THE LOWER CARBONIFEROUS BEDS OF HOOK. 
153 
found in it, nor ~so far as I am aware, in any other part of 
Ireland. 
Too much importance has been attached to systems and system- 
makers hitherto in Geology; and many of the controversies waged, 
respecting Silurian and Devonian groups, have had their origin, or, 
at least, owe their continuance, to a desire on the part of the contro¬ 
versialists to extend, beyond their due boundaries, merely local sub¬ 
divisions and names. The group of rocks described in this notice 
is a continuous whole, and should be viewed as such. The plant 
beds, on which the difficulty of classification has principally turned, 
ought, in my opinion, to be classed with the Carboniferous system, 
as they contain forms of plants, such as Knorria, which are recog¬ 
nised in Germany and elsewhere as eminently characteristic of Car¬ 
boniferous beds. 
I have already pointed out what I conceive to be the relative 
positions of the Limestone groups, and the lower Limestone subdivi¬ 
sions of Kilkenny. I now append a Tabular View showing this re¬ 
lation ; and add, in another column, the corresponding beds described 
by me as the lower Carboniferous beds of the Menai Straits:— 
Comparative View of Lower Garboniferous RocJcs in Wexford , 
Kilkenny , and Carnarvon. 
Wexford. 
Kilkenny. 
Carnarvon. 
l- Old Red Sandstone. 
Conglomerates alterna¬ 
ting with red sand¬ 
stones, .1150 
2. Yellow Sandstone. 
Alternating beds of red 
and white, or yellow 
sandstones, with red 
conglomerate,.... 382 
Lower Limestone. 
3. Lower Division. 
Arenaceous in lower 
beds, and shale part¬ 
ings in upper beds, . 851 
4. Dolomite. 
Gray, splintery, and 
coarsely crystalline, 
dividing into rhombic 
fragments.385 
Lower Limestone. 
1. Lower shales, alterna¬ 
ting with sandstones, 450 
2. Dark gray limestone, 
with shale beds and 
partings,.650 
3. Lower Dolomite, , . 200 
1. Yellow sandstone 
with plant remains, 
alternating with crys¬ 
talline limestone and 
red shale,.204 
2. Nodular red and 
calpy brown lime¬ 
stones, highly fossi- 
liferous,.390 
VOL. VII. 
Q 
