DIPTERA. 375 
as the first, but does not appear to me to be sufficiently removed from 
the Oscini*. 
The fifth division, that of the Dortcaocera, and which embraces 
the genus called Tetanocera by M. Duméril, closely approaches the 
fourth; but the length of the second joint of the antennz which is 
here equal to that of the third, or the palette, and most frequently 
surpasses it, serves to distinguish them. These organs, always dis- 
tant and projecting, are, with but few exceptions, as long as the 
head or longer, and terminated ina point. The superior plane of the 
head forms an obtuse triangle, or one truncated at the apex. The 
face is smooth or but slightly silky. 
In some the antenne are shorter than the head. 
Orires, Lat., 
Where the seta of the antennz is simple and the inferior extremity 
of the head, or its oral portion, does not project f. 
Eutuycera, Lat., 
Where the second joint of the antenne is larger than the following 
one, almost square, and the latter is triangular and pointed, with a 
plumous seta. The inferior extremity of the head projects in the 
manner of a truncated snout f. 
The antennz of the others are manifestly as long as the head, or 
longer. 
Srerepon, Lat.—Baccua, Fab., 
Where the antennz are considerably longer than the head, with the 
second joint much longer than the last and cylindrical ; the latter forms 
an elongated, pointed triangle, furnished with simple setz §. 
Teranocera, Dum., Lat.—Scaroruaca, Fab., 
Where the antenne are as long as the head, or a little longer, with 
their second joint compressed, forming a long and narrow square, as 
long as the third, or only a little longer; the third joint is similar 
confounded with the preceding one. In Oscinis or Piophila and Chlorops, the sum- 
mit of the head, as we have already stated, presents posteriorly a triangular space 
sometimes even slightly prominent, and usually brown and glossy, on which the ocelli 
are situated. The antenne are always distant, and the seta is simple. The body alone 
is pubescent. Thelegs are proportionally more robust than those of the Heleomyz@, 
and it is evident that these Insects approach the Tetanocera. Messrs. Fallen and 
Meigen have not sufficiently compared the characters of the genera they have esta- 
blished, nor endeavoured to approximate them in a natural series, which makes it a 
difficult matter to discern the difference between several of them. I have frequently 
been embarrassed with genera, from which I could have been relieved by the work 
of the latter, but it is not yet published. 
* See the Nouv. Dict. d’Hist. Nat. 2d edit., article Oscine, divis. II, and Lat., 
Gener. Crust. et Insect., [V., 361; Oscinis lineata, and the following species. See 
also with respect to Piophila, Fallen, Meigen, aud Wiedemann—Analect. Entom. 
+ Lat., Hist. Nat. des Crust. et des Insect.; the second edition of the Nouv. 
Dict. d’Hist. Nat. article Oscine, divis. 1; and Lat., Gener. Crust. et Insect., IV, 
351; to this subgenus I also refer the Oscinis umbraculata, Fab. 
t Scatophaga cherophylli, Fab. ; and some species of Tetanocera. 
§ Lat., Gener. Crust. et Insect., IV, 349. 
