TRICHOPTERA. — PHRYGANEID™®. 69 
assumes considerable activity, swimming along, as I have observed, 
by means of its two hind legs, which are strongly ciliated, and 
crawling about by means of its four fore legs, which become 
detached from the breast. M. Pictet has made some interesting 
observations on the relations of the limbs of the pupa with those of 
the larva, and of the manner in which the former are enclosed within 
the larva skin. The pupe of the larger species creep out of the water, 
crawling up the stems of plants, &c., and undergoing their final 
change in the air; but the smaller ones merely come to the surface, 
where they shed their pupa skin in the same manner as gnats, their 
old envelope serving them as a raft. 
The pupa is furnished, as well as the larva, with external respiratory 
filaments, besides which, each of the segments of the abdomen, except 
the first and last (fig. 67. 16. second abdominal segment of the 
pupa of P. striata Prcteé), is dorsally provided with a pair of 
small patches, charged with recurved points, which evidently assist 
the pupa in making its escape from the case, previous to assuming 
the perfect state. The pupx of Phryganea have also a row of 
short filaments at the sides of the abdomen, the uses of which are 
unknown. The abdomen is also terminated by various appendages, 
of which the form varies in the different groups. The perfect insects 
are of small or moderate size, seldom reaching a couple of inches in 
the expanse of the wings. They are very active, running with agility 
with a kind of gliding motion, not unlike that of certain Tipulidz, and 
other insects with long tibial spurs; but their flight is awkward, except 
in some of the smaller species, which assemble in troops, and fly over 
the surface of water towards sunset: they frequent damp marshy 
situations. From the weak structure of the mouth, it is evident that 
they can live but a very short time in the perfect state, taking no 
nourishment, and only anxious to continue their species. Their 
colours are obscure, being ordinarily brown or grey; when handled, 
they emit a very disagreeable odour. A very few exotic species are 
ornamented with spots and markings. Few, only, have been brought 
from extra-European countries. 
This order was first proposed by De Geer (to which his commen- 
tator Retzius applied the name of Elinguia), and included the Lin- 
neean Phryganee and Ephemere, which two groups were also united 
by Dumeril into his family Buccélés or Agnathes. Linnzus had 
united the Perlidee and Phryganee into one genus, from the characters 
F 3 
