DIPTERA. 3738 
and usually projecting and distant; the palette, never much longer 
than it is wide, is sometimes almost ovoid, or bordering on an oval, 
and sometimes nearly globular. 
Some, in which the seta of the antenne is usually pilose, have 
the narrow and elongated body of the preceding ones ; the abdomen of 
several also terminates in a point or stilet. 
Of these Muscides, some have a naked face, and the palette of their 
antenne more or less ovoid or oval. 
Such are the two following subgenera : 
Lissa, Mevq., 
Where the top of the head presents a prominence, and the almost 
linear abdomen is not terminated by an articulated stilet*. 
Psttomy1A, Lat.—Psina, Meziq., 
Where the body is proportionally less elongated and cylindrical 
_ and the abdomen of the females terminates in an articulated stilet f. 
To this subgenus may be united the Geomyze@ of Fallen }. 
The Tetanura and Tanypezaof M. Meigen appear to approach the 
preceding subgenera. In both, however, the legs seem to be pro- 
portionally longer and more slender. The abdomen of the Tetanure 
is obtuse and thickened at the end. 
The first exterior nervure of the wings is simple, and does not pro- 
duce a stigmatiform cell; the exterior terminal cells are distant §. 
The abdomen of the female Tanypeza is terminated by a point or 
stilet. The first terminal cell, that which comes after the cubital, 
is almost closed at the end, or forms a narrow, elongated, and trun- 
cated triangle. I suspect that this subgenus belongs to the division of 
the Dolichopoda\|. 
In others, the sides of the face are furnished with hairs; the first 
joint of their antennz is much more slender than the following ones, 
almost cylindrical, and somewhat thickened at the end ; the two fol- 
lowing ones form a small rounded club. 
LoncnorteEra., Metg.—Drrsa, Fall., 
Where the ocelli are placed on an eminence. The wings are long 
and exhibit no transverse nervure beyond their base ; the third longi- 
tudinal, nervure, from the exterior margin, is bifurcated. This sub- 
genus is far removed from the Dolichopoda, near which Meigen has 
placed it. 
The body of the other Scatomyzides is thicker and less oblong, ap- 
proaching more to the form of that of the common Fly. 
One single subgenus, as the 
Heveomyza, Faill., 
Presents mustachios **, 
* Meigen. 
t+ See Meigen. I have changed the name of Psila, because it too nearly re- 
sembles that already given to a genus of the Hemiptera. 
t Fall., Dipt. 
§ Meigen. 
|| Idem. For the genus of Tetanops, which in some respects seems to belong to this 
division, see that of the Carpophila. 
¥ See Meigen. 
** Fall., Dipt.: the Mouche des latrines (Afusca serrata, L.) of De Geer, which is 
