THE 
LONDON AND EDINBURGH 
PHILOSOPHICAL MAGAZINE 
AND 
JOURNAL OF SCIENCE. 
^ 
[THIRD SERIES.] 
MARCH 1840. 
XXX. On the true Order of Succession of the Older Stratified 
RocJcs in the Neighboiu'hood of Killarneij and. to the North of 
Dublin. By Richard Griffith, Esq.., F.G.S. L., and 
President of the Geological Society of Dublin, 
[See Section Plate II. and Plan PI. III.] 
To the Editors of the Philosophical Magazine and Journal, 
Gentlemen, 
'T^HE Geological map of Ireland, which presents an epi- 
tome of my geological labours in the field, continued 
at intervals for upwards of thirty years, is now before the 
public, and has in fact become their property. Though I 
do not venture to assert that all the lines representing rock 
boundaries which it contains are perfectly correct, still I will 
say that none have been laid down without consideration. 
Much detail no doubt still requires to be worked out within 
the great divisions, particularly in the carboniferous lime- 
stone series, and many of the smaller greenstone protrusions 
have yet to be pointed out; but I am fully of opinion that 
the great lines nearly represent the true boundaries of the 
several rock formations, according to the order of superposi- 
tion indicated by the table of geological colours. Having this 
impression on my mind, I confess I was somewhat startled by 
observing in the Number of the Philosophical Magazine for 
December last, (vol. xv. p. 442.) a paper communicated by my 
friend Mr. Charles William Hamilton of Dublin, which con- 
tains statements, some of which are illustrated by sections, re- 
lative to the geological positions of the strata of several parts 
of Ireland, quite at variance with those assigned by me to the 
same rocks in the geological map. This paper also asserts 
that I have indicated the occurrence of rocks in certain places 
in which no such rocks are to be found. These are charges 
Phil, Mag, S. 3. Vol. 16. No. 102. March 1340, M 
