304 DE. A. VATJGHAN" OK THE FAUNAL SUCCESSION [May I906, 



5. The Curkeen Limestone. 

 (See special faunal list, p. 299.) 

 Analysis : — 



(i) Corals : 



Litliostrotion cyathop7iylloides, mutation towards Koninckopliyllum 

 (cf. K. 6 of D x , South-Western Province), and Clisiophyllum 

 curJceenense both show marked development from the forms in the 

 ' Megastoma-Beds/ 



Cyaihacconia contorta occurs also in the ' Cyathaceonia-Beds.' 

 The Curkeen Limestone, therefore, should lie above the ' Mega- 

 stoma-Beds' and near the horizon of the ' Cyathaxonia-Beds.' The 

 stage of development suggests D r 



(ii) Brachiopods : 



The Producti indicate a somewhat lower level than the 

 ' Cyathaxonia-Beds.' 



(1) Fimbriate or pustulose types are abundant. 



(2) Highly-developed scabriculate types are absent, as also are the most 

 specialized members of the semireticulate group (such as Productus 

 longispinus) and the characteristic Pr. margaritaceus. 



The Chonetes are convex papilionaceans. 



Schizophoria resupinata is very abundant, and exhibits much 

 individual variation of form : all its varieties could, however, be 

 matched from Wetton, Astbury, etc. 



Athyris glabristria also attains its maximum development, as it 

 does at Kniveton in the Midland area. 



Camarophoria aff. isorhyncha and Leptcena cf. distorta, together 

 with the three species just cited, are common to the ' Cyatliaxonia- 

 Beds ' and the Curkeen Limestone. 



The Spirifers belong to the striate group, and are apparently the 

 descendants of the forms which make their first appearance in the 

 ' Megastoma-Beds ' of the Rush sequence and in the Syringothyris- 

 Zone of the South-Western Province. 



Martinia glabra is abundant : in the South-Western Province we 

 only know this form from D 2 (Oystermouth Limestone) ; it is 

 common in the Park-Hill fauna. 



Derby a anomala is identical with the Park-Hill form. 



General conclusion: — The Curkeen Limestone cannot occur 

 at any considerable distance from the ' Cyathaxonia-Beds,' and, 

 with great probability, lies immediately below them in some part 

 of the Upper Dibunophyllum-Zone. 



