LIFE HISTORY NOTES ON EPHORON, POTAMANTHUS, LEPTOPHLEBIA AND BLASTURUS WITH DESCRIPTIONS (EPHEMEROPTERA)

Abstract

In June 1932 a very immature nymph of Ephoron leukon Will was found in the Credit R. near Erindale, Ontario. In 1934 full grown nymphs of this same species were found in great numbers in the same locality after their hiding place was once located. They are burrowing nymphs which inhabit a tubular burrow associated with stones in the rapids. Loose stones. when turned over revealed no nymphs and lackcd the marks of the tubes on them. Stones, however, which were partly imbedded in fine grey silt (originating from the breakdown of shales in the vicinity) when turned over- revealed nymphs clinging on the sides and bottom in the remnants of the tubes. Curiously enough the time of day at which col1ecting was done was important.