86 SECTIONAL ADDRESSES. 



the earlier work of Wheelton Hind in England and of Haug in France, 

 shows them to have a value for zonal purposes in the Upper Carboniferous 

 comparable to that of the graptolites in the Lower Palaeozoic and the 

 ammonites in the Mesozoic. It may be safely stated that his paper on 

 the Carboniferous goniatites of the North of England is by far the most 

 important contribution to Carboniferous stratigraphical palseontology 

 which has appeared since Vaughan's classical paper. 



Goniatites are on the whole characteristic of the Upper Carboniferous, 

 and it is not till quite near the end of Avonian times (D^ or D,) that 

 they appear in British Carboniferous rocks in any number. As far 

 as I know, not a single goniatite has been found in the Avonian rocks of 

 the Bristol area, although in Dj and D2 are thick shales in which they 

 might be expected to occur. The D3 beds of the Bristol district are un- 

 fossiliferous quartzites or grits, but the Lower Coal Measures of Ashton,*^ 

 near Bristol, include marine bands with a typical Culm assemblage, 

 including goniatites. 



Although the non-occurrence of certain forms may commonly be due 

 to unsuitability of physical conditions, the best explanation of these facts 

 seems to be to conclude that goniatites did not migrate into the Bristol 

 area till Lower Coal Measure times. 



While as a rule the calcareous coral and brachiopod facies and the 

 shaly goniatite facies are sharply defined, rendering correlation a matter 

 of great difficulty, it has long been known that goniatites appear 

 sparingly in the Knoll limestone of Craven and the Yoredale series of 

 Settle and Wensleydale. Bands with the goniatite facies are occasionally, 

 as at Budle Bay, intercalated in the upper Bernician series of Northumber- 

 land. In the classical area of Pendle Hill, originally described by Hind 

 and Howe, and recently restudied by Parkinson, both calcareous and 

 goniatite phases are represented. 



Although as regards the highest Avonian rocks, in view of the difficulty 

 of correlating the deposits of the two chief phases, the standard phase and 

 the goniatite-lamellibranch or Culm phase, it is clear that two time scales 

 and two ?ets of zonal indices are for the present necessary I think few 

 workers on the Avonian will disagree as to the desirability of eventually 

 correlating all phases in one scale. Further, I think there will be few to 

 dispute that, partly as it is only in the case of the uppermost Avonian rocks 

 that a goniatite scale is necessary or proposed, partly owing to the fact 

 that modern work on the Avonian rocks was first put on a firm basis by 

 the study of the standard or calcareous phase, it is this development with 

 which other facies should be compared, and as far as possible correlated. 

 For the Lancastrian deposits no one can doubt that the goniatite succession 

 is the one with which any others must be correlated. 



The use of the symbol P may next be considered. Some authors have 

 used it in a chronological sense, others in a phasal sense, and others again, 

 including its original users Vaughan and Matley, partly in a chronological 

 and partly in a phasal sense. Vaughan and Matley first used it in 1908 

 for strata at Loughshinny above D^ in which a Zaphrentid or Cyathaxonid 

 facies alte nated with a lamellibranch or Culm facies. 



«« H. BoJtoa, Q.J.G.S., Ixiii. (1907), pp. 445-69, and Ixvii. (1911), p. 337. 



