294 INSECTA. 
Here the abdomen is always convex, with very distinct, and more 
or less triangular annuli. 
In these, the seta of the antennz, of which the second joint is 
much elongated, is geniculate, and forms an angle near its middle, 
at the junction of that joint with the following one, or the last divi- 
sion of the seta. 
Gonta, Meig.(1) 
In those, as in the other Creophilz, the seta of the antenne is not 
geniculate near its middle. 
MitrocramMa, Meig. 
Where the third joint of the antenne is much longer than the 
preceding one(2). 
Trrxa, Meig. 
Where its length but little exceeds that of the second(3). 
There the abdomen is sometimes strongly inflated, and, as if vesi- 
cular, with the divisions of the annuli but slightly marked; some- 
times it is much flattened. The wings in the last case are very dis- 
tant, and frequently somewhat arcuated exteriorly. 
GymnosomiA, Meig.— Tachina, Fab. 
Where the abdomen is inflated, as if vesicular or ovoid, with the 
separation of the annuli rather indistinct; the antenne are as long as 
the face of the head, the second and third joints of almost equal 
length, and the latter linear(4). 
CisToGASTER, Lat. 
Where the form of the abdomen is the same; but the antenne are 
(1) Meigen. 
(2) Idem. 
(3) Idem. 
(4) Idem. 
