13k Scientific Proceedings, Royal Dublin Society. 
and as it was found impossible to draw a boundary between these 
beds and the Old Red Sandstone, the whole of the beds were 
massed under the colour of this latter formation. In both dis- 
tricts, however, viz, those north and south of Dingle Bay, a 
separation has been made on the map of Sir R. Griffith; and as 
the author concurs with the view adopted by so eminent an au- 
thority, and can have no doubt but that the greenish grits and 
green and red slates of the Reeks and Killarney Mountains are the 
actual representatives of the “ Dingle beds,” he has followed Sir 
R. Griffith’s map in this instance also. The author does not offer 
any opinion on the age of “the Dingle beds,” though inclining to 
the view that they are Upper Silurian; nor does he think that 
much reliance can be placed on thé divisional line between these 
beds and those of the Old Red Sandstone in the promontories 
north and south of Kenmare Bay.* 
3rd. The third alteration refers to the Carboniferous districts. 
On Jukes’ map the whole of the beds above the Carboniferous 
limestone are represented under one dark colour, as “coal- 
measures.” On the new map an attempt has been made to re- 
present at least three divisions in this group—1l. The “ Yoredale 
shales ;’ 2. “Millstone grit ;’ and 3. Lower and middle Coal- 
measures. The progress of the Government survey has rendered 
this possible in all the Carboniferous districts but those of the 
S.W. of Ireland, where the details are not yet worked out, and 
where consequently the divisions are only tentative. 
Ath, Lastly, in representing the trap rocks, whether contempora- 
neous or intrusive, an attempt has been made to separate, and 
show by distinct colours, the pyroxenic from the felspathic—the 
former including diorite (“greenstone”), dolerite, basalt, &c., the 
latter including quartziferous porphyry, felstone porphyry, feistone, 
trachyte, &c. Many of the principal faults are shown by white 
lines. 
* Since the above was written, the author, having visited these districts, has come t 
the conclusion that the Old Red Sandstone is absent in some places. 
