﻿48 



ME. T. F. SIBLr OX THE PaUXAL STJCCESSIOX IX THE [Feb. I908, 



part of the area and that in the south-western "' part. To some 

 extent, the observed differences may perhaps be apparent rather 

 than real, because sections of D^ are numerous in the eastern, 

 but fewer and far less extensive in the south-western district. 

 This factor could not, however, account for all the observed 

 discrepancies. 



The relation between the eastern and the south-western facies 

 may be summarized as follows : — 



In the eastern district, the coral-fauna includes Lonsdalia Jlori- 

 formis, LWiostrotion junc^um, Alveolites sejytosa, and Clisiophyllids 

 belonging to the ' genera ' Mistioj^hyllum, Rliodopliyllum, and 

 Cymatiophyllum. None of these corals have been recorded in the 

 south-western district. On the other hand, DibunopliyUum matlocJc- 

 ense and other corals, including Cyatlioplryllum regiinn, LWiostrotion 

 Martini, and Campophyllum derhiense, are common to both districts, 

 and in both the brachiopod-fauna is essentially identical. 



The accompanying table illustrates the difference between the 

 two facies. The typical section (Monsal Dale and Miller's Dale) 

 illustrates the eastern facies, and the AVaterhouses section exem- 

 plifies the south-western facies. Only the most predominant and 

 characteristic corals and brachiopods of the typical, eastern fauna 

 are selected for illustration. 





"Waterhouses. 



Monsal Dale 



and 

 Miller's Dale. 





* 



* 



* 



* 



* 





Cvotho'phvll'UTii vcQiiim 



^ 



Lithostroiion junceu m 



* 



Lonsdolici Horifofni is ... 



^ 



DihunophyUiiin matlockense 



Hisfiophyllum, Ehodophylhim, & 

 Cymatiophyllum 



SDir'ifc)' hisulc'otus ... . ..... 



* 



* 



4C 



Spirifer pi a n icosta 



Product us giganteus 



Productiis semireticukU us 



* 



* 







Product us jmnctatus 



* 



Martinia gl<ibra 



* 



The abnormal localized facies of this subzone represented by the 

 brachiopod-beds ' may now be considered. 

 The richly-fossiliferous brachiopod-limestones of certain localities 



^ In the north-western part of the area, -where the Lu7isdalia-suhzone has 

 been lost in places through faulting, good sections of the subzone do not exist. 



