50 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 39. 



any vein, taxinomists, especially in the Hymenoptera, will probably 

 continue the use of more convenient, though less significant, indi- 

 vidual names for the veins. An unfortunate thing in this connection 

 is that systematists in different orders have, in many cases, used the 

 same names for entirely different veins. 



Axillaries (Ax). — The little sclerites at the base of the wing wliich 

 hinge the latter to the notum and pleurum. Many individual names 

 have been given to these sclerites by different students, but the 

 writer has selected the general term of axillaries proposed by Strauss- 

 Diirckheim (1828) for those of the hind wing of Melolontha, distin- 

 guishing the individual plates as the Jirst, second, third, and fourth. 

 The fourth is usually absent except in Orthoptera and Hymenoptera, 

 but the other three are of almost universal occurrence in all the winged 

 orders except the mayflies and dragonflies. 



AxC 



Fig. 9. — Bask of feont wing of Asynarchus punctitissimus (caddicefly): lA, first anal vein; 

 lAx, ZAx, SAx, FIRST, second, and third axillaries; Ax C, axillary cord; C, costa; Cu, cubitus; M, 

 media; R, radius; Sc, subcosta; Tg, tegula. 



The axillaries, their relations to the back and to the base of the 

 wing, are shown diagrammatically by figure 8. The first {lAx) nearly 

 always has a curved anterior neck which rests u})on the anterior notal 

 wing process {ANP), while its body is hinged to the edge of the notum 

 back of the latter. Its anterior end is associated with the base of the 

 subcosta {8c). The second {2 Ax) is the pivotal sclerite of the wing 

 base, since it rests and turns upon the wing process of the pleurum. 

 Its anterior end is associated with the base of the radius {U). The 

 third axillary {3 Ax) is associated with the bases of the anal veins, 

 except with the first {lA) when this vein is separated from the others, 

 as it is in the Orthoptera. The Jlexor muscle is attached to this 

 sclerite, which serves also to plicate the wing of those forms that fold 

 the anal region. When the fourth axillary {4'^x) is present it articu- 

 lates with the posterior wing process of the notum (PA^P), and inter- 

 venes between the latter and the third axillary. When it is absent 



