864 ON TERTIARY FORMATIONS OF THE ALPS, NORTH ITALY. 
north, whence all the moraine débris has travelled. Iam inclined 
to think it 1s 7m situ, because on removing as much as I could of the 
sand and stones I did not reach the bottom of the mass; also 
because the present level of the bottom of the ravine, as well as 
that of the plateau in front, may be assumed to be due to the im- 
permeable nature of this clay, of which a small portion only is now 
exposed to view. 
I have thought the presence of this fossiliferous clay worth re- 
cording, as it may be still more exposed in another year or two 
here or in some of the adjacent ravines, and others may be led to 
visit and examine the section*. 
* The fossils are mostly casts of Mollusca, Echinoderms, &c.; but the marl 
is full of organisms of various kinds, which I hope to get examined. 
