The summer of 1933 was spent by Mr. W. J. Brown of the Dominion Entomological Branch in insect faunal survey work on the Gaspe Peninsula, his camp being located on the slopes of Mt. Lyall, near the headwaters of the Cascapedia river, at an altitude of about 1500 ft. A small but very interesting collection of Ephemeroptera was secured, comprising Blasturus nebulosus Wlk., Leptophlebia adoptiva McD., Leptophlebia debilis Wlk., Ephemerella aurivillii Bngsstn., Baetis vagans McD., Iron pleuralis Banks and Iron gracilis Morg. There were further three undescribed species taken which very clearly link up the Ephemerid species of the Gaspe peninsula with those of the Rocky Mountain region; of one of these the nymphal association was discovered. I describe these species as follows.