GEORGIAN BAY EPHEMERIDM 139 



SESSIONAL PAPER No. 39b 



Nym'ph: 



Measurements: Body 9-10 mm.; setae 10 mm. 



Head dark brown, dotted with minute light spots. Pronotum similar in colour 

 to head; two light areas on each side, the- outer one sometimes joined to the light 

 margin. Abdomen dark brown with a granular appearance; sometimes a faint 

 broad, dark longitudinal streak can be made out with 2 dots on each side of it 

 on each segment excepting 9 and 10; ventral surface lighter with a median row 

 of irregular dark spots and lateral rows of small dots or lines, the median dots 

 sometimes broken up so that only 4 or 5 small dots remain in their place. On seg- 

 ment 9 the markings are usually jointed, forming roughly three sides of a square. 

 Femora with 4 irregular dark bands; both posterior and anterior margins very 

 hairy. Claws pectinated. A very hairy species, having anterior margin of head, 

 sides of thorax and abdomen very hairy. 



This nymph was first taken on June 15 in what is commonly called the Narrows, 

 near the mouth of the Go Home River. The water here had a well-marked current, 

 but scarcely swift. On June 30 I found them very numerous in the very swift 

 water of a rapid near the mouth of the Musquash River. Nearly a month after 

 this on July 20 and 22 I discovered mature nymphs at an old lumber chute on the 

 Go Home River in fairly swift water. 



Imagos were bred from the nymphs taken at the Narrows on June 22nd and 

 25th; at the Musquash rapids from July 3 to 5th; at the chutes July 24-29th. 

 No imagos were captured. 



Heptagenia luridipennis Burm. 



,^ , . (PI. XV. Fig. 3). 



Male imago: 



Measurements : Body 7-8 mm. ; wings 8 mm. ; setae 2 -22 mm. ; fore-leg 8 mm * 



Face clear; slight dark marks at posterior margin of head between eyes. 



Median longitudinal stripe on pronotum; sides brown; mesonotum dark brown; 



brown area in front of base of middle leg. Segments 1-7 of abdomen light coloured 



segments 8-9 and 10 dark, similar to thorax, narrow black bands along posterior 



margins of the segments; stigmal dots distinct. Apical costal area of wing not 



distinctly darkened and no reddish coloured area. 



Female imago: 



Measurements: Body 9 mm.; wings 10 mm. 



Nymiph: 



Measurements: Body 7-8-5 mm.; setae 10-14 mm. 



Head brown with light dots; anterior margin fringed with hairs. Prothorax 

 similar in colour to head; on pronotum a light spot on each side of median line; 

 lateral to this another larger one and lateral to this again another which extends 

 to the lateral margin. Abdomen similar in colour to prothorax; a row of black 

 dots on each side corresponding to the stigmal dots of imago; segment 3 for the 

 most part light with a round brown spot in median line and with two short pro- 

 jections laterally; segment 4 with a small triangular brown spot in median line 



