72 THE STONE-FLIES 



mentary wings, and is incapable of flight. The 

 PERLODES only other Perlodes found in this country is recta, 

 which is very similar in general appearance, 

 but smaller, and with a somewhat differently 

 shaped head, besides being marked differently 

 on the head and thorax. 



Family . . 

 Genus . . Perla 

 Species . . maxima 



PLATE XIV 



The nymphs or larvae of Perla maxima (the 

 stone-fly" of the North) with those of P. 

 & y- cephalotes, a closely allied species, share the 



The creeper, fisherman's name, "creeper," and are fished 



FIG. 40. Perla maxima, 9 f hind wing. 



with deadly effect on north-country streams 

 at suitable times of the year. 



The two species are very much alike, both 

 in size and in colour. Mr. Morton has pointed 

 out that the female insects may be separated by 

 the examination of the posterior wings, where 



