May, 1953 
shaded with brown; tergites 2-6 each with 
a transverse, black streak at posterior mar- 
gin and a pair of large, posterolateral, 
brown triangles; apical three segments 
brown; genitalia, fig. 374, with forceps pale 
yellow, shaded with brown toward apexes, 
penis lobes tan; caudal filaments white. 
FEMALE.—Size as in male; color gener- 
ally identical with that of male except that 
brown shading is less intense; posterior 
margin of terminal abdominal sternite pro- 
duced, and evenly rounded from side to side. 
NympH.—Length of body 9 mm. Head 
and dorsum of body extremely dark brown, 
with lighter markings obscure or virtually 
wanting; each tarsal claw with a small 
basal tooth and a few ventral denticles; 
gills uniformly dark purplish gray, those of 
seventh pair lacking ventral, filamentous 
tufts; caudal filaments dark gray. 
Known from Quebec. 
13. Heptagenia hebe McDunnough 
Heptagenia hebe McDunnough (19245:122). 
Ma te.—Length of body 6-7 mm., of fore 
wing 7-8 mm. Frontal shelf of head stained 
with brown, a black, transverse streak across 
base of shelf; face yellow, vertex brown; 
the compound eyes pearl-gray, separated on 
meson by a space slightly wider than a 
lateral ocellus. Thorax yellow-brown dor- 
sally, pleura yellow, with a longitudinal, 
brown streak just dorsad of each coxa; 
sternum yellow. Legs yellow, apexes of 
femora shaded with tan; an obscure, dark 
brown, ventral streak usually present near 
apex of each femur; fore tibia shaded with 
tan in apical half, fore tarsus tan; first fore 
tarsal segment one-fifth as long as second 
segment; wings hyaline, all veins of fore 
wing tan, crossveins dark brown, those in 
costal and subcostal interspaces surrounded 
by a dark brown cloud, another cloud at 
base of outer fork; often these clouds sur- 
round virtually all crossveins in fore wing; 
veins and crossveins of hind wing hyaline. 
Abdomen yellow, tergum heavily shaded 
with dark brown, this shading sometimes 
uniformly and completely covering tergites, 
but usually tergites 2, 3, and 8 each with a 
pair of submedian, yellow streaks, tergites 
4-7 each with large, round, median, yellow 
spot; genitalia, fig. 375, yellow, with median, 
discal spines extremely long; caudal fila- 
ments light yellow. 
Burks: THE MAyrtiss or ILLINoIs 
191 
FrmMALeE.—Length of body 5-6 mm., of 
fore wing 7-8 mm. Head almost entirely 
yellow. Thorax yellow, with dark brown, 
longitudinal stripe on each pleuron above 
coxae; legs light yellow, fore femur lightly 
shaded with tan; wings with crossveins in 
costal and subcostal interspaces surrounded 
by dark brown clouds, other crossveins in 
fore wing dark brown, veins white or a 
faint yellow. Abdomen light yellow, with 
a pair of broad, submarginal, lunate, dark 
brown streaks on each of tergites 1-7; pos- 
terior margin of terminal abdominal sternite 
produced, evenly rounded from side to side; 
caudal filaments white. 
NympH.—Length of body 5-7 mm. Head 
brown, with dark brown freckles and three 
white spots on margin just anterior to either 
eye, and a pair of submedian, white spots on 
posterior margin of vertex. Thorax brown, 
with numerous small, white spots; each tar- 
sal claw with a small, acute basal tooth and 
3-5 ventral denticles. Dorsum of abdomen 
brown, with prominent, white markings; 
tergite | almost entirely white, tergite 2 
white on median area and on posterolateral 
triangles, tergites 3 and 6 each with four 
white dots, tergites 4 and 5 white on broad, 
median area and on lateral triangles at 
posterior margins, tergite 7 white across 
posterior half, tergite 8 almost entirely 
white, tergite 9 with a white stripe across 
anterior margin and with a pair of circular, 
posterolateral, white spots, last tergite with 
a median, white spot at posterior margin; 
venter entirely white except for a brown 
mark at each posterolateral angle of ter- 
minal abdominal sternite; gills borne by 
seventh segment without ventral, filamen- 
tous tufts; caudal filaments tan, alternating 
articulations brown. 
Known from Connecticut, Illinois, Indi- 
ana, Iowa, Maryland, Michigan, Minne- 
sota, New York, Ohio, Ontario, Pennsyl- 
vania, Quebec, and Tennessee. 
Illinois Records. — Downs: Kickapoo 
Creek, June 22, 1943, H: H. Ross,1?@. 
ErcHorN: June 6, 1946, Mohr & Burks, 
1¢. Homer: Salt Fork River, June 30, 
1925, T. H. Frison, 42; July 19, 1924, 
T. H. Frison, 12. KANKAKEE: Kankakee 
River,” June, 17,. 1939, )B. D: Burks, 124 
Julyl0: 919255 13) 5+ Tuly 110; 1925, TH. 
Frison, 36, 29. LA GRancGE: June 17, 
1938, J. S. Ayars, 26. Mazon: Mazon 
Creek, June 23-28, 1938, Ross & Burks, 
