No. 3.] DAWSON — POST-PLIOCENE. 257 



In general terms it may be stated that all the species of For- 

 aminiiera found in the Post-plloccne stiil inhabit the Gulf and 

 River St. Lawrence. Several species found in the Gulf of St. 

 Lawrence have not yet been recognized in the Post-pliocene, and 

 these arc mostly inhabitants of depths exceeding 90 fathoms, or 

 among the more southern forms found in the Gulf. 



On the whole, the assemblage, as in the northern part of the 

 Gulf of St. Lawrence at present, is essentially arctic, and not 

 indicative of very great depths. 



The sandy forms which are not uncommon in the Gulf are 

 very rare in the Post-pliocsne ; but this may be accounted for by 

 the greater difficulty of washing them out of the clay, or possibly 

 their cementing material may have decomposed, allowing them to 

 fall to pieces. As the epidermal matter of shells is often pre- 

 served, the last supposition seems less likely. The Leda clays 

 are, however usually very fine and calcareous, so that there was 

 probably more material for calcareous than for arenaceous forms. 



The Foraminifera are very generally diffused in the Postplio- 

 cenc clays, though much more abundant in some layers than in 

 others. They may easily be detected by a 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 most 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 abund- 

 ance of shells of ^lollusca. I have nowhere found them more 

 abundant or in greater variety than at the Glen Brick-work, 

 Montreal, on the McGIll College Grounds, and at Logan's 

 Farm. At the Glen Brick-work a few worn specimens of Poly^ 

 stomella 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 aff"orded no marine fossils. 



In searching for Foraminifera in the clays of Rivicrc-du-Loup, 

 I have observed in the finer washings several species of Diato- 

 mvccoe ; among these a species of Coscinodiscus very frequent in 

 the deeper parts of the Gulf of St. Law^-ence. But on the whole 

 Diatoms appear to be rare in these deposits. In the Rivicre-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 

 Vol VI, X No. 3. 



