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. Tabanidse. 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 Asilidoe. 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 liirmoneura and 

 in Midas. 



" Before the praebrachial vein lies the prsebrachial areolet, 

 bounded in front by portions of the (subcostal) radial and 

 cubital veins, or some of them, and at the tip by the 

 prajbrachial transverse vein. Between the praebrachial 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 Tipulidse generally, and 

 in some other cases, but becomes closed when the subanal 

 vein runs to join the anal ; either obliquely, as in Syrphidai, 

 Conopida3, ^tratiomydae, Asilidae, and the neighbouring 

 families in general ; or transversely, as in most Muscida?, 

 many Erapida), and the Dolichopidae. These three areolets 

 (the praebrachial, 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, — praebrachial, 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 

 praebrachial and pobrachial, commencing in the angle between 

 the tips of these two. 



"The veins which run to the margin of the wing from the 



