Vol. 51.] IN THE ' PEKMIAN ' KOCKS OP WYKE FOREST. 535 



gave rise to the idea that it might possibly have been drifted from 

 other Coal Measure areas. 



This, however, was clearly not the case, as the fragments always 

 occupied the same relative position with respect to the boundary 

 between the red and the yellow rocks. Besides, there is an entire 

 absence of loose blocks of any other rocks than those which occur 

 in situ in the sides of the streams themselves. 



The lumps first observed yielded no fossils, but the fact that the 

 limestone showed a general resemblance in colour, texture, fracture, 

 and in bituminous smell to the limestone from other bands, and which 

 in other localities is fossiliferous — for example, at Hamstead — sug- 

 gested that the limestone here under description would subsequently 

 be found to contain the characteristic annelid. 



A mass picked up at the ponds in the north-western part of 

 Arley Park first showed what looked like a weathered specimen of 

 the fossil ; and I have since found fossils in the specimens from a 

 number of different and distant localities. 



The constancy in position wherein the fragments of the limestone 

 occurred — that is, in close proximrty to, but on the upper side of, 

 the lower boundary of the ' Permian ' — soon suggested the idea that 

 realty the limestone occurs on one definite horizon as a more or less 

 continuous band. This band had not yet been discovered in an 

 interbedded condition. 



There is, however, a faulted mass of • Permian ' cut through by 

 the Severn Valley Eailway (G.W.B.) at Stanley, on the south side 

 of Highley Station, 2 miles above Arley, which ultimately proved 

 to contain the limestone exposed in an interbedded condition. I 

 shall advert to this section presently in describing the course of the 

 outcrop. 



(2) General Description of the Limestone. 



The limestone occurs in two varieties of colour : — (i) A dark grey, 

 almost black, variety ; and (ii) A light greyish-brown variety. Both 

 occur in the same band, and frequently in the same block. The 

 dark variety is perhaps richer in Spirorbis pusillus than the light 

 one, is rougher in its fracture, and when freshly broken emits an 

 unmistakable bituminous smell. 



The light-coloured variety is hard, brittle, very fine-grained, and 

 compact, breaking with a somewhat flinty fracture. It emits no 

 bituminous smell when broken, and is apparently less fossiliferous 

 than the dark variety. 



Both kinds differ somewhat in appearance from specimens of the 

 lower band in the ordinary Coal Measures, for example, at Arley 

 Kings near Stourport, and at Tasley near Bridgenorth : these being 

 apparently more earthy, less compact and smooth-fractured, and 

 more highly charged with fossils. The lower limestone seems, more- 

 over, to be generally light-coloured. 



