364 



THE WINGS OF HYMENOPTERA 



Ro, which is lacking in this genus, is added. This vein is well-preserved in 

 Macroxyela (Fig. 392) ; but in Macroxyela vein Cuo is lost; the position of 

 the lost forking of the cubitus is indicated, however, by a bend in this vein. 

 In the wings of these sawfiies, the anal furrow and the median furrow 

 are both well-marked, and are in the typical positions; that is, the anal 



Fig. 382. — The veins of a typical hymenopterous wing (From C. & N.). 



furrow is immediately in front of the first anal vein and the median farrow 

 in front of the media. The furrows are represented by dotted lines in 

 Figures 382 and 383. 



In the anal area the three typical veins are preserved ; but they coalesce 

 to a considerable extent, both at the base and near the margin of the wing. 



In the basal part of the prenal area, the stems of the principal veins are 

 as follows: the costa coincides with the costal margin of the wing and 

 extends from the base of the wing to the stigma (Fig. 382,0);* the subcosta 



Fig. 383. — The cells of a typical hymenopterous wing (From C. & N.). 



(Fig. 382, Sc) is well-preserved and is forked; back of the subcosta is a 

 strong stem formed by the coalescence of the other three veins of the preanal 



*It is impossible to state whether the costa extends beyond the beginning of the 

 stigma or not. Both MacGillivray and Bradley believe that it ends at or shortly 

 before the beginning of the stigma. This conclusion is based on the fact that, while 

 costa in all insect wings, when present, lines the margin of the wing, in the Hymenoptera 

 there is frequently a strip of free membrane of varying width extending from the nodal 

 furrow to the apex of the wing. This strip is quite wide in the wings of the female of 

 Tiphia, for example; and widens into the appendiculate cell in some wings. 



