GLENGARIFF GRITS AND SLATES. 705 
break or evidence of discordance in the succession of the beds; on 
the contrary, the change is gradual, with intercalations, and the 
whole series gives evidence of continuity. 
In fine, after a careful observation of the sections near Dunquin, 
we came away fully impressed with views regarding the relations of 
these beds similar to those expressed by the late Sir R. Griffith, that 
the whole series is one and indivisible, and represents the Upper 
Silurian beds from the base throughout. 
Evidence of Age from Fossils. 
I have already stated that the uppermost fossiliferous band in the 
coast-section at Dunquin might be regarded as occurring in “ the 
Dingle series,” as the purple slates which underlie it are precisely 
similar to those which overlie it, and are supposed to belong to the 
** Dingle series.” Except, however, for the presence in the beds of 
purple slate of remarkable “ fucoidal’’ markings, it must be admitted 
that the Dingle beds and Glengariff grits and slates are lamentably 
destitute of fossil forms. It must be recollected, however, that the 
strata are not favourable to the preservation of such forms, even 
supposing they once existed ; and we have only to refer to some well- 
known marine formations of similar composition to feel assured that 
the absence of fossil forms is no argument against the marine origin 
of the Dingle beds. For example, it is rarely that any traces of 
fossils are found in the “ Bala and Caradoc” grits and slates, which 
occupy so large an area of the north-east of Ireland. The fossils 
which occur are sporadic and local, but hundreds of feet of strata 
may be examined over many square miles without rewarding the 
search of the collector. 
Another very apposite illustration occurs in the case of the ‘* Morte 
Slates ” of the Devonian series, attaining a thickness of from 3000 to 
4000 feet in the Devonshire section, and succeeding the highly 
fossiliferous beds of the ‘‘ Ilfracombe group.” ‘These slates are un- 
fossiliferous; but it is improbable that they have not, like the 
beds below them, been deposited in the sea. Many other instances 
might be cited in support of the view that, notwithstanding the 
absence of marine fossils, the beds we are considering may really be 
of marine origin. Before, however, we admit that the Dingle beds 
are really destitute of fossils, let us consider the evidence offered by 
the Parkmore-Point Conglomerate. 
Parkmore-Point Conglomerate. 
Amongst the highest beds of the Dingle series there occur some 
massive conglomerates forming the cliffs at the entrance to Ventry 
and Dingle harbours, and particularly well laid open at Parkmore 
Point. The pebbles are large, well rounded, and formed of various 
kinds of grit, quartz, hornstone, fragments of purple slate (or schist), 
white ash, vesicular greenstone, and purple fossiliferous limestone, 
or highly calcareous grit. From some of the pebbles Silurian fossils 
were determined by Mr. Salter in 1856*. 
* “Explanation” of sheets 160, 161 &e., of the Maps of the Geological 
Survey, p. 24. 
