KEUROPTERA. 57 



insect, no longer a dirty, sluggish, grovelling, creeping 

 thing, but an active and beautiful denizen of the air. 



The Perlidoe, or Stone-flies of the Fly-fisher, is a 

 family of small extent ; there are only a few species of 

 moderate size, and are distinguished by the posterior wings 

 being much larger than the anterior. These insects are 

 all aquatic ; the eggs are" deposited in the water ; the 

 larvae are very like the perfect insect; they are to be found 

 in great quantities under stones in rivers and ponds ; 

 they are sluggish in their movements, adhering closely 

 to the sides of stones. One of the largest of the 

 family is the Stone-fly of the angler, the Perla hicau- 

 data (Fig. 6) it appears in April; another species 

 known to hshermen in some parts as the "Yellow Sally," 

 the Ghloroperla viridis, makes its appearance in May. 

 Respiration in the larvae is carried on by means of 

 gills attached sometimes to the thorax, sometimes to the 

 abdomen. None of the British Perlidoe are distinguished 

 for much beauty of colour, but some exotic kinds are 

 richly tinted, such, for instance, as the Eitsthenia Spec- 

 talis of Westwood, an Australian species, with pink 

 and violet-tinted wings, of which insect M. Pictet's 

 figure is before me as I write. 



The EijhemeridcG or May-flies, so well known to the 

 Fly-fisher, are distinguished by the small size of their 

 hinder wings and their antennae, by the absence of a 

 true mouth — for the organs are in a very rudimentary 

 condition — and by two or three long hair-like ap- 

 pendages at the end of the tail. The family consists of 

 several genera ; the best known species being the 

 Ephemera vulgata, the yellow and grey drake of the 

 angler. Some of the small kinds belonging to the 



