Physical Geology of the Dingle and Iveragh Promontories. 598 
Is it not also possible, as Professor Mellville used to argue, that 
within the latter part of the Dingle-Glengariff period, at one 
locality (Dingle), disturbance, denudation, and discordant deposi- 
tion, ranging up into the Lower Carboniferous (Old Red) period 
had taken place, while thirty-six or forty miles away (or more) this 
disturbance was non-existent, and continuous deposition from 
the lower to the upper stage was in progress? This point must 
affect the question until further positive evidence of the discord- 
ance in Iveragh is adduced. 
3. Supposing this discordance incapable of demonstration, even 
then it does not seem to me, if complete conformity between the 
Silurian and the Dingle beds is proved by alternation, there need 
be any difficulty in adopting Professor Hull’s view, that the 
Dingle-Glengariff beds are more connected with the Silurian than 
with the Old Red Sandstone horizon of the Carboniferous period. 
In adopting this view the carboniterous aspect of the Glengariff 
beds’ plants should be allowed to partake of the uncertainty 
which seems to cling to deductions based on palzeobotany alone. 
But if there be any ordinary appearances of transition between 
the Carboniferous slates and Yellow Sandstone and the Dingle- 
Glengariff series, then the plants of the latter would have a local 
value in establishing the continuously successional character of 
these two great series, as opposed to the view, that an unrepre- 
sented interval of time prevented their junction beds from being 
either closely homotaxeous or more generally contemporaneous, 
in different parts of the south-west of Ireland. The great diffi- 
culty would then appear to be how much time might be sufficient 
to produce within the same area appearances of conformity in 
one direction and utter discordance in another. Ifa long enough 
period were allowed there seems to be no impossibility in the 
case, and that there must have heen both sea and land somewhere 
in the neighbourhood, however, near or remote, even in the 
period of the Dingle and Glengariff beds, may be inferred from the 
existence of land or marsh plants in these presumably marine 
strata,* 
* Such land need not, however, have been very near, for I have found cast upon the 
beach at Derrynane bamboos and such tropical flotsam, which, even if derived from some pass- 
ing ship, must have travelled far in the sea water, to become so highly saturated with its 
salt as was the case. 
