May, 1953 
Fig. 383. — Heptagenia diabasia, mature 
nymph, dorsal aspect. 
abdomen uniformly dark brown, with mi- 
nute, submedian and anterolateral, light 
spots on tergites; abdominal sternites white, 
with a wide, brown, sublateral, longitudinal 
| band near either lateral margin; gills, fig. 
325, relatively slender, with filamentous tuft 
prominent and bushy, gills borne by seventh 
segment with well-developed, filamentous 
Burks: THE Mayer ies oF ILLINOIS 185 
tuft; caudal filaments rather vaguely 
marked with alternating, narrow, dark and 
light color bands. 
Known from Illinois, Iowa, and Minne- 
sota. 
Illinois Records.—Catro: July 12, 1948, 
L. J. Stannard, 1¢. Dixon: June 25, 1947, 
B. D. Burks, 1 ¢. East Dusugue: July 3, 
1946, Burks & Sanderson, 192. FREEPORT: 
June 10-11, 1948, Burks, Stannard, & Smith, 
16. Havana: June 17, 1909, 192; June 1, 
1933, at light, C. O. Mohr, 1 ¢ ; White Oak 
Creek, near Matanzas Lake, June 2, 1940, 
B. D. Burks, 4¢, 12; Matanzas Beach, 
June 25, 1947, Ross & Stannard, 52, 29. 
Homer: July 4, 1943, H. H. Ross, 1¢. 
Homer Park: June 30, 1925, T. H. Frison, 
1Q. JERSEYVILLE: June 2, 1938, T. H. Fri- 
son, 16. KANKAKEE: Aug. 3, 1938, Burks 
& Boesel, 1¢. Kappa: June 22, 1943, H. 
H. Ross, 1 6. MAnomert: June 8, 1940, H. 
H. Ross, 1 ¢. Mazon: Mazon Creek, June 
25-27, 1938, B. D. Burks, 36,29. MuLan: 
Rock River, June 4, 1940, Mohr & Burks, 
58,292. Momence: June 22, 1938, Ross 
& Burks, 16. Mount CarMet: June 18, 
1947, B. D. Burks, 16, 19. Muncie: 
May 22, 1942, Ross & Burks, 1 ¢. Peoria: 
June 23, 1938, F. F. Hasbrouck, 1 ¢. Rock- 
FORD: June 12, 1938, at light, Ross & Burks, 
13; June 29, 1938). at heht; BUD. Burks; 
1g; June 11, 1948, Burks, Stannard, & 
snith, 13'¢,-19> Sr. osupn: July ~29; 
1922, °T 4He *Frison,- 197 
PULLA Group 
3. Heptagenia pulla (Clemens) 
Ecdyurus grandis Clemens (1913:147). 
Nomen nudum. 
Ecdyurus pullus Clemens (1913:330). 
Mate.—Length of body 10-11 mm., of 
fore wing 11-12 mm. Head light yellow, 
with a transverse, brown mark crossing face 
below antennal bases, and vertex shaded 
with brown. Pronotum dark brown; meso- 
notum and thoracic sternum light red-brown, 
pleura yellow. Legs yellow, with apexes of 
femora and bases of tibiae red-brown, tarsi 
with articulations stained with red-brown; 
wings hyaline, veins and crossveins of each 
fore wing brown. Abdomen yellow, tergites 
shaded with red-brown on broad, longitu- 
dinal, median area, this dark area inter- 
rupted by a narrow, yellow, median line and 
