Vol. 57.] PENDLESIDE GROUP AT PENDLE HILL, ETC. 365 



A richer fauna was obtained in a stream-section a quarter of a 

 mile south of Sellet Hall, in beds presumably midway between 

 the limestone-bed and the main mass. The bed was a calcareous 

 shale with nodules, and contained — 



Streptorhynchus crenistria. 



Spirifera glabra. 



Sp. trigonalis. 



JSp. phiguis. 



Froductus longispinus. 



Pr. punctatus. 



Chonetes Laguessiana. 



Athyris planosulcata. 



BkynchoQiella pleurodon, 



Edmondia unioniformis. 



Sanguinolites striatolamellosus. 



Monticulipora. 



Fenestella. 



Crinoids. 



The shale-area around the grit-outlier of Black Hill, li miles 

 west of Malham Tarn, is much confused by faults, but the position 

 of a bed of limestone and its relations with the grit on the west 

 seems to be undisturbed. The section is exposed in the bed of a 

 stream a quarter of a mile west of Black Hill, and shows a hard blue 

 limestone of some thickness, overlain by shales full of ferruginous 

 concretions. The limestone yields Productus latissimus, Strepto- 

 rhynchus a^enistria, and crinoids. The presence of the first-named 

 fossil determines the connection of this bed with the Yoredale Series 

 of Wensleydale, and shows that it may be regarded as part of the 

 Carboniferous Limestone separated from the mass by a wedge of 

 shales which thickens northward. 



A careful survey of the ground, therefore, at once demonstrates that 

 the Craven Faults have nothing whatever to do with the change of 

 type of the rocks, because the change begins some distance south of 

 the faults, is certainly not apparent between the faults, and along 

 ■the western boundary of the limestone comes on very gradually; and 

 in no place within a mile or so of the northern limb of the fault is 

 the change apparent. 



The southernmost point where the northern type is fairly developed 

 is in the flanks of Ingleboro' and Penyghent, and unfortunately 

 denudation and earth-movements have completely removed the beds 

 which would have afforded the actual evidence of the change between 

 Settle and this line. 



The theory that the change from the northern to the southern type 

 of Carboniferous rocks is abrupt and without a passage, creates 

 other difficulties. It is known that the fauna of the Carboniferous 

 Limestone practically ceases with that formation, only very few 

 species recurring in the overlying beds; and that the fauna of the 

 Yoredale limestones and shales of the northern type is practically 

 identical with that of the Carboniferous Limestone, and totally 

 different from the beds of the southern type to which the term 

 ' Yoredale ' has been applied. Could a growing fault annihilate a 

 fauna in any district, along an almost mathematically precise line, 

 unless the extent of the fault were so great and the formation so 

 rapid that it practically altered the conditions of environment 



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