R. NM. Deeley—Glacial Deposits in the Midlands, ete. 158 
longitudinal nerves being prominent, one might even be tempted, in 
determining this fossil, to consider the Graminee also. But the 
firm texture and the quality of the epidermis of the leaf do not 
admit of such a view. 
I have named the species Ceratozamia Hoffmanni. The fossil leaf 
above described will be figured in my Memoir on the Tertiary Flora 
of Leoben. 
TV.—Correnation oF tHE LinconnsHirE PuerstoceNe Deposits 
* WITH THOSE oF THE Mip1LAND CouNTIES. 
By R. M. Drsxey, Esq. 
HE Memoir of the Geological Survey on ‘“‘ The Geology of Part 
of Hast Lincolnshire,” by A. J. Jukes-Browne, lately reviewed 
in the Grotoetcat Magazine, proves so interesting that I am tempted 
to compare the classification of the Glacial deposits which he has 
adopted with that I have proposed for the Midland Counties. There 
are also some features in the distribution and lithological characters 
of the Boulder Clays to which I should like to draw attention. 
At the outset Mr. Jukes-Browne shows that there are in Lincoln- 
shire two types of Boulder Clay occupying areas separated from each 
other by the Chalk Wolds. These two deposits, which he regards 
as having been formed at different stages of the Pleistocene period, 
are described as the “Older” and the “‘ Newer Boulder Clay.” The 
Older Boulder Clay, the Chalky Boulder Clay of Mr. Searles Wood, 
an intensely chalky deposit, is only found on the west side of Sheet 
84 of the Ordnance Survey. The Newer deposits are brown or 
purple clays, which rise up from beneath the alluvium stretching 
along the coast. Both these deposits contain intercalated beds of 
sand or gravel. In a paper printed in the Quart. Journ. Geological 
Soc. vol. xli. p. 114, Mr. Jukes-Browne shows that the brown or 
purple clays, generally known as the Hessle and Purple Clays, 
frequently occupy interglacial valleys cut through the older Chalky 
Boulder Clay. In my own paper I found it most convenient to 
divide the Pleistocene period into three epochs, namely, Older, 
Middle, and Newer Pleistocene, the Great Chalky Boulder Clay 
and associated chalky gravels being relegated to the Middle Pleisto- 
cene division, an arrangement which might also be adopted for 
the similar deposits of Lincolnshire. As far as I am aware the 
only Older Pleistocene deposit in this county is the mass of 
Quartzose Sand on the hill near Gelston, north of Grantham. A 
careful search would doubtless reveal many other sections both of 
Boulder Clay and gravel. Too much reliance must not be placed on 
the colour of a deposit. Similarity of colour no doubt indicates that 
the materials forming the different deposits have been derived from 
similar rocks, but we must not be too ready to assume that it also 
indicates similarity of age. In the Midland Counties the adoption 
of such a test would lead to great confusion, for in this area the 
Older and Newer Pleistocene clays, having been generally formed by 
the breaking up of similar rocks, are somewhat similar in colour, 
