PLECOPTERA NYMPHS OF NORTH AMERICA — 69 
slender; not much flattened; a thin fringe of long hairs on the 
outer margin; first and second tarsal segments very short; tar- 
sal claws each with a small basal tooth. Abdomen not much flat- 
tened; cerci at least half as long as the body. Gills absent. 
The mouth parts probably serve as the most reliable characters 
for identification of this genus. The detailed description of the 
mouth parts of C. clio applies to all three known species. 
This genus is rather closely allied to Isoperla and the gill- 
less species of Perla. The shape of the lacinia and the slender 
pointed apical segments of the maxillary and labial palpi, are 
especially helpful in the identification of the nymphs of Clioperla. 
Little is known of the biology of the nymphs but the structure 
of the mouth parts indicates that they are carnivorous. C. similis 
occurs in small upland spring brooks, and the general shape of 
the nymphs of this and the other two known species leads me to 
believe that they do not inhabit the swifter parts of the larger 
streams, but are restricted to smaller brooks. 
Key to the Species of Clioperla 
1. Western forms, almost uniformly yellowish brown but with 
Wellowsmarks on the tiead 6.0.2 ....3 50.0... ebroa (p. 71) 
Eastern forms with or without a contrasting pattern of yel- 
VOR y SBMS Lea ORy A aac iS 2a oan OO a er 2 
2. Head with a broad brown transverse band; pronotum yellow 
in the middle, surrounded by brown; abdomen transversely 
banded with yellow and brown ............... clio (p. 69) 
INOtESO sa. a, De: oad Veg hal as RU 3 ear nee similis (p. 71) 
Clioperla clio Newman 
(Plate 7, figs. 106-110; plate 19, fig. 196.) 
Length of body up to 15 mm.; antennae up to 7 mm.; cerci 
up to 8 mm. 
General color yellow and brown; head with a wavy brown 
transverse band; pronotum yellow in center with brown all 
around; sides of pronotal dise yellow; abdominal tergites brown 
with a more or less distinct middle transverse band of yellow. 
Head a little wider than pronotum, maxillae projecting out- 
ward somewhat, so as to be visible from above; a dark wavy 
transverse band passes over the front ocellus with arms directed 
backward to the hind ocelli, thus leaving an inverted V-shaped 
or rounded yellow spot between the hind ocelli; in more fully 
