PLECOPTERA NYMPHS OF NORTH AMERICA 57 
Female. Tenth abdominal tergite broadly rounded but without 
median tubercle; genital opening indicated on the eighth ab- 
dominal sternite. 
The nymphs of this species occur in small upland spring brooks, 
where they may be collected under stones. I have never collected 
them in the large swift-water streams. The more or less cylindric 
shape of the body is not so well suited for inhabiting the swifter 
waters, and yet the total absence of gills necessitates their living 
in cold spring brooks in which the water maintains a steady flow 
and is richly supplied with oxygen. 
The nymphs are carnivorous and apparently require two years 
to complete the life eyele. 
Ithaca, N.Y. 
Perla verticalis (?) Banks 
(Plate 4, figs. 55-59; plate 15, fig. 189.) 
Length of body up to 12 mm.; antennae up to 6.5 mm.; cerei 
up to 7.5 mm 
General color yellow with a wide blackish transverse band 
across the head; pro-, meso- and metanotum yellow in the middle 
and dark all around except the tips of the wing pads, which are 
yellowish ; abdomen transversely banded with yellow and brown. 
Head much wider than pronotum, especially so because of the 
large protruding maxillae, which are plainly visible from above; 
a wide, transverse, dark band bounded in front by the M-line, 
and in the rear by the epicranial suture; rest of head more or less 
yellow; hind ocelli a little closer to the eyes than to each other; 
antennae at least half as long as body and composed of about fifty 
seoments; occipital ridge absent. 
Pronotum almost transversely oval; less than twice as wide as 
long; marginal groove distinct, continuous all around, and as 
near the margin on the sides as in front and rear; middle field 
yellow, rest dark brown or blackish; meso- and metanotum yel- 
low in the center and blackish around the border ; wing pads most- 
ly yellowish and with the outer margins about parallel with the 
body. Legs long and slender, mostly yellow, but usually with a 
dark area on the femora and with a rather thin fringe of long 
hairs; tarsal claws with sharp basal tooth. 
Abdomen not much flattened; tergites yellow, with the basal 
part brown, but sometimes the posterior margin also brown; tenth 
tergite blackish at base. Cerci more than half as long as body; a 
fringe of long hairs on the dorsal line and each segment termi- 
nating in a whorl of spines; about twenty-five segments. 
Gills absent. 
