216 THE ICE AGE IN CANADA. 



pocket lens, and are usually in as fine preservation as 

 recent specimens, especially in the deeper and more 

 tenacious layers of the Leda clay. They are, however, 

 usually more abundant in the somewhat arenaceous layers 

 near the top of the Leda clay, and immediately below the 

 Saxicava sand, and especially where this layer contains 

 abundance of shells of mollusca. I have nowhere found 

 them more abundant or in greater variety than at the 

 Glen brick-work near Montreal, on the McGill College 

 grounds, and at Logan's Farm. At the Glen brick-work 

 a few worn specimens of Polystomella are contained in 

 the beds underlying the Leda clay and equivalent to the 

 boulder-clay, which, however, has in general, in the vicinity 

 of Montreal, as yet afforded no marine fossils. 



In searching for Foraminifera in the clays of Rlviere- 

 du-Loup, I have observed in the finer washings several 

 species of Diatomaceae; and among these a species of 

 Coscinodiscus very frequent in the deeper parts of the 

 gulf of St. Lawrence. But on the whole diatoms appear 

 to be rare in these deposits. In the Eiviere-du-Loup 

 clays I have also observed the pollen grains of firs and 

 spruces. 



The nomenclature used above is that of Parker and 

 Jones, in their paper on the North Atlantic Soundings, in 

 the Transactions of the Eoyal Society. For figures of the 

 species, I may refer to that memoir, and to my previous 

 papers published in the Canadian Naturalist. 



(2) Porifera. 

 Tethea Loyani. Dawson. 



Leda clay, Montreal. This species has not yet been recognized in a 

 living state. Its spicules in considerable masses, looking like white 

 fibres, are not uncommon in the Pleistocene at Montreal. 



