162 
The first gives 
0 e F - F6> f , 
whence 
0 ,e F = FfP, 
whatever he r, i.e. IIF=FH. 
The second gives 
0 e-/ F = F0 e-/ , 
whence, if h be the group of powers of d' ~ f , /<F=FA. 
When a group T contains more than 11,, and fewer than 
R p (2+R ; ,) substitutions having the signature a, we have an 
easy tactical method of constructing T upon H or upon F. 
The correction above made does not in the least degree 
affect either my method or my results, in the solution of the 
Prize-question of the Academy. 
In the list of titles at page 142 of the same abstract there 
is an accidental omission of the following, which is before me 
in my first manuscript — 
6 '2— 1 + 3q 2 ^‘j + $2‘2> 
A Paper was read by the President, entitled “Further 
Observations on the Carboniferous Permian and Triassic 
Strata of Cumberland and Dumfries,” by E. W. Binney, 
F.R.S., F.G.S. 
When in 1848 the red sandstones of the neighbourhood of 
Dumfries first came under the Author’s observation, in com- 
pany with his friend Professor Harkness, doubts came into 
his mind as to the propriety of their being classed with the 
trias, their characters and organic remains clearly indicating 
more of a permian age * Accordingly in his first paper 
published on this subject in the Society’s Mcmoirsf in 1855, 
allusion was made to these beds, and they were classed as 
* In tlio Quarterly Journal of the Oeoloyical Society for 1S51, p. 1G2, Sir 
B. I. Murchison doubted the sandstone of Dumfries being of triassic age, and 
preferred to class it ■with the permian. 
f On the Permian Deds of the North- West of England, vol. xii., p. 209, of 
the Society’s Memoirs. 
