CADDIS-FLIES. 41 



small moths that they require careful examination to distinguish 

 them. 



The principal families are Phryganida, Limnophilidw, Sericosto- 



Fig. 41. 



Pupa of Caddis-fly in swimming position. 

 Twice natural size. 



matidw, Leptoceridw, (Estropsidce, Hydropsychidm, Rhyacophilidce and 



Hydropsilidce. 



Order MALLOPHAGA. 



The Mallophaga (1501-1508), commonly called Bird-lice, are 

 small, wingless insects, with flat bodies, which undergo very little 

 change in their growth to maturity. The head is large and free. 

 The mouth is furnished with strong mandibles, lodged in a cavity 

 beneath the head. The prothorax is distinct but not large. The 

 mesothorax and metathorax are often only distinguishable from the 

 abdomen by the legs being attached to them. The legs are attached 

 to the sides of the segments. The tarsi have two (rarely three) 

 joints, terminating in one or two claws. 



The majority of the species live among the feathers of birds. A 

 few are found on mammals. 



