Vol. 65.] CARBONIFEROUS LIMESTONE OF COUNTY CLARE. 5G9 



Western Province of Great Britain is based on the following 

 facts : — 



1. The abundance throughout of simple Dibunophylla. 



2. The absence of more advanced Clisiophyllids, including Lonsdalia, and 



of Cyathophyllum regium. 



3. The maximum of Cyathophyllum murchisoni. 



4. The gradual replacement of Lithostrotion martini by L. irregulare and 



L. junceum. 



5. The presence of Clisiophyllid Lithostrotions. 



6. The abundance of Alveolites arid Syringopora geniculate;,. 



7. The abundance throughout of Productus ' aff. giganteus.' 



8. The occurrence of Productus hemisphericus and Davicsiella aff. comoides. 



D 2 = subzone of Lonsdalia floriformis. 



The fauna of this subzone is very scanty, and corals are poorly 

 represented; brachiopods, too, are nowhere abundant, and there is 

 mo evidence of the existence at this period of a ' knoll-phase,' such 

 as occurs in the Midlands. 



A correlation with the D„ subzone of the South- Western and 

 Midland Provinces of Great Britain is based on the following- 

 facts : — 



1. The occurrence of highly specialized Clisiophyllids. Lonsdalia dupli- 



catct, as in the Midlands, is here abundant in the topmost beds. 



2. The relative abundance of Cyathophyllum regium. 



3. The abundance of Lithostrotion junceum. (Compare the Midlands.) 



4. The abundance of Productus giganteus and Pr. ' corrugato-hemi- 



sphericus '. 



D 3 = subzone of Cyathaxonia rushiana. 



The topmost beds of the limestone in County Clare contain a 

 fauna which is distinct from that of the Lonsdalia subzone and 

 bears a marked resemblance to that of the Cyathaxonia Zone of the 

 Midlands, the Push sequence, and the upper D beds of Oystermouth 

 (Gower). 



Cyathaxonia, the subzonal index, has not been recorded, and 

 such forms as Beaumontia and Cladochonus are either absent or 

 extremely rare. 



The facts on which the correlation is based are : — 



1. The abundance of Densiphylloid Zaphrentids — Zaphrentis euniskilleni 



and Z. oystermouthensis. 



2. The common occurrence of Caninia aff. cornucopia (Amplexi- 



Zaphreniis). 



3. The absence or great rarity of Clisiophyllids, including Lonsdalia. 



4. The absence of Lithostrotion} 



5. The abundance of scabriculate, costate, and punctate Producti. 



1 Dr. Wheelton Hind has recorded Lithostrotion from the topmost limestone- 

 beds in the neighbourhood of Lisdoonvarna. 



