PROCEEDINGS 
ROYAL PHYSICAL SOOIETY. 
SESSION CXXEIT. 
Wednesday, 15th November 1893.—RopErt Kipston, F.R.S.E., 
F.G.S., retiring Vice-President, in the Chair. 
The retiring Vice-President delivered the following opening 
address, “On the Various Divisions of British Carboniferous 
Rocks as determined by their Fossil Flora ” :— 
GENTLEMEN,—The study of Paleontology naturally suggests 
three lines of investigation—tIst, the vertical and horizontal 
distribution of the organisms, or their distribution in time 
and space; 2nd, their affinities with recent and other extinct 
forms; and 3rd, the part fossils play in affording data for 
the identification of strata which may be widely separated 
in space. 
On the third of these heads, especially in regard to British 
Carboniferous rocks, I wish to make a few remarks this evening. 
This subject is neither new nor free from differences of 
opinion, especially in regard to the value of fossils in 
determining or correlating strata. The Mollusca have 
usually been selected as the most suitable. organisms for this 
purpose—chiefly on account of their wide distribution, their 
great numbers, and the generally good condition in which 
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