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DIPTERA. 355 
Merovon, Meig., Fab.—Muvesia, Eristauis, Lat—Syreuvus, Fab., 
Where the abdomen is triangular or conical, without being narrowed 
at base, and where the external cell of the posterior edge of the 
wings is deeply emarginated exteriorly. 
M. narcisst; Eristalis narcisst, Fab.; Reaum., Insect. IV, 
xxx. Obscure-bronze, but covered with fulvous down; legs 
black; inner side of the posterior legs tuberculous. 
The larva feeds on the interior of the bulb of the Narcissus *. 
Ascra, Meq., Meiq., 
Where the abdomen is narrowed at base and clavate. The two first 
closed cells of the posterior edge of the wings terminate in an angle; 
the exterior side of the first is straight ft. 
Sometimes the palette of the antennz is short, or moderately elon- 
gated, and either almost orbicular or nearly ovoid. 
Here, as in the last subgenus, the abdomen is narrowed at base and 
clavate. 
Spueeina, Meig., 
Where the palette of the antenne is orbicular. The posterior thighs 
are clavate and spinous underneath f. 
There, the abdomen is either triangular or conical, or almost cy- 
lindrical. 
In some, the wings hardly extend beyond the abdomen, which is 
frequently narrow and elongated. 
We will separate those whose posterior thighs are strongly in- 
flated, with the inner side armed with small spines. The closed cells 
of the posterior border of the wings are sinuous posteriorly. 
Eumerus, Meiq., 
To which we unite his Zylote, where the abdomen is merely nar- 
rower and almost linear, and which we formerly placed among the 
Milesiz. Such is the 
E. pipiens; Musca pipiens, L.; Panz.; Faun. Insect. Germ. 
XXXII, 20. About four lines in length; black; each side of 
the abdomen spotted with white. The humming it produces 
while on the wing is mingled with a sharp sound resembling 
the note of a young chicken §. 
In the two following subgenera, the posterior thighs sometimes 
differ but little from those of the preceding ones, and are sometimes 
thicker, but unidentated at most. 
Mivesia, Lat., Fab., Meig.—Trerivia, Meiq., 
Where the two posterior legs are abruptly larger than the others, 
with thick and unidentated thighs in several. The body is elon- 
* See Meigen. 
+ Idem. 
~ Idem. 
§ See Meigen, genera Eumerus and Xylota. 
