from the male in having the abdomen pointed towards the apex, the arista shortly plumose, 
and the legs more slender and less hairy ; the femora have a brown spot on the upperside near the tip, 
and the tibia dark rings near the base; the markings of the wings are similar, only the blackish dot 
between the second and third veins is wanting. 
Hab. Mexico, Amula 6000 feet, Xucumanatlan 7000 feet, and Sierra de las Aguas 
Escondidas 9500 feet, all in Guerrero (H. H. Smith). 
A single male specimen from the last-mentioned locality, and a female from each of 
the others. 
Notwithstanding the differences between the two sexes, I have no doubt that they 
belong to the same species. 
4. Helomyza polystigma, sp.n., ¢. (Tab. IX. fig. 6, wing.) 
Testaceous ; a blackish stripe on the pleure ; wings with a blackish border to the costa and to the cross-veins, 
and numerous spots in all the cells. 
Length 4°5 millim. 
Allied to the preceding species (H. distigma), but smaller and differing from it in the markings of the 
wings. Face, cheeks, and anterior portion of the front yellowish, with a white reflection ; front poste- 
riorly rufous with some brown points; frontal bristles as in H. distigma; a black spot on each side 
between the orbits and the root of the antenn#. Antenne rufous; third joint rounded, blackish on the 
upperside ; arista with very short hairs. Proboscis rufous (the palpi inconspicuous in the specimens 
examined). Thorax and scutellum brownish-testaceous, the shoulders yellowish, beneath them on the 
partly cinereous pleure a blackish stripe ; scutellum with four bristles. Abdomen brown, the segments 
with narrow black borders. Femora blackish; tibie rufous, with black tips; first joint of the tarsi 
rufous, the following joints blackish ; tibiee with a preapical bristle. Halteres yellow. Wings greyish ; 
a blackish border along the costa, round the tip, and on the cross-veins, and blackish spots of different 
sizes in all the cells; the costa with a row of short bristles; small cross-vein nearly under the end of the 
first vein and on the middle of the discal cell. 
Hab. Mexico, Sierra de las Aguas Escondidas in Guerrero 9500 feet (Hl. A. Smith). 
Two female specimens. 
Dr. Giglio-Tos in his work on Mexican Diptera (Mem. R. Accad. delle Scienze di 
Torino, ser. 2, xlv.) also includes the following species among the Helomyzine :— 
Diplocentra gibba, Fabr. Syst. Antl. p. 297. 70 (Musca); Wiedem. Aussereur. 
zweifl. Ins. ii. p. 586. 1 (Helomyza); Macquart, Dipt. Exot. ii. 3, p. 198, 
t. 25. fig. 9,10 (Curtonotum); Schiner, Dipt. Novara Reise, p. 237. 18 
(Curtonotum) ; Gigl.-Tos, loc. cit. (sep.) p. 36. no. 4. 
BIOL. CENTR.-AMER., Dipt., Vol. II., September 1897. 22 
