LAET^ OF WATEE-FLIES. 



259 



aqTiarium, as it is found in stagnant as well as running water. 

 THs species is one of the commonest of the Perlidce. The 

 Perlidce are frequently called " Stone-flies." Some fisheimen, 

 however, only recognise the Perla bieaudata, a brownish insect 

 nearly lin. long, as the " Stone-fly." 



Fig. 15B. Stone-flies, a, Male; 6, Female. 



While hunting for fresh-water aaimals, one not seldom comes 

 across an insect wrapped up in two or more green leaves or 

 pieces of leaves of some aquatic plant. The leaves and the 

 animal have somewhat the appearance of a caddis-worm in its 

 case ; in fact, for a time before I knew what it was, I mistook 

 it (and I dare say others 

 have done so also) for a 

 caddis-worm. It does not 

 however, belong to the 

 Trichopiera, but is a cater- 

 pillar of a small moth 

 commonly known as a 

 "China Mark." The "China 

 Marks " are remarkable for 

 being the only moths whose 



caterpillars are aquatic. There are only five species of 

 these moths in Britain, the largest of which is not 

 more than lin. across its expanded wings. These moths 

 have white wings, with black, brownish, or yellowish mark- 

 ings. The females deposit their eggs upon aquatic plants, 

 and the lai-vse generally seem to eat their way into the interior 



s 2 



Fig. 159. Creeper, Larva op the 

 Stone-fly. 



