288 DIPTERA. 
Exot. ii. 3, p. 96; Sarcophaga fortipes, Walk. ‘Trans. Ent. Soc. Lond. 
new ser. v. p. 310. 
Phrissopoda lamanensis, Rob.-Desv. Essai sur les Myodaires, p. 335 (Peckia) ; 
Giglio-Tos, 1. c. p. 68. 
plumipes, Rob.-Desv. Essai sur les Myodaires, p. 336 (Peckia); Giglio-Tos, 
l. c. p. 68.—Sarcophaga intermutans, Walk. Trans. Ent. Soc. Lond. new 
ser. v. p. 308. 
immanis, Walk. List of Dipt. Ins. iv. p. 815 (Sarcophaga) ; Giglio-Tos, 1. ¢. 
p. 67. 
ONESIA. 
Onesia, Robineau-Desvoidy, Essai sur les Myodaires, p. 365 (1830). 
In the species of this genus the abdomen is metallic blue or green. From Phrisso- 
poda, of which some species also have a more or less metallic abdomen, and from 
Cynomyia, in which this character is common to all the species, Onesia differs in 
having the curvature of the fourth vein with an obtuse angle and the apical cross-vein 
straight or nearly so. 
One species of Onesia is represented in the Mexican collections before me. 
1. Onesia lucilioides, sp.n., ¢. (Tab. VII. fig. 11, ¢.) | 
Metallic-blue, the thorax with purple, the abdomen with green reflections; head white; antenne, palpi, and 
legs black. 
Length 6 millim. 
In the broad form and the splendid metallic coloration this species, at first sight, resembles a Lucilia; but the 
presence of the macrochete on the abdominal segments shows that it evidently belongs to the genus 
Onesia. The front is black and very narrow (equalling about one-fourth of the transverse diameter of 
the eyes), with nearly parallel sides. Face and cheeks white, with brown reflections; inferior part of 
the cheeks equalling one-third of the longitudinal diameter of the eyes. Antenne black, inserted on the 
median line of the eyes ; third joint three times as long as the second; arista thickened in its basal third 
and plumose to beyond the middle. Proboscis and palpi black. Thorax quadrate, steel-blue, without 
any whitish tomentum or stripes; the hind angles purple; dorso-central bristles distinct. Scutellum 
violet. Abdomen ovate, as long and broad as the thorax, metallic blue, with green reflections, clothed 
with black hair; second segment with lateral macrochete only; a row of macrochete at the hind 
border of the third segment; anal segment with macrochete on the whole surface; hypopygium con- 
cealed. Legs black ; anterior cox with grey tomentum ; femora and tibie with scattered bristles; hind 
tibie slightly curved ; tarsi slender, as long as the tibie ; foot-claws somewhat elongate ; pulvilli yellow. 
Tegule yellowish-grey. Wings hyaline, with a slight greyish tinge; small cross-vein a little before the 
end of the first vein and on the middle of the discal cell; curvature of the fourth vein with an obtuse 
angle; apical cross-vein nearly straight ; posterior cross-vein very slightly undulate. 
Hab. Mexico, Mexico city (H. H. Smith). 
A single male specimen. 
