50 
SYNOPSIS OF THE DIPTEROUS 
We find an almost identical arrangement of the veins of the 
wings exhibited by this group and by Nemestrina amongst the 
Anthracidse *. 
Olivier, evidently from personal observation of the species which 
lie found in Egypt, thus describes their habits, which resemble 
those of Asilus and Dasypogon. “ Ils vivent de rapine et font une 
guerre continuelle aux autres insectes, qulls attrapent en volant, 
et dont ils retirent tous les sues au moyen de leur trompe. On les 
voit attaquer les Hymenopteres les plus fortes et les niieux armes, 
et les emporter entre leurs longues pattes, sans que Taiguillon de 
ceux-ci puisse les atteindre. Leurs larves nous sont inconnues. 1 ’ 
To this account I am able to add, from information given to me 
by Mr. MacLeay, that the larvae of M. tricolor (which he observed 
in Cuba) are parasitic upon the larvae of the giant Prionidae. 
Wiedemann described all the species known to him under the 
genus Midas; but Latreille separated from them a sub-genus, 
having the proboscis long and porrected, named Cephalocera; and 
Macquart added a third, Rhopalia, differing only in the alteration 
in the veining of the wings and the thickened mass at the extremity 
of the antennae. If, however, this be admitted, it will become 
necessary to form another for my M. auripennis, which would, I 
consider, be unnatural. Six years ago I described another genus 
from Australia, which I refer to this family, on account of the 
similarity in the veining of its wings, although it is perhaps doubtful 
whether it is not more nearly related to the Nemestrinides. 
Genus MIDAS, TVied . (Mydas, Fabr.) 
Species I.— M. heros , Perty. (Del. Anim. Art. Braz. t. 36, f. 11.) Ater, antennis 
ferrugineis, abdominis segmento lmo sulphureo-hirto, alis antice testaceis costa et venis 
fusco-nigris. Long. lin. .26. Expans. alar. lin. 42. Brasilia. 
Species II.— J\I. giganteus , Thunberg. (Sw. Trans. 1318, p. 246, Wied. Mon. Mid. 
tab. 52, fig. 1, £ J.) Ater, tborace vittis dilutioribus; abdomine ckalytoco, $ 
vix crerulescente ; alis in £ cothurnatis vcl fuscanis, in £ nigris ; margine iuteruo 
apieeque fuscano-flavidis. Long. corp. lin. 15—18 20 Brasilia. 
Obs. 1.— M. ccerulescevs , Oliv. Enc. Meth. 8, p. 81, is regarded by 
Wiedemann as identical with the male of this species. Olivier, 
however, says, “ L’abdomenest d’un bleu tr^s-btillant,’ 1 which will 
scarcely agree with it. The Rev. F. W. Hope possesses a variety 
of the male with the abdomen black, and the front margin of the 
wings pale brown, scarcely darker than the hind margin. 
Species III.— M. dives, W r estw. n. sp. PI. 13, fig. 1. Niger, tborace vittis cinerascentibus, 
abdominis segmento lmo aureo piloso, 2do aureo-sericauti, reliquis late purpureo- 
caeruleis ; antennis, articulis 2us basalibus exceptis, alisque fulvis, harum basi obscuriori 
margineque postico translucente, pedibus longis £ . Long. corp. lin. 18. Exp. alar, 
unc. 3J. In Mus. D. Hope. 
* Latreille refers to Pangonia, but evidently in mistake for Nemestrina (R. A. 5. 480). 
