184 Ittinois NaturAL History Survey BULLETIN 
Abdominal sternites 8 and 9 usually en- 
tirely without brown, median marks at 
anterior margins, occasionally a small, 
median, brown dot at anterior margin 
of sternite 9....... 14. maculipennis 
8. Dorsum of abdomen uniformly dark 
brown, entirely or virtually without 
light markings; caudal filaments gray. 
BF re ees 12. umbratica 
marked pattern of fairly large, white 
spots; caudal filaments tan or brown. .9 
9. Abdominal sternites 1-8 uniformly light 
tan, sternite 9 with lateral and posterior 
margins shaded with dark brown..... 
i 18. aphrodite 
Abdominal sternum white, with brown 
markings on sternites 2-9......... 10 
10. Abdominal sternites 2-8 each with an 
irregular, brown crossband at anterior 
iseeineres.) Apes oece 11. perfida 
Abdominal sternites 2-8 each with a pair 
of fairly large, sublateral, brown spots 
D SESS) ee eee ee er 13. hebe 
PERSIMPLEX Group 
1. Heptagenia persimplex McDunnough 
Heptagenia persimplex McDunnough 
(1929:179). 
This species often has been confused with 
Anepeorus simplex. As McDunnough has 
pointed out (1929:179), even Walsh’s type 
material of simplex included specimens of 
persimplex. I have seen specimens of per- 
simplex in several collections identified as 
simplex. 
Mave.—Length of body 6-7 mm., of fore 
wing 7-8 mm. Compound eyes separated on 
meson by a space as wide as one compound 
eye; head very light yellow-brown; eyes in 
life light gray. Thorax very light cream 
color, almost white; legs light yellow, with 
apexes of tibiae and tarsi darkened with 
dirty tan; fore tibia as long as fore femur, 
fore tarsus one and one-third times as long 
as tibia, first tarsal segment one-third to 
almost one-half as long as second segment; 
wings hyaline, with veins and crossveins in 
costal half of fore wing light brown. Abdo- 
men light cream colored, without darker 
markings; genitalia, fig. 363, light cream 
colored, forceps segments 3 and 4 of the 
same length, and their combined lengths 
slightly less than one-half as great as length 
of second segment; caudal filaments almost 
white. 
NympuH.—Unknown. 
This species is known from Illinois, Iowa, 
Missouri, Nebraska, and Ohio. 
Vol. 26, Art. 1 
Illinois Records. — Havana: Matanzas 
Beach, June 20, 1947, Ross & Stannard, 1 @ ; 
at light, June 25, 1898, C. A. Hart, 12. 
Mount CarMEL: June 18, 1947, B. D. 
Burks, 1¢. Quincy: Mississippi River, 
June 7, 1939, Burks & Riegel, 14 ; July 6, 
1939, Mohr & Riegel, 2. SHAWNEETOWN: 
at light, June 21, 1927, Frison & Glasgow, 
34. 
ELEGANTULA Group 
2. Heptagenia diabasia Burks 
Heptagenia diabasia Burks (1946:610). 
Mate.—Length of body 9-13 mm., of fore 
wing 8-12 mm. Compound eyes pearl-gray, 
with a faint, yellow-green tint, the two eyes 
separated on meson by a space almost as 
wide as median ocellus; head yellow, shaded 
with light red on vertex and with a minute, 
black dot at base of frontal shelf at either 
eye margin. Thorax yellow, with tan shad- 
ing on dorsal meson; legs yellow, with red- 
brown shading at apexes of middle and hind 
femora and at middle and apex of fore 
femur; all tibiae shaded at bases and apexes 
with brown; fore tibia slightly longer than 
fore femur, fore tarsus one and one-fifth 
times as long as tibia, first tarsal segment 
one-fourth as long as second; wings hyaline, 
with veins and crossveins brown, and cross- 
veins in costal and subcostal interspaces 
slightly thickened; stigmatic crossveins of 
fore wing occasionally partly anastomosed. 
Abdomen yellow, with a longitudinal, black 
spiracular line on either side, a narrow, 
black, transverse line at posterior margin 
of each tergite, and apical three tergites 
shaded with golden- or carmine-brown; 
genital forceps light yellow, penis lobes, fig. 
364, tan; third forceps segment one-third 
longer than fourth, second segment four 
times as long as third; caudal filaments 
white, with brown articulations. 
FEMALE.—Length of body 9-14 mm., of 
fore wing 10-15 mm. Color lighter than in 
male, almost white; black markings of head 
and abdomen as in male; apical abdominal 
tergites without brown shading; apical ab- 
dominal sternites shaped as shown in fig. — 
362; caudal filaments white, articulations 
brown. 
NympH.—Fig. 383. Length of body 8-15 — 
mm. Each tarsal claw with large basal — 
tooth, apical denticles wanting. Dorsum of 
