38 THE ENTOMOLOGIST. 
“The cubital areolet lies between the radial and cubital 
veins; if the latter is branched a second cubital areolet is 
enclosed between its branches, as is ordinary with many 
families of Diptera, e.g. Tabanide. In this case, parti- 
cularly, the cubital and radial veins are not uncommonly 
joined by a transverse vein, forming a third cubital areolet. 
When this is the case the direction of the veins may be so 
modified as to make it doubtful whether the radial or cubital 
vein be the one that is branched; but analogy to allied 
genera will generally give a clue, even where the direction of 
the veins is so far changed as to give the contrary appearance, 
as in some of the Asilide. Rarely the cubital vein also 
returns to the subcostal, so that the cubital areolets do not 
extend to the margin; this is the case in Hirmoneura and 
in Midas. 
“‘ Before the prebrachial vein lies the prebrachial areolet, 
bounded in front by portions of the (subcostal) radial and 
cubital veins, or some of them, and at the tip by the 
prebrachial transverse vein. Between the prebrachial and 
pobrachial veins is the pobrachial areolet, usually bounded 
at the tip by a more or less evidently oblique or transverse 
vein (the pobrachial transverse vein), often in connection 
with a twist or branching of the longitudinal veins. Between 
the pobrachial and anal veins lies the anal areolet, which.is 
open to the margin when the subanal vein runs on as a con- 
tinuation of the pobrachial, as in the Tipulidez generally, and 
in some other cases, but becomes closed when the subanal 
vein runs to join the anal; either obliquely, as in Syrphide, 
Conopide, Stratiomyde, Asilide, and the neighbouring 
families in general; or transversely, as in most Muscide, 
many Empide, and the Dolichopide. These three areolets: 
(the prebrachial, pobrachial, anal), sometimes jointly called 
the ternate areolets, can in most cases be determined from 
the manner in which the conjugate axis divides into the 
three veins,—prebrachial, pobrachial, and anal; and their 
determination is of prime importance for the determination of 
the others. A very characteristic areolet, also, when it is pre- 
sent, is the discal, which (generally speaking) lies beyond the 
prebrachial and pobrachial, commencing in the angle between 
the tips of these two. 
“The veins which run to the margin of the wing from the 
