□4 
THE STUDY OF INSECTS . 
and the angle between the outer margin and the inner mar¬ 
gin (Fig. 78, c ) is the a 7 ial a?igle (a'nal). 
There have been many different sets of names applied to 
the veins of the wings. Not only have the students of each 
Fig. 78.—Fore wing of a butterfly with the veins and cells numbered. 
order of insects had a peculiar nomenclature, but in many 
cases different students of the same order of insects have 
used different sets of terms. This condition of affairs was 
incident to the beginning of the science, the period before 
the correspondence of the veins in the different orders had 
been worked out. But now the time has come when it seems 
practicable to apply a uniform nomenclature to the wing veins 
of all orders; and the following set of terms is proposed for 
that purpose. 
The principal veins of the wing, those that arise at or 
near the base of the wing, are termed, beginning with the 
one lying on the costal margin, the costa (cos'ta), the subcosta , 
the radius (ra'di-us), the media (me'di-a), the cubitus (cu'bi- 
tus), and the anal veins . The radius, media, and cubitus are 
usually branched, and there may be several anal veins. 
In addition to the principal or longitudinal veins, there 
may be a greater or less number of cross-veins — veins extend¬ 
ing transversely from one longitudinal vein to another. 
