CLASSIFICATION OF THE DEVONIAN AND CARBONIFEROUS ROCKS. 65 
In the western part of the county of Cork, as at Dunworley Bay, 
Dirk Bay, and, near Skibbereen, the Coomhola grits contain a very 
remarkable assemblage of fossils. Together with some species of Ac- 
tinocrinus, identical with those from the Carboniferous rocks, Rhyn - 
conella pleurodon, Spirifer cuspidatus , and Spirifer disjunctus (or at 
least the variety of that Spirifer which is commonly called Spirifer 
Verneuilli ), there have been found numerous bivalve shells, most of 
them of new species, and some of them apparently of undescribed 
genera. These shells belong to Modiola, Cucullsea, Avicula, Aviculo- 
pecten, Axinus, Nucula, and a new genus for which the name of Cur- 
tonotus (Salter) is proposed. The latter is peculiarly characteristic 
and abundant; it is also found on the same horizon in Pembroke¬ 
shire and North Devon. Bellerophon, rounded, sharply keeled, and 
trilobed species, with spiral shells and Orthoceras, and a new Lingula 
of large size, are not unfrequent. The Cuculkeee are large, and appear 
to be distinct species from those of North Devon; but the Avicula 
Damnoniensis is identical with the English species, and more abun¬ 
dant in the above localities than any other shell. The Rhynconellapleu- 
rodon , both of large and small size, is also very abundant. 
In the section of the Glen of Coomhola, and along the shores 
near Glengariff, these beds are better exposed, and more accessible, 
than in any other spot. A close search in them discovered abundance 
of the shells above mentioned, at least of the characteristic Avicula, 
and also the Cucullcea trapezium of Devonshire. Nor were the plants 
absent, for large specimens of the Knorria dichotoma occurred at in¬ 
tervals throughout the Coomhola grits, as well as in the shales of the 
Upper Devonian below them. 
The evidence, therefore, so far as it has yet been collected 
throughout the south of Ireland, w^ould point to the following con¬ 
clusions :■— 
First, that no marine remains are to be found in the “ Yellow 
Sandstone” of the south of Ireland, which is the upper part of the Old 
Red Sandstone, but that the same species of plants are found through¬ 
out it wherever there are green shales or slates, or yellowish sand¬ 
stones, present in it. 
Second, that the Carboniferous slate, whether more or less deve¬ 
loped, contains, throughout all its upper portion at least, the ordi¬ 
nary Carboniferous types, as long ago stated by Dr. Griffith. 
Thirdly, that a considerable, but locally developed group of 
H 2 
