STENOPTERINA,—RIVELLIA. | 381 
Several specimens of both sexes. They all belong to the dark form mentioned in 
Léw’s description. The femora are steel-blue, with scarcely any indication of rufous 
colour at the tip; the tibie and tarsi are reddish-brown, sometimes blackish. The 
brown stripe, covering the first basal cell, is often at its base more or less extended 
over the second basal cell. The ovipositor of the female is flattened and brown, with 
a thin, rufous terminal joint. 
Léw presumed (J. c. p. 98) that his 8. cwrulescens might be conspecific with Herina 
mexicana, Macq.*, and I have no doubt that this is the case. Macquart’s short 
description, though taken from an imperfect specimen, is fully applicable, and his 
figure of the wing docs not show any discrepancy of importance. 
2. Stenopterina alligata, sp.n.,¢. (ab. X. fig. 7, wing.) 
Steel-blue; thoracic dorsum black, with indistinct grey stripes; legs brownish-red; halteres black; wings 
subhyaline, an apical border and a large space, connected with the border of the posterior cross-vein, brown, 
Length 9 millim. 
Closely allied to S. meaicana, and agreeing with it in most of its characters. The thoracic dorsum, however, 
is not metallic, but black, with indication of greyish stripes. Wings with a large brown patch extending 
from the base to beyond the small cross-vein—including the mediastinal cell, the first and second basal 
cells, and the greater part of the discal cell,—and connected with the brown border of the posterior 
cross-vein ; there is no continuous costal border, but a separate brown apical spot ; the mediastinal cell is 
longer than in S. meazcana. 
Hab. Mexico, Paso del Macho (fége). 
Two female specimens. 
RIVELLIA. 
Rivellia, Robineau-Desvoidy, Essai sur les Myodaires, p. 729 (18380). 
This genus is represented in the Mexican collections by eight species. The wings 
have a blackish pattern, consisting of four more or less complete cross-bands—the first 
often connected with the blackish basal marking, the second including the small cross- 
vein, the third bordering the posterior cross-vein, and the fourth forming a border at 
the tip. The greater or less extension of these bands, and their general contiguity, 
afford good specific characters. 
1. Legs yellowish-rufous. 2. 6. ee ee ee ee 
Legs black (in R. pilosula and R. longicornis piceous or dark rufous) . 4. 
2. Base of the wings hyaline; the cross-bands very narrow . . . . . occulta, v.d. W. 
Base of the wings blackish . . . . . . . 3 
3. The first cross-band united with the ‘blackish pattern of the base, 
inferiorly not reaching the fifth vem . . toe ee ee micans, Liaw. 
The first cross-band separated from the blackish pattern of the base, 
inferiorly reaching to beyond the fifth vem . . . . . . . . « submetallica,v. d. W. 
* Incorrectly termed H. metallica by Low. 
