44 



rough, with a few proininenl tubercles, in size and form resembling the scales 

 left by the falling-off of the leaves of the juniper. 



That this is an illustration of protective mimicry, of service to the species, 

 seems nol unlikely. There are so many cases of this sori among the larva' of 

 this family that il seems unnecessary to adduce other examples. 



§ 14. — Tkkminology. 



In describing the head, the term " front" applies tit the region in fronl 

 of the insertion of the antennae, while the term "vertex" applies to the por- 

 tion above and behind the insertion of the antennae. 



As regards the venation, the term "venule'' is applied to the branches ot 

 the mam veins. The branches are numbered from the first one thrown off 

 to the last, going from the costa of the wing backwards (the costa being 

 regarded as the front edge of the wings when expanded, as in flight). The 

 costa is the front edge of the wing; the outer edge is situated between the 

 apex and the inner angle; the latter situated at the end of the internal vein; 

 while the inner edge extends from near the end of the internal vein to the 

 insertion of the wing. Of the discal vein (which primarily consists of two 

 veins), the portion sent off from the subcostal vein is called the (interior discal, 

 and the venule thrown off from the median vein is called the posterior discal. 

 The vein originating from the point of union of these two veins is called the 

 independent rein by French authors. 



Of the markings on the ir/ngs, there are often four or five lines, the inner 

 of which is called the basal, the second the median or intradiscal, and the third 

 the extradiscal; while there are often a submarginal line and a marginal line, 

 the latter interrupted by the venules. See also the explanations of the plates. 



