THE WINGS OF EMBIIDINA 



263 



The alternating brown and pale bands give the wing a very characteristic 

 appearance (Fig. 259, A). 



In those forms where the venation of the wings has been reduced by the 

 atrophy of veins, the brown bands persist after the veins have faded out ; 

 hence it is easy to determine by these bands the former position of veins 

 that have beefi lost. In Figure 259, A represents the appearance of a wing 

 of Oligotoma sann-dersi; B, the existing venation; and C, a restoration of 

 the venation based on a study of the brown bands. Here and in other 

 figures that follow, the restored veins are indicated by dotted lines. 



On each side of vein Ri there is a narrow line of deeper color than the 

 brown bands; these lines have been termed, by Enderlein, the fore and 

 hind radial border lines (Radiussaumlinie) , respectively; these are repre- 

 sented in the following figures by series of dots, parallel with vein Ri. 



The membrane of the wing is 

 clothed throughout with fine setae, 

 and along each vein and along each 

 margin of each brown band there 

 is a series of larger setae. 



The tracheation of wings of 

 nymphs has been studied by 

 Melander ('02), who has figured 

 that of Emhia texana (Fig. 260). 

 As the order is very poorly represented in the collections to which I 

 have access, I have been forced, in my studies of the wing venation of mem- 

 bers of it, to depend almost entirely on the published figures of wings of 

 these insects. Fortunately there has recently appeared a monograph of the 

 order by Enderlein ('12) in which figures of the wings of representatives of 

 eight of the nine winged genera are given, and the wings of the remaining 

 winged genus are described in detail. The following account is based on the 

 data given by Enderlein. I have not seen the monograph of this order 

 published by Dr. H. A. Krauss ('11); but have made use of one figure which 

 is copied from it by Enderlein.* 



The wings of Embia sahulosa (Fig. 261) will serv^e to illustrate the fea- 

 tures of the wing-venation most commonly found in the wings of insects of 

 this order. The subcosta is well-preserved, but is unbranched; the radial 

 sector arises near the base of the wing and is only three-branched, veins 



M,+, 



Fig. 260. — Wing of a pupa of Emhia texana 

 (After Melander). 



*In copying the figures of Enderlein I have made some sHght changes in the lettering 

 of the wing-veins. The vein that he designates the "Cubitalstamm {cast)" is vein Cuo; 

 the accessory veins borne by vein Cui I have designated as Cuia and Cuib instead of 

 Cu2 and Cu3, his vein Cu2 in this case is not homologous with the vein Cu2 of the uniform 

 terminology; and the vein that he designates as the "Axillaris (a.v)" is the second anal 

 vein of the uniform terminology. The modification of the terminology of the veins 

 of the anal area by this author is discussed in the chapter on the wings of the Plecoptera 

 (p. 248). When media is two-branched, the two branches are doubtless veins Mi-1-2 and 

 Ms-f 4, and not veins M 1 and Mo as labeled by Enderlein. 



