LEPIDOPTERA. 
221 
within the discal cell. In the hind wings, veins I and II 
and veins II and III are grown together in an unusual 
way. In Figure 254 these veins are represented slightly 
separated in order to show their relation to each other. 
Family COSSID^E (Cos'si-dae). 
The Carpenter-moths . 
This family includes moths with spindle-shaped bodies, 
and narrow, strong wings, some of the species resembling 
Hawk-moths quite closely in this respect. The larvae are 
wood-borers, living in the solid wood of the trunks of trees. 
They are often very injurious to forest or shade trees, and 
one recently imported species is very injurious to pear trees. 
The wood-boring habits of the larvae suggest the popular 
name Carpenter-moths for the insects of this family. 
These moths fly by night, and lay their eggs on the bark 
Fig. 255.—Wings of Prionoxy'tus robinite ; /\ frenulum, enlarged. 
of trees, or within tunnels in trees from which adult Car¬ 
penter-moths have emerged. The caterpillars are nearly 
naked, and, although furnished with pro-legs as well as true 
legs, are grub-like in form. The pupa state is passed within 
