ORDER PLATTPTERA. 



67 



Family Perlidae. Body long and flat; prothorax square; antennae 

 long and thread-like; abdomen ending in two long stylets; wings 



FIG. 51. A Perlid (Nemoura). a, pupa (nymph) and imago. 



with transverse veins, and folded flat on the back. The larvae and 

 pupae active, living under stones in streams, the imagines frequent- 

 ing damp, shady places by water- courses. Perla abnormis Newman; 

 Pteronarcys regalis Newman. 



Family Psocidae. Small insects, with short cylindrical bodies, a 

 small prothorax, and a swollen clypeus, resembling 

 Aphides; wings small, deflexed, with few veins; 

 living on lichens, etc., and on the under side of 

 leaves. Psocm novce-scotue Walker, Caecilius (Fig. 

 52). The book-louse, Atropos pulsatorius (Linn.), 

 is wingless; it is sometimes called the "death- 



FIG. 52. Ccecilius. FIG. 53. Atropos 



pulsatorius. 



watch" or " death-tick," from being erroneously supposed to make a 

 ticking noise like the Auobium beetle. It is common in books, 

 and is injurious to cabinet specimens of small moths and other deli- 

 cate insects. 



Family Embidae. Body long, flat, and narrow; wings with few 

 veins. Embia savigni Westw., Egypt, none in the U. 'S. 



Family Termitidae. The white ants in some features closely re- 

 semble the cockroaches, but they are smaller, with narrower bodies 



