The recent finding of fresh water shells in Iroquois beach gravels close to Toronto appears to settle the long debated question as to whether the Iroquois water was a fresh water lake or an arm of the sea, and is per‐ haps of sufficient importance to justify a brief redescription of the whole series of lake deposits in the neighborhood. This must be the only excuse for adding to the already voluminous literature on the Iroquois beach and the complicated problems with which it is connected.
Although Dr Spencer long ago followed and determined the elevation of the Iroquois beach north of lake Ontario, as Dr Gilbert has done on the south, it seemed worth while to make a more careful survey of the old coastline in the neighborhood of Toronto, and the results of this are given in the accompanying map (figure 1), malting it . . .