S300 Correspondence—Prof. E. Hull. 
the attention of the writer to the evidence of submersion as afforded 
by the existence of the high-level shelly gravels of North Wales and 
Derbyshire, together with the existence of rolled quartz-pebbles 
scattered over the Cottswold Hills of Gloucestershire, formed of 
Jurassic limestones, up to 600 feet above sea-level ; a fact corroborated 
by Professor J. Phillips in his “‘Geology of Oxford.’ With this 
preface I proceed to give Prestwich’s letter :— 
“25th July, 1895. 
““My pEarR Huiit,— 
Thanks for your letter. 1 quite agree with you as to the important 
submergence in Glacial times, which has left such clear evidence on the 
Cotteswold Hills and Welsh Mountains. It is surprising to me that the ice- 
ploughing hypothesis could ever be sustained. Some half-century ago it 
was my good fortune to come across one of the fossiliferous gravels in the 
hills (1100 feet) between Chesterfield and Buxton. Why the old simple 
explanation should ever have been pushed on one side in favour of the more 
fanciful view I cannot understand, ie it be the innate love of change. 
66 am, 
Very truly yours, 
JosEPH PRESTWICH.’’ 
The shelly gravels of Moel Tryfaen, discovered by Trimmer many 
years since, are well known, having been often described; but those 
described by Nicholson as occurring at nearly the same level on the 
Denbighshire Hills (from 1070 to 1170 feet) have not been so 
generally recognised, and yet are important as indicating the level of 
submergence over a wide area. The beds occur on the ridge of Mill- 
stone Grit of Gloppa, near Oswestry. They are 60 feet in thickness, 
stratified, and contain numerous marine shells, of which some are 
living in the Irish Sea and are also found in the Moel Tryfaen beds 
(Q.J.G.S., vol. xlviii, p. 86). 
Before concluding, it may be well in this connection to refer to the 
important paper by Mr. W. Shone on the ‘‘ Glacial Deposits of West 
Cheshire”’ (Q.J.G.S., vol. xxxiv, p. 383), describing in detail the three 
divisions of the Drift Series as they are found in Lancashire and 
Cheshire, and the abundant marine fauna of the Upper Boulder-clay 
and Middle Sands as they occur near Newton Hollows in West 
Cheshire, both being underlain by the Lower Boulder-clay. The 
Upper Boulder-clay is stated to have yielded 57 species and varieties 
of Mollusca, 2 Polyzoa, 26 Ostracoda, 3 Echini, and the Middle 
Sands contain 2 species of Cardium, also Tellina baltica and Turri- 
tella terebra; from the Lower Boulder Drift shells were absent, but 
erratic blocks numerous, offering a remarkable contrast to the over- 
laying marine beds.' Those who, with Mr. Lamplugh, refuse to 
recognise an Interglacial (as well as Upper Glacial) marine stage of 
the Drift Series, are invited to read Mr. Shone’s very instructive 
paper, which may be considered as descriptive of the Drift deposits 
as they occur generally throughout the north-west of England. 
Epwarp Hott. 
14, Srantey Garprens, Norrine Hitt, W. 
May 20th, 1907. 
1 See also Mr. R. D. Darbishire’s paper on the shells from the Macclesfield 
Drift-beds: Got. Mac., 1865, pp. 293-299, with a folding-table giving a list 
of 58 species found there. 
