214 The Ottawa Naturalist. [March 



Lake Temiscaming, the level of which at high water is five 

 hundred and ninety-six feet above the sea. Perhaps the most 

 remarkable thing about this clay is the scarcity of marine shells 

 even where it is known to be far below the level reached by the 

 sea during the Champlain subsidence. Marine fossils are 

 recorded at Montreal at a height of five hundred and sixty feet, 

 at Smith's Falls four hundred and twenty feet, near Galetta four 

 hundred and seventy-five and Chelsea four hundred and twenty- 

 five, so that the land in this valley during the time 

 the Leda clay was laid down must have been six hundred 

 feet lower than at present. We can therefore, I think, 

 fairly assume that the stratified clays which are not 

 more than five hundred or six hundred feet above sea 

 level are marine. The marked resemblance of the clays on 

 the higher levels to those on the lower, where fossils are found, 

 is strong corroborative evidence of a similar origin. Even at 

 the lower levels fossils are by no means common in this clay. 

 In the city of Ottawa where excavations are frequently made 

 and large quantities of clay are throwu out, I have seen fossils 

 in two places only. At Mohr's Corners, about a mile from the 

 village of Galetta, there is a sand terrace abounding in marine 

 .shells. Underlying the sand there is a bed of this 

 clay, well stratified, twenty to thirty feet deep, and al_ 

 though there was a section ten feet deep on the roadside for a 

 quarter of a mile, a careful examination revealed no fossils. Sir 

 J. W. Dawson says : " Where the Leda clay is thick and well 

 developed it admits of sub-division into a lower Leda clay, un- 

 fossiliferous or with only shells of Leda glacialis and Maconia 

 Grcenlandica, and an upper Leda clay, usually more sandy and 

 holding a rich boreal fauna identical with that of the northern 

 part of the Gulf of St. Lawrence at present."* Mr. F. B. Taylor in 

 a recent article says " Near the city of Ottawa the upper limit 



* Canadian Ice Age, p. 60. 



