GEORGIAN BAY EPHEMERID^ 137 



SESSIONAL PAPER No 39b 



and projections from this band anteriorly in the median line, almost forming a 

 continuous longitudinal stripe on the abdomen; the band widens slightly laterally 

 also; remaining portions of each segment somewhat light brown; ventrally very 

 slightly banded. Forceps and penis lobes of usual form. Femora banded in middle 

 and at distal end. Wings large; costa, subcosta and radius light in colour while 

 remainder of longitudinal and the cross veins brown. No cloud in pterostigmatic 

 space. 

 Female imago: v 



Measurements: Body 10-12 mm.; wing 14 mm.; setae 18 mm. 



Quite similar to male, except that abdomen is considerably darker. 

 Nymph: 



Measurements: Body 12-14 mm.; setae 15-20; antennae 3 mm. 



Head brown, dotted with light spots ; usually 3 light areas at posterior margin 

 between eyes and 2 lateral to each eye; anterior margin well fringed with hairs. 

 A light longitudinal median line on pronotum; 2 light areas on each side and lateral 

 margin colourless; remainder of pronotum brown with small light dots. Posterior 

 J of each abdominal segment 6-10 almost black; segments 1-6 brown; the re- 

 mainder of each segment varying from light brown to greenish yellow; ventrally 

 posterior J of each of the segments 2-8 brown; 9th segment has 2 dark areas 

 laterally. Femora light brown on upper surface with a few lighter areas and covered 

 with minute spines dorsally; posterior margins fringed with hairs; proximal end 

 of tibia dark brown and its third i dark; proximal half of tarsus dark. Setse well 

 fringed with hairs at the joints. 



While on a canoe trip up the Go Home River, June 16th, I collected a number 

 of the nymphs of this species just below Sandy Gray Falls. The only ima^os I 

 have are the ones reared from this collection. The dates of emergence are June 

 23rd and 24th. 



This species is close to H. verticis but lacks the dark median stripe on the 

 thorax, and does not show the slightest trace of a dash in the wing under the bulla. 



Heptagenia tripunctata Banks. 



Maleimago: (PI. XV, Fig. 1). 



Measurements: Body 9-11 mm.; wings 12-13 mm.; setse 25-35 mm,; fore- 

 legs 12-14 mm. 



Two small dots on median carina, slightly below level of antennae. Thorax 

 brown; on pronotum a dark spot at anterior margin in median line, sometimes 

 divided into two by a fine light line; two small dark spots just posterior to these; 

 an oblique dark streak on each side of pronotum; a brown stripe on coxa of foreleg 

 and extending up on side of prothorax. 



Short dark stripes at bases of fore and hind wings. Abdominal segments 1 

 to 7 paler than rest of body; segments 8-10 dark, similar to thorax; three dots 

 on dorsum of each abdominal segment at posterior margin; stigmal dots well 

 marked. Setse with alternate joints of basal half dark. Femur of fore-leg darkened 

 at both ends and with a median band. Tibia-tarsus joint dark. Yellowish in 

 apical costal space of wing and a reddish area in pterostigmatic space. 



