194 Ittinois NarurAL History SurvEY BULLETIN 
18. Heptagenia aphrodite McDunnough 
Heptagenia aphrodite McDunnough 
(1926a:194). 
Mate.—Length of body 6 mm., of fore 
wing 7 mm. Head with face yellow, vertex 
red-brown, with black shading around ocelli 
and at posterior margin; compound eyes 
separated on meson by a space as wide as 
one eye. Thorax with pronotum yellow, 
mesonotum chestnut brown, with yellow 
shading laterally; pleuron yellow, with a 
broad, red-brown, longitudinal stripe above 
coxae; sternum yellow; legs yellow, each 
femur shaded with tan at apex, fore femur 
also with a black, apical streak; wings hy- 
aline, all longitudinal veins but C, Sc, and 
R, of fore wing colorless, crossveins of fore 
wing anterior to Cu, brown, those in costal 
and subcostal interspaces surrounded by 
brown clouds. Abdomen yellow, tergites 
1-7 each with a black, transverse line at 
posterior margin and a pair of large, brown, 
elongate, sublateral triangles; terminal three 
tergites very dark brown; genitalia, fig. 380, 
light yellow; caudal filaments light yellow 
in color. 
FEMALE.—Length of body 6-7 mm., of 
fore wing 7-8 mm. Coloration similar to 
that of male, but generally lighter. Thoracic 
notum yellow, with vague, brown darkening 
on meson at anterior margin of mesonotum. 
Abdomen yellow, tergites 1-9 each with a 
minute, transverse, black line at posterior 
margin, tergites 2-7 each with a pair of 
sublateral, oblique, dark brown streaks; ter- 
minal abdominal sternite with posterior 
margin produced on meson in form of a 
Tudor arch; caudal filaments white. 
NympH.—Length of body 7 mm. Head 
dark brown, slightly wider than pronotum, 
three white spots at margin on either side 
just anterior to compound eye. ‘Thorax 
dark brown, with numerous white spots; 
each tarsal claw with small, acute basal 
tooth and 4-6 ventral denticles. Abdomen 
dorsally mostly brown, with white markings; 
tergite 1 mostly white, tergites 7 and 8 with 
a median, coalesced, white blotch, tergite 9 
with a white, median triangle based on an- 
terior margin; abdominal sternum uni- 
formly tan, entire margin of sternite 9 
brown; caudal filaments tan, articulations 
brown. 
This species is known from Georgia, IIli- 
nois, Indiana, New York, North Carolina, 
Vol. 26, Art. 1 
Ontario, Tennessee, West Virginia, and 
Wisconsin. 
Illinois Record—Momence: at light, 
July 17, 1914, 1¢. 
43. EPEORUS Eaton 
Epeorus Eaton (1881:26). 
The species of the genus Epeorus (s. lat.) 
can be grouped into four subgenera: Epeorus 
Eaton (s.s.), [ron Eaton (1883, pl. 24, fig. 
44), Ironodes raver (19356:32), and 
Tronopsis Traver (19356:36). The last two 
subgenera include only western species in 
North America. 
In the adult males of this genus, the com- 
pound eyes are contiguous on the meson; 
the fore leg is approximately as long as the 
body, the fore tarsus is one and one-sixth 
to one and one-half times as long as the 
fore tibia, and the first segment of the fore 
tarsus is as long as, or slightly longer than, 
second segment; the two fore tarsal claws 
are either of equal size and blunt, or un- 
equal, with the larger claw blunt and the 
slightly smaller claw hooked at the apex. 
In both sexes, the first segment of the hind 
tarsus is as long as, or slightly longer than, 
the second segment. The wing venation is 
typical for the family, fig. 319, with the 
crossveins in the basal area of the costal 
interspace of the fore wing extremely weak 
or absent and the stigmatic crossveins anas- 
tomosed or not. In the hind wing, vein M, 
diverges from M, slightly basad of the 
center of the wing. In the male genitalia, 
the forceps are four-segmented, with the 
second segment longer than the third and 
fourth segments combined; the penis lobes, 
fig. 387, are fused on the median line about 
one-half of the distance to the apexes. These 
penis lobes are simple or are provided with 
median hooks or spines; there may also be 
lateral prongs on the lobes. In the females, 
the posterior margin of the terminal ab- 
dominal sternite, fig. 361, is cleft on the 
meson. 
In the nymphs, fig. 386, the frontal margin 
of the head is not incised on the meson; the 
apical segment of the maxillary palp is en- 
larged, but relatively acute at the apex, and 
has a dense row of hairs on the outer mar- 
gin; the apex of the galea-lacinia of the 
maxilla bears three stout, curved teeth. The 
apical segment of the labial palp has a dense 
row of hairs on the outer margin and, be- 
