122 
THE GEOLOGIST. 
were all on the solid till. In tlie valleys of tlie Trent and the 
Ancholme, in Lincolnsliire^ there was no till whatever upon the 
peat ; but it was found at Hornsea^ Norfolk^ and along the coast. 
The ten different species of marine shells found by Mr. Harkness^ 
at Ormskirkj would go very far to make the till a tertiary and 
not a post-tertiary formation. They occured in the clay, and 
one of them was a warm sea, like one in the Mediterranean. 
Some of them had not been found near Manchester, neither in 
the till or in No. 3. Mr. Gooch said, he had never seen any in 
the till. 
January 26thj 1843. — J. Hey wood, Esq., President, in the 
chair. 
A paper was read, entitled, " Remarks on some parts of Prof. 
Agassiz's Glacial Theory,^' by Mr. Robert Harkness. 
" M. Agassiz has, in an essay published is the Edinbui'gh 
New Philosophical Journal, for October 1842, detailed in a very 
lucid manner his observations on the applicability of the glacial 
theory, and some very important phenomena, which he has ob- 
served on the Mer de Glace, during his abode last year on the 
glacier of the Aar. In the paper referred to, he treats of the 
erratic phenomenon as it occurs in Great Britain, under three 
categories : — 1st, The phenomena proper to the interior of val- 
leys; 2nd, the dispersion of erratic blocks in plains, at great 
distances from their origin ; and 3rd, parallel terraces. It is to 
the 2nd, or the dispersion of erratic blocks in plains, at great 
distances from their origin, to which I shall at present refer, 
and endeavour to show that one of the deductions in that part 
of the essay is not legitimate. In this portion of the essay 
Agassiz commences by mentioning the generality of the occur- 
rence of the erratic deposit ; after which he details, in a general 
manner, the nature of the deposit ; he then considers the inca- 
pability of cuiTcnts to convey masses of rock from their present 
source. The action of glaciers is then discussed, and a descrip- 
tion of what takes place during their motion is then given. 
