RHOMBOTHYRIA.—PSEUDOMORINIA. 259 
RHOMBOTHYRIA, gen. nov.* 
Head hemispherical; front not prominent, convex; frontal bristles stout; face indistinctly carinated ; eyes 
bare, descending to near the lower part of the head ; vibrissal swellings parallel; vibrisse inserted near 
the oral margin, which is not prominent. Antenne inserted in a line with the centre of the eyes; third 
joint longer than the second, reaching to half the face; arista short-plumose. Proboscis short, with well- 
developed terminal lips; palpi small, cylindrical. Thorax quadrangular; scutellum with long macro- 
chete at the hind margin. Abdomen subcylindrical, with stout, though not very long, discal and marginal 
macrochetz. Legs slender, with scattered weak bristles ; foot-claws and pulvilli short (in both sexes ?). 
Wings longer than the abdomen ; costal margin slightly curved, and with a row of very short bristles over 
its whole length ; curvature of the fourth vein rounded; apical cell rhomboidal, opened nearly in the 
wing’s tip; posterior cross-vein beyond the middle between the small cross-vein and the curvature of the 
fourth vein. 
1. Rhombothyria flavicosta, sp. n. (3%). (Tab. VI. figg. 13; 18a, head.) 
Thorax and scutellum cinereous, the thorax with black stripes ; abdomen black, the second and third segments 
with grey front borders ; legs black, the base of the femora and the knees rufous; antenne rufous, brown 
at the tip. 4 
Length 9°5 millim. 
Head yellowish, with grey reflections ; front slightly narrowed behind; frontal band black; posterior orbits 
whitish-grey, with a row of short black bristles. Antenne rufous; third joint twice as long as the 
second, infuscated towards the tip; arista black, thickened in its proximal half. Proboscis black, the 
terminal lips and the palpi yellow. Thorax cinereous; thoracic dorsum with several black stripes, which 
behind the transverse suture become diffused into a more general black coloration ; scutellum cinereous, 
with the base black. The grey front borders of the second and third abdominal segments are interrupted 
in the middle by a black dorsal stripe; the discal macrochexte are inserted close to the anterior margins 
of the segments. Legs black; the end of the coxe, the base of the femora, and the knees rufous ; foot- 
claws and pulvilli short. Tegule yellowish-grey. Wings greyish-hyaline, along the costa with a yellow 
tint ; second and third veins arcuate; small cross-vein under the end of the first vein and nearly on the 
middle of the discal cell ; apical and posterior cross-veins straight. 
Hab. Mexico, Venta de Zopilote in Guerrero 2800 feet (H. H. Smith). 
Six specimens, which I suppose to be males, owing to the conformation of the 
front, 
PSEUDOMORINIA, gen. nov. 
Head hemispherical; front not prominent, narrowed behind in the male; face indistinctly carinated ; cheeks 
broad, their lower portion scarcely equalling half the longitudinal diameter of the eyes; vibrissal swellings 
parallel; vibrissee inserted near the oral margin, which is not prominent. Eyes bare. Antenne inserted 
on or a little below a line drawn through the centre of the eyes; third joint longer than the second ; 
arista short-plumose. Proboscis short, with the terminal lips distinct and turned backwards; palpi 
slender, cylindrical, Abdomen elliptical, with discal and marginal macrochete. Legs with scattered 
bristles; foot-claws and pulvilli elongate in the male. Wings longer than the abdomen, marked with 
black and yellow ; apical cell opened just before the wing’s tip ; curvature of the fourth vein with a blunt 
angle ; posterior cross-vein nearly in the middle between the small cross-vein and the curvature of the 
fourth vein. 
* SiuBos (rhombus) ; Oupis (cell). 
212 
