AQUATIC INSECTS IN NEW YORK STATE 241 
This is our largest species. It was not common at Saranac 
Inn, though a few could be found at any time about the timbers 
by the shores of the larger ponds. I bred it there. I had pre- 
viously bred it at Ithaca, where it is very common, and during 
the summer of 1901 I bred from Fall creek many additional 
examples. The species is a common and characteristic one 
about the shores of the great lakes. It belongs on wave-beaten 
shores and in the larger and more rapid streams. In Fall creek 
its nymphs are found under stones in even the swiftest water,. 
clinging, as stone flies cling, to the rocks. It is the only dragon 
fly to be found inhabiting such situations. 
Kellicott made some interesting observations on the species. 
at Lakeside on Lake Erie. The species was ovipositing in pairs 
on the dock timbers. The females would sometimes descend the 
timbers into the water, carrying the males with them. The 
females would remain submerged a long time (once almost an 
hour) while ovipositing, but the males would disengage them- 
selves and come up out of the water after 5 to 20 minutes. The 
descent is made by the backing downward of the female as she 
reaches ever for new territory in which to distribute her eggs. 
Nymph. Length 17mm, gills 6mm additional, abdomen 10mm; 
width of head 4mm. Antennae seven jointed, the second joint 
one third longer than the first. The single raptorial seta of 
the lateral lobe of the labium is very minute, difficult to see at 
all. The median lobe of the labium is very prominent, about 
half as long as it is wide. In the center of the mentum is an 
elongate V-shaped chitinization, the V opening forward. The 
abdomen is relatively long, the wing cases reaching scarcely to 
the base of the fourth segment. The gills are more than twice 
as long as wide, with parallel margins and obtuse apexes, black- 
ish, with the apical fifth more or less covered with white. 
The head is more depressed, and the legs are more sprawling 
than in other species, due perhaps to the habitat. The stone 
flies and May flies living in rapids are modified in form along 
the same lines. At transformation the nymphs depart farther 
from the water than in the other species, often going several 
yards up the banks. 
The seasonal range for imagos of this species is from May 
«ill October. 
