Vol. 69.] PALAEOZOIC ROCKS OF THE CATTTLEY DISTRICT. 13 



The above-mentioned graptolite has been found in the Descrt- 

 creat Beds of Tyrone. 1 It has also been recorded by me in the beds 

 at Norber Brow in the Settle District. 2 There is no doubt that 

 these beds are Ashgillian, and represent the Staurocephalus Beds of 

 the Cautley District. 



In the Lake District, I divided the Ashgillian Series into a lower 

 group, Staurocephalus Limestone, and an upper, Ashgill Shales. 3 

 The identity of the Ashgill Shales in that and the Cautley districts 

 is clear, but the Staurocephalus Limestone of Lakeland presents the 

 lithological characters and fauna of the uppermost division only of 

 the Cautley Staurocephalus Beds (the Phacops-mucronatus Band). 



The fauna of the bulk of the Staurocephalus Beds and of the 

 Phacops-robertsi Beds appears to be wanting in Lakeland. This 

 may be due to an unconformity (which occurs below the Ashgillian 

 Series in South Wales), or some of the beds referred to the Sled- 

 dale Group may be really Ashgillian. I suspect the former, but 

 further work is required in Lakeland. 



In the Cross-Fell inlier it is more probable that some of the beds 

 referred to the Sleddale Series are actually Ashgillian. It may be 

 noted that the Sleddale (Calymene) Beds of Cautley lithologically 

 resemble those of the Cross-Fell inlier more than those of Lakeland ; 

 and I suspect, from the occurrence of certain fossils high up in the 

 Dufton Shales of Swindale Beck, that the upper part of the Dufton 

 Shales may have to be removed from the Sleddale Group (Cara- 

 docian) and placed in the Ashgillian. 



The succession in South Wales can at present be more satis- 

 factorily compared with that of Cautley. The Staurocephalus of 

 Pelcombe Cross is unaccompanied by Phacops robertti, and, con- 

 versely, the former fossil is not recorded from the Ph.-robertsi Beds 

 of Prendergast. It would seem that the beds termed ' Sholeshook 

 Limestone Group ' by the late Mr. T. Roberts & myself, 4 which 

 include the above-named deposits, may be divisible into a lower 

 and an upper series characterized by the Phacops and the Stauro- 

 cephalus respectively. The similarity of the higher beds in the 

 two areas has been noted by me,' and needs no further remark. 



The notes in the paper just cited also render it needless to com- 

 ment upon the relationship between the Ashgillian Series of 

 Cautley and that of other areas. 



In conclusion, the development of the Ashgillian Series in the 

 North of England is far more satisfactorily shown around Cautley 

 than in the neighbouring areas of the Lake District and Edenside ; 

 and I have described this Cautley succession as one which should 

 be taken as the type for the Ashgillian Series of Northern 

 England. 



1 See W. Gr. Fearnsides & others, Proc. Roy. Irish Acad. voL xxvi, sect. B 

 (1907) p. 111. 



2 Geol. Mag. dec. 3, vol. iv (1887) p. 36. 



3 Ibid. dec. 3, vol. ix (1892) p. 97. 



1 Q. J. G-. S. vol. xli (1885) p. 480. 



5 G-eol. Mag. dec. 5, vol. iv (1907) p. 65. 



