5 4 



THE STUDY OF INSECTS. 



and the angle between the outer margin and the inner mar- 

 gin (Fig. 78, c) is the anal angle (a'nal). 



There have been many different sets of names applied to 

 the veins of the wings. Not only have the students of each 



in, in 



3 ni 3 



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. 



