470 
Geolofju of Norfolk. 
Mr. Rose still iiialntains tlie opinion advanced in his paper, that 
the Nar clay is not any where covered by deposits containing blocks 
transported from a distance. When, however, I was explaining to 
him my views of a threefold division of the erratic block group into 
lower and upper drift and warp of the drift, he informed me that 
since his paper was published, he had found several sections in 
uhich the Nar clay was covered by what, perhaps, might be the 
warp, though, for reasons which I have already stated, he objected 
to the term as inappropriate. I visited most of the sections 
indicated h\ him, and found them, as far as I could judge in the 
unfavourable state of the pits at that season of the year, to be as 
he described them. They are, 1, the brickfield at East ^Vinch, 
where the Nar clay with fossils is covered by 7 feet of red gravel 
and gravelly clay, containing large unabraded flints ; 2, Pentney 
Warren and Narford, where the angular fragments of flint are 
smaller; 3, a spot near Bilney Church, where 4 or 5 feet of a 
deposit to which he admits the term warp to be applicable, cover 
peat, which lies immediately upon the Nar clay with its charac- 
teristic marine shells. 
The fresh -water deposit at Gaytonthorpe I shall show 
presently not only to be covered by the warp of the drift, but to 
have suffered partial denudation from it. 
The shells found in the Nar clay are all of existing species 
now inhabiting the British seas, though they differ from those 
found in the marine silt of the adjoining marshes, which are the 
group still living in the existing estuary. They are accompanied, 
in some of the pits, by broken bones and teeth of the horse, 
elephant, and rhinoceros. If these were not w ashed out of some 
older deposits, and if the place in the erratic block series which I 
assign to the Nar cla>' be correct, it would appear that in England 
the rhinoceros and elephant w ere not entirely destroyed by the 
submergence which produced the till and upper drift. Mr. Lyell 
has shown that in America the mastodon flourished after the 
erratic block period. The great fossil deer of Ireland appears to 
have inhabited the British Isles both before and after that epoch. 
The auroch, or bison (Bison p7-{sci(s of Owen), which was con- 
temporary with the extinct mastodon, entombed in the Norwich 
crag and other tertiary beds of older date, has survived all these 
revolutions, and is still living in Lithuania, where it is preserved 
in one of the Royal or Imperial forests like our wild cattle of 
Chillingham Park.* 
The Nar clay, though it has been penetrated to the depth of 
40 feet, has not been sunk through. The proof of its super- 
* See INIurchison's 'Geology of Russia,' and Owen's 'British Fossil 
Mammalia.' 
