September, 1942 FRISON: 
Perla bilobata’ Claassen 
Nymphal description. 
Claassen’s (1931) description of the 
nymph of this species was based upon 
-nymphal skins from “Old Forge, New 
York,” and, although the mouthparts were 
illustrated, no illustration of the entire 
nymph was presented. 
During the course of field work near 
Gatlinburg, Tenn., in 1930, numerous 
nymphs of this species were collected and 
both males and females reared. Since no 
illustration of this nymph exists in liter- 
ature, fig. 7+ is presented. The unusual 
(193 18s mes le 
Fig. 74.—Nymph of Diploperla bilobata. 
appendage at the end of the abdomen in 
the nymphal male, lacking in the female, 
Was not noted by Claassen in his descrip- 
tion. The mouthparts of the nymph are 
as in fig. 75. 
NortH AMERICAN PLECOPTERA 
303 
NYMPHAL 
MANDIBLES 
NYMPHAL 
LABIUM 
oy 
Fig. 75.—Diploperla bilobata. 
Records for this species in the Illinois Nat- 
ural History Survey collection are as follows. 
TENNESSEE.—Great Smoky Mountains Na- 
tional Park, GATLINBURG: June 14, 1940, 
Frison et al. 22, 1 exuvia, 4 nymphs; June 
17, 1940, Frison ef al. 12; June 18, 1940, 
Frison et al. 19 with exuvia (reared) ; June 
19, 1940, Frison et al. 29 with exuviae 
(reared), 16; June 20, 1940, Frison et al., 
19 with exuvia (reared); June Ze 940) 
Frison et al., 1Q with exuvia (reared) ; June 
24, 1940, Frison et al., 19 with exuvia 
(reared), 29 ; Le Conte Creek, May 14, eae 
Frison & Ross, 7 nymphs; Le Conte Creek, 
June 14, 1940, Frison et al.. 28, 49; Cades 
Cove, June 13, 1940, Frison et al., 19 with 
exuvia and 14 with exuvia (reared), many 
nymphs; Fighting Creek Gap, May 15, 1939, 
Frison & Ross, 1 nymph. 
NorTH CAROLINA.—SMOKEMONT, Oconaluftee 
Creek: May 28, 1934, T. H. Frison, 1 nymph. 
Macon County: Big Creek above Lake Ran- 
dall, June 20, 1939, Thelma Howell, 1 nymph; 
Nantahala River, May 30, 1939, Thelma How- 
ell, 1 nymph. BarsaM: April 24, 1938, Ross 
& Burks, 9 nymphs. 
Diploperla modesta (Banks) 
Perla modesta Banks (1908a, p. 255). Orig- 
inal description, ¢, 9. 
It was my good fortune in August, 
1940, while in Wyoming, to rear several 
male and female specimens of modesta 
and thus definitely associate the nymph of 
this species with its adult. Since the 
nymph has not been previously described 
or illustrated, at least under the name 
modesta, | am presenting the following 
description. 
