DIPTERA. 261 
turned up or withdrawn, cylindrical or clavate, and resembles those 
of the Notocanthi. The legs are short and spineless, and the pos- 
terior tarsi frequently broad and flattened. 
These Diptera are very small. M. Macquart has furnished us 
with various interesting observations on the habits of several species. 
Some have a seta on the last joint of the antenne. 
Those, in which that seta is terminal, whose eyes are contiguous 
_in the males, and the three first joints of whose posterior tarsi, or 
the first at least, are wide and flattened, form the subgenera 
Cattomyia, Meig. 
Where the first joint alone of the posterior tarsi is dilated, but is 
as long as all the others taken together. 
PiatypPEza, Meig. 
Where the four first joints of the posterior tarsi are dilated. 
__. Those, in which the seta is inserted on the back of that joint, near 
its junction with the preceding one, whose tarsi are not dilated, and 
whose eyes are separated in both sexes, compose the genus 
Piruncutus, Lat.—Cephailops, Fallen. 
Where the head is almost globular. 
The others have no seta on the last joint of the antenne. It is 
narrower and longer than in the preceding Insects. 
Scrnopinus, Lat. Meig.—Musca, Lin. 
To which belongs the following species. 
S. fenestralis; Musca fenestralis, L.; Schell., Dipt. XP. 
the female; 2, the male. Head and thorax obscure bronze; ab- 
domen black, transversely striate, streaked with white in the 
male; legs fulvous; tarsi obscure. Very common on the glass 
in windows(1). 
ig 
(1) For all these subgenera, see the authors already quoted. 
