THE YELLOW SALLY 73 



a small nervure, absent in maxima, is usually 

 to be found in cephalotes. It must be noted, 



, . , , . . .... cephalotes. 



however, that neuration is very variable m 

 all the PERLID.E, and that this is not a 



FiG. 41. Perla cephalotes, 9 , hind wing. 



constant character. I give drawings of the 

 posterior wings of each species in Figs. 40 

 and 41 respectively. 



The stone-fly is frequently and erroneously 

 termed mayfly in the north. 



Family . . PERLIM: 

 Genus . . Chloroperla 

 Species . . grammatica 



PLATE XV 



Chloroperla grammatica, the yellow sally, is 

 one of the few PERLID.E really abundant on the 

 Test ; on other chalk-streams I have found it saUy * 

 in far smaller numbers. It may be recognised 

 by its yellowish-green colour, its characteristic 

 shape., together with the presence of 



