DEPOSITS OF SCOTLAND. 393 
whose strata still occur in the order in which they were first 
laid down. We find, however, in Banff and Aberdeenshires, 
and more partially in Caithness, remains of the Cretaceous 
system, occurring in some localities in the character of re-for- 
mations. A deposit at Moreseat, near Cruden, elaborately des- 
cribed by Mr. William Ferguson, late of Glasgow, seems to be 
almost exclusively a re-formation of the Greensand; and on 
the Hill of Dudwick, near Ellon, there are vast accumulations 
of flints, in which the Rev. Mr. Longmuir of Aberdeen, who 
has carefully explored the locality, detected many of the char- 
acteristic Cretaceous fossils furnished by the chalk of England. 
I have examined beds of gravel a few miles to the south of 
Peterhead, in which there occurs merely a per centage, thougha 
not inconsiderable one, of these chalk flints; but I have been in- 
formed by our ingenious corresponding member, Mr. Peach, 
with whom I saw several of the Cretaceous organisms of the 
locality, that, had I set myself to examine in a different direc- 
tion, more to the north and west, I would have found thick 
gravel beds composed of chalk flints almost exclusively. The 
best collections yet made of the organisms of this denuded sys- 
tem, of which only the broken fragments survive, are those of 
Mr. Longmuir, representative of the Scottish Chalk, and of 
Mr. Ferguson, representative of the Scottish Greensand. Both 
are inadequately represented in my collection; and what it 
possesses I owe chiefly to the kindness of Mr. Longmuir, and 
to that of Mr. Dick, the original discoverer of the Chalk in 
Caithness, where it oocurs, however, merely in detached frag- 
ments in the boulder clay. Much need not be expected from 
the organic remains of a deposit so broken and scattered. I 
have seen in its flints, however, finer and more delicately pre- 
served specimens of a Flustra, that not a little resembles our 
existing Flustra foliacea, than any I have yet succeeded in 
detecting in those of England; and the group, however frag- 
