THE ENTOMOLOGIST. 39 
prebrachial, or the discal, and the pobrachial areolets, 
scarcely admitting of any further classification, are compre- 
hended under the general name of externo-medial veins, and 
the areolets adjacent to them are called externo-medial, and 
discriminated when necessary by their ordinal number, com- 
mencing with that nearest the tip of the wing. This one only, 
on account of the characters it affords, has received a peculiar 
name (the subapical areolet) ; it lies immediately behind the 
cubital areolet, and is bounded behind by a vein (the first of 
the externo- medial veins), which is also, when it has to be 
noticed, called subapical vein, or subapical portion of the 
prebrachial vein, of which in most of these cases it appears 
as the continuation. This subapical vein is often (Cyrtoneura, 
Alophora, Hyalomyia, Conops, Pangonia, and many Syr- 
phide, &c.) curved, so as to meet the cubital vein and close 
the subapical areolet before the margin (many Muscide, 
Tachinini, Syrphidez), or it is forked, and the anterior branch 
runs obliquely towards or to the cubital vein, and becomes to 
all intents a transverse vein (the subapical transverse), closing 
the subapical areolet as before mentioned. 
*¢ Sometimes another of the externo-medial areolets becomes 
closed before the margin (as in‘many Asilidz, Cyrtus, &c.), 
the last but one of the externo-medial veins running obliquely 
or transversely to meet the last of them. In Nemestrina, and 
a few allied forms, the areolets towards the posterior margin 
and tip of the wing become so subdivided by supernumerary 
veins that it is only by comparison with simpler forms that 
we can trace the limits of the cubital area and the two 
branches of the cubital vein, the externo-medial veins being 
too complicated for any available denominations. But here, 
also, the prebrachial, discal, pobrachial and anal areolets 
being distinct, the boundaries of the externo-medial portion 
of the wing are still defined. The portion of the wing which 
lies behind the anal vein and beyond the axillary lobe, or 
sinus, is divided by the subaxillary vein into two open 
areolets, the axillary before and the subaxillary behind that 
vein, or if the vein be wanting the whole space is comprised 
under the former of these. 
“In general, it is easiest to trace out the analogy and apply 
the nomenclature to the Diptera Brachycera. Among these, 
having followed out the gradual simplification of the system 
