198 



Aquatic Organisms 



Fig. 104. Caddis-worms: larva? of Hales us guttifer. 



creature, half soft and pale 

 where constantly protected by 

 the walls of the case in which 

 it lives, and half dark colored 

 and strongly chitinized where 

 exposed at the ends. There 

 are stout claws at the rear 

 for clutching the wall of the 

 case; there are soft pale fila- 

 mentous gills arranged along 

 the side of the abdomen, and 

 there are three spacing tuber- 

 cles upon th^ r ~st segment 

 of the abdor uring 



that a fresr. vater 



shall be du ^ase 



co flow ovc The 



legs are direo ..»rward, for 



F*g. 105. The larval case of 

 T ; mnophilus, attached end- 

 . .. to a submerged flag leaf, 

 in posi " f transformation. 



