DIPTERA. 333 
Of those in which the antennz are much shorter, the 
Xxstomyza, Wied.. 
Approximates to Toxophora in the lengty of the first! joint of those 
organs, which is considerably greater than that of the others; it 1s 
almost fusiform, as well as the third or last*. 
Apatomyza, Wied., 
Is another subgenus in which the first joint of the antenne is also 
very long; but here that joint is cylindrical ft. 
In the following subgenera of the same division, or of those whose 
proboscis is long and setaceous, or filiform, the last is the longest. 
Sometimes the two first joints of the antenne are short and almost 
of equal length. 
Lasius, Wied., 
Where the head, in one of the sexes, is almost entirely occupied by 
the eyes, and the last joint of the antennz is very long, almost linear, 
compressed, and without any apparent terminal seta. The abdomen 
is voluminous. The labrum is large, gibbous at base, and truncated 
at the end. 
In one specimen, for which I am indebted to the kindness of M. 
de Lacordaire, the proboscis extends along the under part of the body 
and projects beyond its posterior extremity. This character, with 
some others, would seem to indicate that this subgenus naturally be- 
longs to the tribe of the Vesicularia, and comes near Panops }. 
Usia, Lait—Vorvucea, Fab., 
Where the last joint of the antenne is ovoido-conical, cbtuse or 
truncated at the end, aud terminated by a stilet. The palpi are not 
apparent. 
The species are peculiar to the southern countries of Europe 
and to Africa §. 
Puruiria, Meig. 
Similar to Usia in the antennz, but the palpi are distinct ||. 
Sometimes the second joint is evidently shorter than the first; the 
last is long, generally almost cylindrical, and terminated in a point, 
as in 
Bompy ius, proper, 
Where the palpi are very apparent. 
These Insects are densely covered with a woolly down, which co- 
lours it. The most common species in the environs of Paris is the 
BY! mayor, i. ; Be biehon, De Geer, Insect:, VI, xv, 10,11. 
From four to five lines in length, and entirely covered with yel- 
lowish-grey hairs; proboscis long and black; external half of 
the wings blackish, the remainder diaphanous ; legs fulvous. 
gr Wicdapeipts, sot, Lod, Eaml. 
+ Id., Ibid., If. I have never seen a species of this genus. 
t Wied., Anal, Entom., I, 3. 
§ Lat., Gener. Crust. et Iasect., 1V, 314. See also Fab. and Meig. 
|| The same works. 
