GLENGARIFF GRITS AND SLATES, Tey 
On the supposition that the beds on the flanks of the Killarney 
range, amongst which we find the volcanic rocks, are higher up in 
the series than those at the extremity of the Dingle promontory, it 
would appear that after the volcanic fires had become extinct in the 
latter district, they broke out in the region to the south, both, how- 
ever, belonging to the same geological period. Still later (namely, 
during the epoch of the Carboniferous limestone) there were fresh 
outbursts of volcanic forces in the adjoining region of the county of 
Limerick, resulting in the formation of two distinct bands of lava, 
the lower augitic, the upper felspathic, and separated by a consider- 
able interval of time represented by the formation of many feet of 
limestone. For examples of such intermittent outbursts in the same 
region in more recent times, we might refer to the volcanic district 
of Central France, where, along a tract of country extending for some 
fifty miles, we find a series of several hundred extinct craters, which 
were in activity at different periods ranging down from the Miocene 
into the Pliocene, or possibly even later, and where the older erup- 
tions of Mont Dor and Cantal gave place to those of the Puy and the 
Vivarais. 
Plant-remains.—Besides the “ fucoid ”’ markings which are com- 
mon amongst some of the purple-slate beds throughout the moun- 
tains of Cork and Kerry, impressions of plants, belonging probably 
to the group of vascular cryptogams, have been found in several 
places, particularly in the mountains of Iveragh and Dunkerron, by 
the collectors of the Geological Survey. These have been referred 
by Mr. Baily to the genus Sagenaria. Tracks also, probably those 
of Crustacea, have been discovered, of which specimens are pre- 
served in the collections of the Survey in Dublin. The occurrence 
- of land plants allied to those forms which predominated in the Car- 
boniferous period cannot be regarded as an argument against the view 
that the beds containing them are referable to the Upper Silurian 
period, as several instances of a similar kind have been recognized 
in North America. In this region plant-remains of the genera Lepi- 
dodendron, Glyptodendron, and Sigillaria have been found in beds 
ranging from the base of the Upper Silurian series into the Devonian 
and Carboniferous*. It is necessary to observe, however, that the 
specimens of these plants in the collection of the Survey have all 
the appearance of having been obtained from the Lower Carbonife- 
rous beds. The rock is fine greyish-blue grit, unlike that which 
prevails amongst the Glengariff beds. In either case the occurrence 
of plants does not, as it seems to me, affect the question of the age 
of these beds‘. 
* These have been mentioned by Dr. Dawson, Prof. James Hall, Prof. Less 
quereux, Prof. Claypole, and others, and are cited by the last-named observer, 
in a paper recording a fresh discovery, in Geol. Mag., Dec. 1878. 
+ Since the above was written, the spots have been re-examined by Mr. Baily, 
and there seems little doubt of the occurrence of the plants in the Glengariff 
beds. 
Q.J.G.S. No. 140. 3C 
