Oorrespondence—Mr. G. H. Kinahan. 300 
bottom, as he does, but neither in respect to them, or to very much 
more of the facts connected with the North Norfolk Cliff (inclusive 
of the true Forest-bed), can I admit Mr. C. Reid’s memoir to be any 
authority whatever, regarding it, as I do, as greatly at variance with 
the real state of the case. : 
As to tracing the masses in the Contorted Drift in a train up to 
Lincolnshire, which Mr. Reade challenges me to do, the formation 
containing them has been destroyed over West and North-west 
Norfolk, and over the area between there and the Lincolnshire 
Wold, by the subsequent advance of the Land-ice giving rise to the 
Chalky clay, as delineated in the maps to my late memoir on the 
Newer Pliocene period in England, but as far as the Contorted Drift 
can be distinguished in that direction they occur. 
June 16th, 1883. SEARLES V. Woop. 
WEST GALWAY ROCKS. 
Str,—These rocks are referred to at page 657 of the “'Text Book 
of Geology,” by Dr. A. Geikie, and it is stated that my classification 
suggests that the Upper Cambrians pass unconformably mto the 
Llandeilo formation without the occurrence of the thick Arenig rocks 
of Wales. I presume that my opinions have not been made sufficiently 
plain, as this eminent geologist has evidently misunderstood my 
writings on the subject. In the “ Geology of Iveland” the classifica- 
tion of Lyell, and which also appeared to be the opinion of Sir A. C. 
Ramsay, was followed,—the representatives of the Arenig rocks of 
Wales being included in the Cambrian group, among the Upper 
Cambrians. But as some of my reviewers suggested that I had ~ 
ignored the Arenig series, in subsequent writings more details were 
entered into; as, for instance, in the papers on Irish Paleozoic Rocks, 
Manchester Geol. Soc. April. 1879; Supposed Upper Cambrian Rocks, 
Counties Tyrone and Mayo, Royal Irish Academy, December, 1879 ; 
On the Thickness of the Irish Bedded Rocks, Royal Dublin Society 
and Royal Geol. Soc. Ireland, November, 1880, etc., etc. In these 
and other papers published about that time, the supposed equivalents 
of the Welsh Arenig rocks are specially mentioned, and the reasons 
given for supposing them to be equivalents. 
How the rocks in the south portion of West Galway can be older 
than those in the north portion, it is hard to conceive when we know 
that the former are in part made up of fragments of the latter; that 
is, the rocks which are said to be oldest are made up of the débris 
of the younger rocks. Furthermore, on account of the remarkable 
similarity in the rocks and groups of strata that margin on the north- 
east and south, the rocks of the Bennabeola group of hills, also for 
other cognizable reasons, I am compelled to believe with Griffith , 
and all the geologists who have examined the country that the rocks 
of the Bennabeola group of hills must be older than those in the 
country to the south-east and north of them. 
In this south-west Connaught tract of Metamorphic rocks, which 
includes portions of N.W. Galway and 8.W. Mayo, there were two 
