May, 1953 
longitudinal veins of fore wing stained a 
faint yellow-brown. Abdomen uniformly 
red-brown, each segment with posterior 
margin slightly darkened; terminal abdom- 
inal sternite with a relatively shallow, broad, 
rounded, median excavation on _ posterior 
margin; caudal filaments a faint yellowish 
tan. 
NympH.—Length of body 7-8 mm. Head 
light yellow-brown, with lateral areas near 
eyes shaded with red-brown. Thorax light 
brown, yellowish laterally; legs light yellow- 
Burks: THE MAYFLIEs oF ILLINOIS 91 
genitalia, figs. 202, 204, light brown; caudal 
filaments uniformly tan. 
FEMALE.—Length of body 5-6 mm., of 
fore wing 5.5-6.5 mm. Coloration similar 
to that of male, except that red-brown re- 
places dark brown, and tan replaces light 
brown; all crossveins of fore wing, except 
those in anal and cubital areas, tan; cubital 
and anal crossveins of fore wing, and all 
crossveins in hind wing, hyaline; posterior 
margin of seventh abdominal sternite pro- 
duced posteriorly to form a long, pointed 
Fig. 212.—Paraleptophiechia praepedita, mature nymph, lateral aspect. 
brown, with brown shading near apexes of 
femora. Abdomen light brown, each tergite 
with two pairs of vaguely defined, light 
yellowish spots; gills hyaline, tracheae gray, 
with only a few, minute, lateral branches; 
posterolateral angles of tergites 8 and 9 
produced as spines; caudal filaments light 
yellow-brown. 
Known from the northeastern and mid- 
western states and eastern Canadian proy- 
inces. 
Illinois Record.—Herop: Branch Big 
Grand Pierre Creek, May 2, 1946, Burks 
& Sanderson, 1¢. 
3. Paraleptophlebia praepedita (Eaton) 
Leptophiebia praepedita Eaton (1884:99). 
Mave.—Length of body and of fore wing 
each 4.0-5.5 mm. Head very dark brown, 
almost black; eyes in life dark red-brown; 
antennae brown, each becoming hyaline at 
tip of flagellum. Thorax very dark brown, 
with yellow-brown markings on pleura; legs 
usually uniformly light brown, femora some- 
times slightly darkened; wings hyaline, each 
fore wing slightly brown-stained at base, 
longitudinal veins tan, crossveins colorless. 
Abdomen usually uniformly brown, middle 
segments sometimes slightly lighter brown 
on dorsal meson and at anterior margins; 
ovipositor; posterolateral angles of terminal 
sternite acuminate, median emargination of 
posterior margin deep and triangular; caudal 
filaments tan. 
NympH.—Fig. 212. Length of body 5-7 
mm. Head and body tan, vaguely marked 
with light yellow on dorsum of thorax; legs 
yellow, shaded with tan near apexes of 
femora, in middle of tibiae, and near bases 
of tarsi; abdominal tergum tan, marked with 
light yellow on meson and near _ postero- 
lateral angles of each tergite; abdominal 
venter yellow, with longitudinal, tan bar 
parallel with and near to each lateral 
margin; gills hyaline, central tracheal stripes 
purplish gray; posterolateral angles of ab- 
dominal tergites 8 and 9 produced as spines; 
caudal filaments uniformly tan. 
Known from the northeastern and mid- 
western states and eastern Canada. This is 
the commonest species of Paraleptophlebia 
in [linois. 
Illinois Records.—Diona: June 7, 1941, 
Ross & Mohr, 1 ¢. Eppyvitie: Lusk Creek, 
May 16-17, 1947, B. D. Burks, 1¢. Fox 
RipGE STATE Park: May 13-17, 1938, Ross 
& Burks, 66,19,1N; May 25, 1942, Ross 
& Riegel, 1¢, 2 N. Herop: May 2-9, 1942, 
Burks & Mohr, 46, 79, 16 N; May 13, 
1939, Burks & Riegel, 26 ; May 27, 1942, 
B. D. Burks, 71 6, 89 ; May 2, 1946, Mohr 
