Vol. 65.] CARBONIFEROUS LIMESTONE OF COUNT! CLARE. 563 



The S 2 subzone seems to extend about a mile inland from the 

 shore-line ; but the comparative scarcity of fossils renders it a matter 

 of some difficulty to locate the approximate base of the Dibuno- 

 phyllum Zone. The floor of the Ballyvaghan amphitheatre, which 

 has a gradual slope up to about 250 feet, is formed by somewhat 

 impure limestone-beds yielding the following D, fossils : — Dibuno- 

 j)hyllum muirheadi, Lithostrotion irregulare, Clisioph)dlid Litho- 

 strotion, Productus ' aff. giganteus ', Pr. aff. hemisphericus, Pr. cf. 

 elegans, Daviesiella aff. comoides, Reticularia lineata, and Athyris 

 planosidcata . 



A well marked horizon of chert occupies the base of the two 

 rather prominent spurs which jut out from the foot of the main 

 escarpment. 



Between 250 and 500 feet the ground rises suddenly in a series 

 of vertical cliffs. The first main scarp, which occurs along this line 

 of section, immediately above the 300-foot contour-line, is formed 

 by thickly-bedded limestone, free from chert, containing Productus 

 ' aff. giganteus ', Dibunophyllum sp., and Cyathophyllum murchisoni; 

 a characteristic feature at this level, also noted in. other parts of 

 the county, is the abundance of Euomphalus acutus. At the top 

 of the second scarp Alveolites septosa and Lithostrotion junceum are 

 abundant. The ground above 500 feet, though rising in a number 

 of minor scarps, has a gradual slope up to the summit (939 feet). 

 Fossils are everywhere extremely scarce, though the occurrence of 

 Cyatliopliyllum regium at certain levels suggests that the D 2 sub- 

 zone has been reached. Productus giganteus, a large Chonetes 

 cf. compressa, Carcinophyllum sp., and Lithostrotion junceum were 

 also recorded. Chert is once more found in abundance near the 

 summit. 



The limestone-beds immediately below the Pendleside Shales 

 were examined in the region around Slieve Elva, but with the 

 exception of crinoid fragments and a small Chonetes, they appeared 

 to be devoid of fossils. Dr. Wheelton Hind, however, has recorded ] 

 Pterinopecten papryraceus, Glyphioceras diadema, and Lithostrotion 

 sp. from the topmost beds of the limestone in the neighbourhood 

 of Lisdoonvarna. The presence of the last-named genus is some- 

 what remarkable, for in other parts of the county it is typically 

 absent at this level, which is characterized by Densiphylloid 

 Zaphrentids and Caninia. The evidence thus suggests, either a 

 slight local unconformity, or merely a difference in bathymetrical 

 conditions. 2 



1 See Bibliographical List, § IX, p. 582. 



2 Though I have explored most of the surface of the Burren plateau, a 

 stretch of bare rock over 100 square miles in extent, it was found impossible 

 to furnish any connected results of zonal value : I must, therefore, of necessity 

 omit an account of this wild and remarkable district. 



