Order PLECOPTERA. 



The "Stone flies" which constitute this order are loose-jointed, flat- 

 tened, soft-bodied creatures with long net-veined wings, the hind pair 

 longitudinally folded beneath the anterior. The head is large, the 

 mouth parts are soft, antennas long and tapering, eyes rather prominent. 

 The prothorax is free and quadrate, the other segments loosely jointed. 

 The abdomen is soft and usually with anal filaments or processes. These 

 "flies" are found along the streams and rivers in which their larvae occur, 

 resting on the leaves and not easily disturbed; their flight is heavy and 

 they do no feeding upon living plants so far as known. The larvae live 

 in streams under stones to which they cling so closely that, being very 

 much flattened they are easily overlooked. They breathe by means of 

 lateral gill tufts which occur also on the head, and which, in some species, 

 persist even in the adult stage; a curious reminder of ancient conditions 

 and an indication of the primitive character of this order! The pupae are 

 active and the transformation is incomplete. They form an important 

 feature of the aquatic fauna in numbers of individuals as well as of 

 species, but are of no economic importance. 



Since the previous edition quite a number of genera and species have 

 been taken, practically all of which have been determined by Mr. Banks. 



Fig. 5. A stone-fly and its larva. 



Famil 



PTERONARCYS Newn. 



P. nobilis Hagen. New York to Tennessee. 

 P. regal is Newn. Philadelphia, and certainly 

 occurs in New Jersey. 



(39) 



