102 THE ENTOMOLOGIST. 
Macrocerine, Ceratoplatine, Sciophiline, and Mycetophi- 
line. Mycetobia (sub-fam. 2) differs especially from Diado- 
cidia (sub-fam. 1) in the much greater Jength of the subcostal, 
and in the nearer approach of the radial to the tip of the 
wing. Ditomyia (sub-fam. 2) differs from Mycetobia in the 
incomplete and very short subcostal, in the forked cubital, 
and i jn the much longer fork of the prebrachial. In Platyura 
(sub'-fam. 5) the subcostal is complete but short, the radial is 
much shorter than that of the Ditomyia, and the fore fork of 
the cubital is very short. In Bolitophila (sub-fam. 3) the 
subcostal is elongated, the fore fork of the cubital is as short 
as that of Platyura, but joins the radial near the tip of the 
latter; the first pobrachial is much longer than in any of the 
preceding genera. In Macrocera (sub-fam. 4) the subcostal 
and the radial are shorter, and the very short fore fork of the 
cubital is beyond the tip of the radial; the curve of the 
cubital also distinguishes this from all the preceding genera. 
In Sciophila (sub-fam. 6) a greater change occurs in the 
structure of the bones; the cubital has two short approximate 
directly transverse forks, which join the radial. In Tetrago- 
neura, belonging to the same sub-family, the structure is still 
more altered; the subcostal is incomplete, and very short; 
the radial and the cubital are gathered closer to the costa, 
and the two forks of the radial are shorter and more approxi- 
mate than in Sciophila, and the two branches of the 
pobrachial are much nearer to the tip of the wing. In 
Gnorista and in Mycetophila (sub-fam. 7) the cubital is 
simple, and the arrangement is much like that of Diadocidia 
and of Mycetobia, excepting the peculiar curved radial of the 
latter. In the Mycetophila, here figured, there is no sub- 
costal, and the prebrachial does not form two branches. In 
Sciara (div. Sciarimi) the resemblance to Tetragoneura is 
apparent; the radial and the cubital are curved near the 
costa; the other veins are slight or secondary, and the 
prebrachial does not form two branches. There is a transi- 
tion from Sciara to Cecidomyia when the veins are very few; 
but these notes are limited to the figures which they accom- 
pany. The flight of all the preceding genera is feeble, short, 
and flitting; that of Bibio (fam. Bibionide) is hovering, and 
of long continuance, and there is another plan in the con- 
struction of the wing-bones. . 
Francis WALKER. 
