52 Woodward — On the Bridlington Crag. 
Mr. Gunn’s Essay on the Geology of Norfolk, and printed in 
‘ White’s Gazetteer’ last autumn, I adopted the Bridlington — 
species from Mr. Wood’s list with little alteration ; but having 
been requested to revise and reprint that list, I commenced 
with the shells of Bridlington, as I had the opportunity of 
examining the materials used by Mr. Wood, and more ready 
access to some of them. 
The following list has been prepared partly from a fresh 
examination of Mr. Bean’s collection, and partly from a list 
supplied by Mr. Leckenby, who has also forwarded to me at 
various times such of the fossils as I wished to examine. All 
the specimens about which I entertained any doubt have been 
kindly examined by Mr. Gwyn Jeffreys, who has enabled 
me to compare some of the critical species with their recent 
analogues. 
This investigation has led to the somewhat unexpected result 
that the Bridlington deposit can no longer be considered the 
exact equivalent of the Norwich Crag in age, or in climatal 
conditions. Of the sixty-three shells found by Mr. Leckenby 
and Mr. Bean at Bridlington, only thirty-five are common to the 
Norwich Crag. And while twenty-nine species—or one-half 
of those from Bridlington which are still living—are limited to 
the seas north of Britain, only one-sixth part of those found 
in the Norwich Crag have an Arctic character. 
In order to compare the Bridlington Shells with those of the 
Northern Drift, I have prepared a list of one hundred and 
thirty-four species, chiefly from the Clyde Beds, and belonging 
to the close of the ‘Glacial period.”* Of these only forty-two are 
common to Bridlington, a resemblance scarcely exceeding that 
of the Norwich Crag; while only twenty-nine of the Clyde 
Shells are Arctic, a proportion nearly the same as in the last- 
mentioned deposit. It follows that the Bridlington Shells are 
almost equally distinct from those of the last Pre-glacial and 
the first Post-glacial deposits, and is much more Arctic than 
either, as if formed during the climax of the last great age of 
cold in Britain.t 
* The list by Mr. James Smith of Jordan Hill was not sent to me until it was in 
type, and although I did as much to it as was possible under the circumstances, 
it still retains many inaccuracies and obscurities. 
{ The shells found by the Rey. T. Brown at Elie, in Forfarshire, include five 
sorts not hitherto met with in the Clyde deposits. Nearly half these Elie ghells 
are Arctic species. 
