98 PLATYPTERA. 



biting, the insect feeding upon lichens and dry vege- 

 tation. The legs are long and slender. The wings 

 have few veins, and when the insect is not flying are 



folded roof-like over the abdomen. The metamor- 

 phosis of the Psocidae is direct, and the larvae resem- 

 ble the adults excepting in not possessing wings. 



The book-Hce are larva-like, wingless forms of this 

 family, with strong legs suitable for running. They 

 are light-colored, minute insects common in neglected 

 books and collections. Though called lice on account 

 of their aspect, they do not resemble them in structure, 

 and are not parasites. 



MALLOPHAGID.^. 



These are minute parasites that live principally 

 on birds. They can be collected from chickens. 

 They are unlike true lice in having mouth parts for 

 biting, and they feed upon dandruff, feathers, etc. 

 Several species are found also upon mammals. 



Among the Platyptera the white ants and book- 

 lice are terrestrial in all stages, but the members of 

 the subdivision of Mallophagidae are parasites, as stated 

 above, and possess the usual specializations noticeable 



