THE ENTOMOLOGIST. 39 



praBbrachial, or the discal, and the ])obrachial areolets, 

 scarcely admitting of any finllicr classilicalion, arc 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 il affords, has received a peculiar 

 name (the subapical arcolet) ; 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 

 praebrachial vein, of which in most of these cases it appears 

 as the continuation. This subapical vein is often (Cyrloncura, 

 Alophora, Hyalomyia, Conops, Pangonia, and many Syr- 

 phidac, &c.) curved, so as to meet the cubital vein and close 

 the subapical areolet before the margin (many Muscidae, 

 Tachinini, Syrphidas), 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 Asilidae, Cyrlus, &c.), 

 the last but one of the externo-medial veins running obliquely 

 or transversely to meet the last of thera. In Nemeslrina, 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 praebrachial, discal, ]iobrachial 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 ap})ly 

 tlie nomenclature to the Diptcra Brachycera. Among these, 

 having followed out the gradual simplification of the system 



