362 INSECTA, 
its general divisions as given by M. de Blainville in his report to the 
Academy, we are unable to profit by it. Independently of this, we 
should have been compelled to pass beyond our prescribed limits, and 
perhaps have terrified the young naturalist, by an exposition of the 
multitude of new genera he has established in this tribe, several of 
which, even in the opinion of the reporter, appear to differ but little 
from each other. We even think that the work of M. Meigen, with 
the exception of the revision of the two genera above mentioned, is 
amply sufficient for the actual wants of the science. 
Dr. Desvoidy has employed but very few characters of his own in 
designating these groups. ‘There are even some which he might 
have used to advantage, such as the disposition of the nervures of the 
wings, which he has neglected, at least in the work presented to the 
Academy. His first family, that of the Ca/ypterees, is identical with 
the one I call Creophiles in my “ Familles Naturelles du Régne 
Animal,” and which, besides, was already established in my preceding 
works. According to the analysis of his Memoir given by M. de 
Blainville, it is evident that the characters of the nine other families 
of the Myodaires are generally founded on the mere diversity of 
their mode of habitation, their colours, and on some other vague 
considerations. 
We will endeavour to arrange the genera of Messrs. Wiedemann 
and Fallen which we have been able to study, in our former method, 
but with some modifications which the observations of these cele- 
brated naturalists, and others of my own, render necessary. 
This tribe will comprise the genus 
Musca, Lin. 
Antenne inserted near the front, palpi placed on the proboscis, and 
retiring with it into the oral cavity, and tranverse nervures in the 
wings, characterize a first section of the winged Muscides, which will 
include eight principal groups or sub-tribes. 
Those of our first division, Creopnitm, have large alule, which 
almost completely cover the halteres. ‘The wings are almost always 
distant, with the two terminal and exterior cells of the posterior edge * 
closed by a transverse nervure, 
Of the species which always present these characters, we will dis- 
* The most external one is situated under a narrow, elongated cell, closed by the 
posterior margin, which may be considered as a sort of cubital cell. In the follow- 
ing divisions, this exterior cell is not closed by a transverse nervure. The second, or 
that which adjoins the inner side of the preceding one, is also closed in the last of 
the Muscides; but it is no longer terminal, and frequently it is even shorter; the 
longitudinal nervures which form the sides are prolonged to the posterior margin, 
thereby forming another cell, which becomes terminal and incomplete. In the Creo- 
philee the two nervures are not (or but very slightly) prolonged beyond the closed 
cell. 
