THE CANADIAN ENTOMOLOGIST. 331 



margins of lateral ones not fringed. Femora stout and flattened, 

 brown in colour, lighter at distal and proximal ends, and two or 

 three irregular light areas toward middle; covered with minute 

 spines and fringed along posterior margin with hairs. Tibiae al- 

 ternately light and dark banded; fringed along both anterior and 

 posterior margins. Tarsi brown, with proximal tips colourless. 

 Ungues double on each leg, the large one well covered, the other 

 small and lateral to the large one. 



Subfamily — EphemerincB. 



Hexagenia hilineata Say. 



This was a very common species at Go-Home Bay. The 

 nymphs were first taken on June 6th, by dredging in water 15 to 

 45 feet deep. The bottom was very muddy. When the nymphs 

 were placed in jars containing about 4 inches of mud, they imme- 

 diately began to burrow, and were able to bury themselves in a 

 very short time. At first the gills were left partly exposed, and the 

 position of the nymphs could be detected by the waving motion 

 in the thin mud. Later on they completely buried themselves, 

 and only the round openings of the burrows could be seen. The 

 first of these nymphs to emerge was on July 3rd, and others fol- 

 lowed in July and August, while one was still alive in the breeding 

 jar on September 9th, when the Station was closed. On June 13th 

 the first subimago was captured at large, but not till June 28th 

 did imagos appear in large numbers. They would commence their 

 flight shortly after sunset, flying in large swarms about the tree 

 tops. The hum of their wings could be heard up to a distance of 

 125 feet or more. The females deposited their eggs by flying up 

 and down the shore, brushing off the eggs as they appeared in two 

 small, rather compact columns from the openings of the oviducts, 

 by dipping to the surface of the water. On July r2th a. female was 

 caught just after copulation, and she deposited a large number of 

 eggs by being held by the wings and touching her abdomen fre- 

 quently to some water in a jar. These eggs hatched in thirty-six 

 days. 



Nymph: (PI. VI, fig. 1.) 



Measurements — Body 30-35 mm.; set^ 13-15 mm.; antennae 

 5-6 mm. Head rather yellowish, with dorsal surface between 



