On the 18th of June, 1904, while collecting dragon-fly nymphs in Grenadier Pond, Toronto, I found two Gomphus exuviæ resting on the surface of a thick growth of algæ a few feet from the edge of the pond. I examined the debris and black swamp mud from the bottom, just below, the spot where the skins were taken, and found one nymph about two-thirds grown, apparently of the same species. On June 20th I found another exuvia on a similar part of the shore, and on examining the bottom I found several half-grown nymphs and one full-grown one, which was crawling along the surface of the algæ, evidently ready to transform. In the evening a male Gomphus furcifer emerged.