ote 
apical tergites are not visible in ventral 
view, eighth sternite with a prominent 
rounded lobe in middle of posterior mar- 
gin. 
Legs with first and second tarsal seg- 
ments together shorter than third; first 
tarsal segment slightly longer than second. 
Wings slightly suffused with brown; 
veins uniformly dark brown. 
Length to tip of wings 11 mm. ; length 
to tip of abdomen 8 mm. 
FEMALE.—Head, thorax and basal ab- 
dominal segments and appendages in gen- 
eral similar to those of male but slightly 
larger in size. Important differences are 
as follows: eighth abdominal sternite, fig. 
104, with subgenital plate slightly pro- 
duced over ninth sternite and rounded. 
Holotype, male. — Silva, Wayne County, 
Mo.: reared April 8, 1938, from nymph col- 
lected April 7, 1938, T. H. Frison & Caro: 
Mohr. 
Allotype, female—Same data as for holo- 
type. 
Paratypes.—MussourI.—SILVA: Same data as 
for holotype, 11¢, 142. Same data as for 
holotype except date (all 1938): Aprile, Won 
April 12, 22; April 16,14, 49. Zion, Madi- 
son County: reared April 15,14, 29; April 
18,14, 2@ ; April 20, 16 ; April 21,138, 19; 
April 22, 19; April 24, 19; all collected as 
nymphs, April 7, 1938, by T. H. Frison & Carl 
O. Mohr, and reared. 
INpIANA.—McCorMICKk’s CREEK STATE PARK: 
April/16, 1938-26, 19 p April 2391938) 1 5 
all reared from nymphs collected April 16 
byl. sia rison, 
Nympu. — General color pale yellow 
with fuscous areas on head, thorax and 
abdomen, as in fig. 105. Legs, antennae 
and anal cerci pale yellow. Head with 
ocelli forming an almost equilateral tri- 
angle; basal segments of mouthparts not 
conspicuously extending out, from sides of 
head. Labium, mandibles and maxillae 
as in fig. 104. 
Pronotum broader than long with mark- 
ings as in fig. 105. 
Abdominal tergites having general back- 
eround creamy yellow with fine, longitudi- 
nal, dark stripes, one in middle and one 
on each side, a series of prominent, small, 
dark spots associated with dark stripes, fig. 
105; some scattered, stout, short, pale 
setae on tergites in addition to row on 
posterior margin of each segment. Cerci 
long, many segmented, segments progres- 
sively longer from base to apex; a longi- 
tudinal row of long, fine setae on dorsal 
surface of apical segments in addition to 
Ituinois NaturaL History SURVEY BULLETIN 
Vol. 22, Arta 
smaller spinelike ones encircling apex of 
each segment. 
Approximately mature specimens with 
body length of 9 mm. j 
No thoracic, anal or submental gills. 
Nymphal records are as follows. ; 
INDIANA.—McCorMIck’s CREEK STATE PARK: 
April 16, 1938, UH: Frison, 6 nymphs. 
MIssOURL—SILVA, Wayne County: April, 
7, 1938, T. H. Frison & C. O. Mohr, 17 
nymphs; March 27, 1937, T. .H.. Frisonya3 
nymphs. 
The general shape of the subgenital 
plate of the female, the lobe on eighth 
sternite of male and subanal lobes of male, 
as well as general pattern of fuscous mark- 
ings on dorsum of adult, approach very 
closely those of signata (Banks). “That 
the species here described as new is not 
signata is definitely proved by the marked 
differences in color patterns Of jam 
nymphs; in fact, it was the distinctiveness 
of the nymphal color pattern observed in 
Es Decree Ta ee 
Fig. 105.—Nymph of Isoperla namata, 
