162 



RAPHIDIID^E. M ANTISPID^E. PHRYGANEID^. 



746. The RAPHIDIHXE are commonly known as Snake-flies, 

 from the elongated form of the head and neck, and the facility 

 with which they move the front of the body in different direc- 

 tions. They are of comparatively small size, agile in their 

 movements, and possessing powerful jaws ; they are chiefly 

 found in the neighbourhood of woods and streams; and they 

 prey upon other insects inhabiting the same situations. Finally, 

 the MANTISPID^: seem to connect this order with the preceding ; 

 having the mouth formed upon the plan of that of the Neurop- 

 tera ; but having the fore-legs converted into prehensile claws, 

 and the first segment of the thorax lengthened so as to elevate 

 them, almost exactly as in the Mantis. 



747. We shall next mention the small intermediate group of 

 PHRYGANEIDVE, or Caddice-flies, which are by some entomolo- 

 gists regarded as constituting an aberrant family of the Neu- 

 roptera, whilst others raise them into the rank of a distinct 

 Order, TRICHOPTERA, a name derived from the hairy covering 

 with which their wings, as well as their bodies, are beset. In 

 this character, as also in the arrangement of the nerves of the 

 wings, they bear a certain resemblance to the Lepidoptera. 



748. These Insects are chiefly 

 remarkable on account of the 

 habits of the larvae, which are 

 well known under the name of 

 Caddice-worms. These reside 

 in cylindrical cases, open at 

 B each end, to which they attach 

 various matters, as bits of stick, 

 weeds, pebbles, or even small 

 living shells, by the assistance 

 of silken threads, which they 

 spin from the mouth. These 

 cases they bear about with 



them ; protruding the three first segments, with their legs, when 

 they creep forwards ; and withdrawing these upon the slightest 

 alarm. They are never known to quit these cases of their 

 own accord. Different species appear to prefer different ma- 



FIG. 481. PHRYGANEA GRAXDIS. A, Larva in its 

 case ;B, grating ; c, Imago. 



