H. E. Jacques, How to Know the Insects, 2nd ed., Wm. C. Brown, 1947

In several orders of insects wing structures play an important part in identification. Typical wings of four of these orders are here pictured. The usual abbreviations have been employed in designating the veins as follows:—C, Costa; Sc, Subcosta; R, Radius; M, Medius; Cu, Cubitus; A, Anal.