118 
Psyche 
[December 
The whole insect is remarkably brilliant blue-green, 
metallic, vitreous, covered everywhere with deep punctures 
or pits, and on the abdomen small creases, in shape and 
appearance presenting an astonishing resemblance to a 
Chrysidid wasp, altogether the most remarkable case of 
mimicry I have ever beheld. 
Tityusia new genus 
Large flies, the males narrowly holoptic, the upper facets 
slightly enlarged, the antennal prominence well developed, 
the antennae have the third joint suborbicular and the arista 
bare. First and second joints short. Face with a very low 
median tubercle, not greatly produced either anteriorly or 
ventrally. Post-occiput flared posteriorly backwards about 
central opening, and long pilose. 
Thorax and scutellum normal, with very dense pile of 
median length, the rim of the latter simple. Metanotum 
with a horizontal depression or crease. Abdomen broadly 
oval, broad basally, tapering posteriorly, yellow maculate 
somewhat similar to species of Heloyhilus and Mesembrius. 
Hind femora moderately thickened, but unarmed poste- 
riorly with either spines or setae. The black basal patch 
of setulae present. Anterior femora greatly thickened, 
especially apically and from the apical third of the posterior 
margin a very thick brush of dense dark pile is sent back- 
ward, much as if the hairs of a brush had been wetted. 
Fore tibise still more extraordinary, enormously thickened, 
grooved, twisted and distorted, the median and lateral edges 
bare, dense fringes of dark pile extremely long, extremely 
matted, directed backward. Fore tarsi extravagantly flat- 
tened on the dorso-ventral axis, the lateral edges of the 
second, third and fourth segments prolonged into narrow 
down curving lobes. Median pair of legs simple, except that 
their tarsi are flattened somewhat. Posterior tibiae slightly 
flattened. Posterior basitarsi nearly as long as post tibiae, 
on its distal end bearing an enormous brush of dark matted 
hair, its basal end equipped with the characteristic glob- 
uliferous hairs of Mesembrius. Marginal cell of wings 
narrowly open. Halteres long stalked, the knob with a deep 
cup shaped depression. This may be due to drying. 
Genotype : Tityusia regulus new species. 
