140 MARINE AND FISHERIES 



5 GEORGE v., A. 1915 



with base to anterior margin while the apex meets a large brown area leaving a 

 small light area on each side of the triangle; lateral to the brown area is a light 

 one and lateral to this is a triangular dark spot in the posterior angle of the seg- 

 ment; segment 5 much like the 4th; segment 6 entirely dark except for two small 

 spots at anterior margin and 2 toward lateral margin; segment 7 with a triangular 

 dark spot in median line with base to anterior margin and apex reaching about 

 middle of segment; on each side of triangle 2 dark spots; segment 8 similar to 

 the 6th; segment 9 irregularly marked; roughly, it is dark with a darker median 

 longitudinal stripe, 2 light spots on each side and another at lateral margin; seg- 

 ment 10 entirely dark; ventrally 2 dark spots at lateral margins of 9th segmeiiT; 

 just beside the lateral spines of that segment; sometimes a triangular spot in the 

 median line. Setse with basal half fringed with hairs at joints. 



The nymphs of this species were the last to be taken. On August 23rd I found 

 them in a rapid just above Sandy' Gray Falls, about 5 miles from Station Island. 

 I was successful in rearing quite a number of these dating from August 28th to 

 Sept. 1. 



Heptagenia canadensis Walker. 



, . . . (PI. XVI, Fig. 4). 



Male imago: 



Measurements : Body 8-9 mm. ; wings 9 mm. ; setae 20-22 mm. ; foreleg 9 mm. 



A dark species; a black band on face below each antenna; dark reddish brown 

 between lateral ocelli; a small black dot close to inner margin of each eye; posterior 

 margin of head with a narrow black line thickened at median line. Prothorax 

 brown; short dark band along posterior margin of pronotum, the ends of which 

 turn obliquely across the side of pronotum. Mesothorax rich brown dorsally, sides 

 lighter, oblique dark stripes at base of fore and hind limbs; dorsum of abdomen 

 black; slightly darker in median line; and a lighter area in each segment on either 

 side of it. Posterior margins of segment 1-9 margined with black; 10th segment 

 lighter; stigmal dots obscured by the black colour of the abdomen; penis lobes 

 rather oblong in shape; setae almost white, tinged with black; joints darker. 

 Femur of fore-leg almost yellowish tinged with black and having median and distal 

 black bands. Tibia lighter; tibiotarsal joint black; tarsi tinged with black; 

 lengths of segments arranged in increasing order 5, 1, 4, 3, 2; the 2nd slightly 

 longer than the 3rd. Wings with a dark dash and numerous cross-veins margined 

 with black between the dash and base of wing; terminal margin of hind wing 

 slightly tinged with black. 



Female imxigo: 



Measurements: Body 9-10 mm.; wing 12 mm.; setae 15 mm. 

 Abdomen very reddish, often blackish red. 



Nym-ph: 



Measurements: Body 11 mm.; setse 15 mm.; antennae 3 • 5 mm. 



Head reddish brown in colour; a small dark area immediately in front of each 

 antenna; and another about the same size in front of each eye; a black dot behind 

 each lateral ocellus; a light area in front of median ocellus, and a larger light area 



