PHRYGANEA. 25 



notice, for the neatness with which it forms its 

 case. It is made of the leaves of duck-weed, 

 w T hich is found in such abundance floating on 

 the surface of the water. These leaves might 

 do very well in their original shape ; but the 

 insect, dissatisfied with their appearance, cuts 

 them into very regular square pieces, and joins 

 them end to end, so as to form a spiral habi- 

 tation, somewhat resembling a green ribbon 

 rolled upon a cylinder. These larvae in general 

 are well known to fishermen by the name of 

 Cadis, and are an excellent bait for many fish. 



The larva prepares for the usual change by 

 projecting its case a little above the surface of 

 the water, and fixing itself by silken threads to 

 a water-plant. In this state it becomes a chry- 

 salis ; and in about a fortnight or three weeks 

 a winged and perfect insect. 



SPECIFICATION. 



Phryganea grandis. P. alis cinereo-testaceis : 

 lineolis duabus longitudinalibus nigris : puncto 

 albo. Linn. Syst. Nat. p. 909. Gmel. p. 26SS. 

 VOL. II. D 



