476 
Correspondence — Rev. T. G. Bonney. 
THE CORAL RAG OF TTPWARE. 
Sir, — In Messrs. Blake and Hudleston’s admirable paper on the 
Corallian Bocks in England, “ the well-known though very inacces- 
sible exposure of Corallian beds at Upware ” does not appear to 
liave received from the authors such careful study as those in otber 
localities. They state tliat in the northern quarry tlie beds “ dip to 
the south, or in an opposite direction to those of the Rag-pit, so that 
there is a synclinal in which are found the Neocomian sands,” and 
they give a “ presumed section,” in which the said sands are repre- 
serited as so situated. Now this section is not confirmed by any 
evidence known to me. The dip in the northern pit — so far as 
there is any dip at all — is northward, not southward, probably a 
little west of north. I verified this a few days since in the Company 
of three friends, all fairly accustomed to geological Observation. 
Further, any one who has watched the working of the ‘ coprolite ’ 
poits, knows that the Neocomian beds rest unconformably on the 
Coral Bag, and thin out against the side of the ridge. The road 
along its crest (if one may use the word), between the two pits, 
nowliere crosses Neocomian beds. Two small shallow pits have 
indeed been opened adjoining the road on the west side, a little less 
than a quarter and half a mile respectively south of the northern pit. 
These seemed to be still in the same rock as it ; and thus in all 
respects are unfavourable to the theory of a synclinal. The position 
of the strata was given some years since by Mr. Keeping in this 
Magazine (Yol. Y. p. 272), and I have since examined several 
sections confirming this one, with the exception that I have never 
myself seen the Kimmeridge Clay exposed. Again, at the present time 
there is a considerable patch of the base of the Gault laid bare, just 
west of the south end of the Rag-pit, and perhaps four yards below 
the crest of the limestone ; that is, exactly where it should not be on 
any theory of a synclinal. The stratigraphy is puzzling enougli ; 
but, so far as the evidence goes, it appears to me rather in favour of 
the old theory of an anticlinal as represented by Fitton (Trans. G-eol. 
Soc., vol. iv. pl. xi.). The present authors may be right in assign- 
ing to the rock of the northern pit a lower horizon than that of the 
Southern ; but I have no hesitation in saying that the evidence at 
present is only palaäontological, and this is not strong. 
The otber matter is a personal one, and refers to their mention of 
my own account of this district. I am well aware that in my 
Geology of Cambridgeshire it was “partially, but not very fulljq 
described,” because the book only professes to be a sketch for the 
use of students. At the same time, when authors call attention to 
an imperfection, one may fairly expect that they will considerably 
augment our stock of knowledge. I venture to assert that the 
questionable Statement, discussed above is the only material addition 
contained in the paper on the Corallian rocks. The two accounts 
are about equal in length, and contain as nearly as possible the same 
facts. Again, the authors’ statement about the position which I 
