THE CANADIAN ENTOMOLOGIST 255 



Gray Falls. The onh' imagos I ha^•e are those bred from this col- 

 lection. 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 iripunctata, Banks. 



Nymph. 



Measurements: Body, 11-14 mm.; setae, 12-16. Head deep 

 brown, occasionally almost dark dotted with light spots; three light 

 spots; three light areas along anterior margin of head and one at 

 posterior margin between eyes. Pronotum- similar in colour to 

 head, with light dots and about five larger light areas on each side; 

 lateral with a light area which extends inwards som.e distance. A 

 light area in antero-lateral angle of mesothorax. Femur stout, 

 wdth five irregular lighjt areas; small spines very numerous; posterior 

 margin fringed with hairs. Tibia with tvvo dark and two light 

 areas, arranged alternately. Abdomen similar in colour to head 

 and thorax; a light area on segments 4 and 5 containing a small tri- 

 angular dark area at anterior margin of segment 5, lateral to which 

 are two dark dots; another light area on segments 7, 8, 9 and 10 

 containing two dark dots on 8th and two on 9th segments; usually 

 three small dark dots at posterior margin of each segment. Ven- 

 trally two longitudinal rows of dark dots, increasing slightly in size 

 toward posterior end; segment 9 usually with two pairs, the an- 

 terior pair small, posterior pair larger. Setae with alternate dark 

 and light areas. Gills have the lamellae slightly rounded at distal 

 end. 



The nymphs of this species were seldom found in swift water, 

 but were everywhere abundant about Go-Home Bay, in quiet bays, 

 along open shores and in quiet streams. They could be found at 

 any time during the summer. The first bred specimens emerged 

 May 31, but the first capture was not made until June 11. On 

 this date a small swarm of about 20 individuals was discovered 

 about 8.15 p.m. flying from 10 to 20 feet high along the shore of 

 Station Island, facing north. One female and several males w'ere 

 taken. Soon after this they became very abundant and remained 

 so until about July 5th. The last bred specimen is dated Aug. 13. 



