PHYLUM ARTHROPODA 



269 



Campodea represents a very different group of Thysa- 

 nura, or perhaps distinct order; a soft, fragile white 

 animal, with two long tails instead of three. It occurs 



in damp places. 



Order Orthoptera 



Terrestrial insects with incomplete metamorphosis, Grasshop- 

 the pupa stage being active. The mouth parts are well Jfe S ' a nJ ck ~ 

 developed, for biting. The anterior wings, called teg- cockroaches 

 mina (singular, legmen), fold over the abdomen ; but in 

 many species the wings are absent. The grasshopper, 

 cricket, and cockroach are familiar Orthoptera. It will 

 be noted that some, presumably the most primitive, 

 have no power to jump, while others possess large hind 

 legs and leap vigorously. The former type is illustrated 

 by the cockroach, mantis, and earwig, the latter by the 

 grasshopper, cricket, and locust. For additional par- 

 ticulars see Chapter 42. 



Order Archiptera 



This includes 

 the stone flies 

 (Perloidea or 

 Plecoptera) and 

 the May flies 

 (Ephemeroidea 

 or Plectoptera), 

 often regarded 

 as representing 

 two distinct or- 

 ders. They are 

 winged insects, 

 with incomplete 

 metamorphosis, 

 the immature 



Stone flies 

 and May 

 flies 



From Bulletin 6~, U. S. National Museum 

 FIG. 82. A stone fly (Pteronarcys). 



