Yol. 55.] PETKOGEAPHY OF THE EOCKS OF CONGLETON EDGE. 559 



almost entirely free from vesicles, and containing felspar, olivine, 

 and often augite. The two kinds are generally present in the same 

 thin slice, but the doleritic type, though common in the agglomerate, 

 is comparatively rare in the specimens of bedded tuff and tufaceous 

 limestone examined. On the other hand, the vesicular lapilli occur 

 more frequently in the latter rocks than in the agglomerate. 



The igneous fragments in the agglomerate are in a much better 

 state of preservation than those which occur in the four specimens 

 from the bedded and contemporaneous series north of the quarry. 



DiSCTJSSION. 



Mr. Garwood was interested to hear that Dr. Hind had recorded 

 Chonetes papilionacea from the limestone forming the central area 

 shown in the section ; he gathered from Dr. Hind's description 

 that this limestone represented the Yoredale Beds of Yorkshire, 

 which would show that species to occupy a much higher horizon in 

 the Congleton district than in Westmoreland and Yorkshire, where 

 it appeared to be confined to the Lower Mountain Limestone proper. 

 This added another proof of the difficulties attending an attempt to 

 zone the Carboniferous rocks of Britain. 



Prof. W. W. Watts and Mr. H. B. Woodwahd also spoke, and 

 Dr. Whe ELTON Hind replied. 



