GLENGARIFF GRITS AND SLATES. 
715 
Representative beds of the Upper Silurian Series in Kerry and 
Mayo and Galway. 
Kerry (including Dingle). 
3. Upper Slate Series.—Bright red 
and purple slates, forming the shores 
of Dingle Harbour, also underlying 
the Lower Carboniferous beds at 
Sneem, Kenmare, Glengariff, &e. 
3000 feet. 
2. Glengariff-grit and Ferriter’s- Cove 
Series.— Massive green grits, sometimes 
pebbly, with beds of slate (Reeks and 
Killarney and Glengariff mountains, 
Great Blasket Island, &.). The slate 
series of Dunquin coast, Ferriter’s 
Cove beds, with volcanic ashes and 
traps, fossils of Wenlock and Ludlow 
species. About 10,000 feet. 
1. Smerwick and Sybil-Head Beds. 
—Lying at the base of the Dingle 
section. Purple and brown and green 
sandstones, flagstones, and shales (no 
fossils). At Bull’s Head, on the slope 
of Caherconree, Llandovery species 
West Mayo and Galway. 
8. Salrock Slate Beds. —Bright red 
slates and shales, with bands of grit 
and one of limestone. Lingula Sy- 
mondsii, Pterinea retrofleca, Trochus 
multitorguatus. About 3000 feet. 
2. Mweelrea Beds.— Green and pur- 
ple grits, conglomerates, with beds of 
slate and shale. Volcanic ashes and 
felspathic lavas in the lower beds. 
Fossils of Wenlock and Ludlow spe- 
cies, 8000 feet. 
1. Owenduff Series (Upper Llando- 
very).—Green and grey grits, sand- 
stones, shales, with brecciated lime- 
stone, with volcanic ashes and traps; 
base generally a conglomerate. Fos- 
sils :-—Favosites fibrosus, Cyathophyl- 
have been found, Favosites alveolaris, 
Cyathophyllum (Petraia) elongatum, 
Atrypa hemispherica, &e. 
lum elongatum, Encrinurus punctatus, 
IWlenus Bowmanni, Orthis  reversa, 
Atrypa hemispherica, Trochus multi- 
torquatus, &e. About 2000 feet. 
From the comparisons above it will be observed that there is no 
essential difference between the sections in the two districts recor- 
ded. In both the fossils are chiefly plentiful in the beds represen- 
ting the Llandovery and Wenlock series; and if in the upper beds 
of the Dingle series they are absent or scarce, such is also the case 
with the Mweelrea beds in Mayo. As regards thickness, both sec- 
tions are incomplete; but we find in each case a great development 
of sedimentary strata, surpassing that of their representatives in the 
Silurian border districts of England and Wales, in which calcareous 
beds occupy a prominent position. To this feature I propose to 
return further on. 
Volcanic Products.—Another feature of resemblance between the 
beds of the two districts, that of Dingle and Killarney, is the occur- 
rence in both of the products of contemporaneous volcanic action. 
In the former district these are opened to us along the coast N. of 
Dunquin Harbour amongst the beds of the Wenlock and Ludlow 
stage, and on a large scale (fig. 1). They are several hundred feet 
in thickness, consisting of beds of felspathic ash and lapilli, more or 
less consolidated, traversed by cleavage-planes and passing from the 
condition of an agglomerate to that of the finest powder. The ge- 
neral dip corresponds to that of the Silurian beds, being south at 
25°-30° ; and immediately north of the entrance of Dunquin Har- 
bour or Inlet there occurs a mass of intrusive greenish felstone, about 
- 100 yards across, which may possibly be the consolidated lava filling 
