49 
PLATES XIII. AND XIV. 
SYNOPSIS OF THE DIPTEROUS FAMILY MIDASIDJE, WITH DESCRIPTIONS 
OF NUMEROUS NEW SPECIES. 
This family, having for its type the genus Midas*, comprises some 
of the most gigantic species of Dipterous insects, remarkable for the 
great elongation of the antennae, the (lark or coloured wings in 
many of the species, and occasionally the metallic appearance of the 
body ; in all which respects we find a singular analogy to the gigantic 
Sphegidee belonging to the tribe of fossorial Hymenoptera, which 
inhabit the same regions as are frequented by the Midasidse. 
The antennae, which in some species are nearly as long as the 
thorax, appear in reality to be formed of only four joints, the third 
being occasionally bi- or tri-annulate, and the fourth sometimes 
biannulate; so that, as in M. lusitanicus (Meig. vol. 6, t. 66, f. 2), 
the antennae appear seven-jointed. If the minute, and, indeed, 
often obsolete, style at the extremity of the antennae be taken into 
consideration, we have a five-jointed antenna analogous to that of 
Dasypogon, &c. 
Much confusion exists in the works of Dipterologists as to the 
structure of the mouth, and Macquart acknowledges his inability to 
determine its structure, by observing which, lie had hoped to have 
determined the real situation of this anomalous group. I have been 
more fortunate, and having extracted the different parts, have repre¬ 
sented them in pi. 13, fig. a — e. The proboscis is terminated by 
two large lips, and the haustellum consists of a labrum, long, slender, 
channelled beneath, and notched at the tip (d), inclosing beneath a 
short acute seta or lingua (e) ; a little in advance of the base of the 
labrum arises a pair of slender curved setre, which Fabricius 
evidently regarded as palpi, but which I consider as the analogues 
of the maxilke of the Asilidse, and as destitute of palpi. Latreille 
indeed adds, t; Palpi brevissimi f (Gen. Cr. 4. 294) ; but I have seen 
nothing of them. If w r e regard them as palpi, we have a mouth 
analogous to that of the Muscidee, whilst it is evident from the 
remainder of the characters of the group that the Midasidse really 
belong to the Tanystomatous division of the order. 
* I have adopted the orthography of the generic name Midas, given by "Wiedemann (in his 
monograph in the Nova Acta, vol. xv. pt. 2), in correction of the Fabrician name Mydas, the 
term being evidently proposed in allusion to the long-eared King Midas. 
E 
