678 MR. J. E. MAER AND DR. H. A. NICHOLSON 



are unweatliered and of a greyish "black. It is more difficult to obtain 

 exact measurements in this stream than in the cliffs of the rake, but 

 the thickness given above seems to hold good here also. The 

 calcareous band which we have taken as marking the base of the 

 Upper Browgill Beds is seen in the stream about halfway between 

 the cascade over the Coniston Limestone and the quarry in the 

 Coniston Flags by the stream, north of the hamlet. Above it is a 

 thickness of pale green and reddish-purple grits and shales, passing 

 gradually up by the intercalation of grey bands into the blue-grey 

 Coniston Plags. An approximate measurement shows the occurrence 

 of about sixty feet of these shales between the calcareous band and 

 the base of the Coniston Flags, which gives a thickness of about 130 

 feet for tbie whole of the Browgill Beds in this locality. 



The chief features which distinguish the Upper Browgill Beds 

 from the Lower ones are : — 



(i) The absence of Graptolitic shales ; 

 (ii) The occurrence of more massive grits ; 



(iii) The reddish-purple colour of some of the beds. 



The latter distinction appears to be due to the staining of the 

 beds subsequently to deposition, and it is therefore of little value 

 for classificatory purposes. In some sections along the outcrop of 

 the Stockdale Shales the staining is absent; in other places it 

 penetrates even to the Lower Browgill Beds, and usually takes place 

 among the softer and more shaly deposits. The colouring material 

 seems, however, to have been introduced from above, so that when 

 staining does occur, it affects the Upper Browgill Beds far more 

 than the Lower Beds, which are, indeed, usually entirely unaffected 

 by it. 



To sum up the results of the examination of this section : — 



Ba. The Lower Browgill Beds are divisible into : — 



Ba 1 . Twenty-one feet of pale shale with a band, one inch in 

 thickness at the summit, marked by the occurrence of M. tarricu- 

 latus, Barr. : =Zone of M. turriculatus. 



B« 2. A set of pale shales 15 feel thick with many Graptolitic 

 bands, having 19 feet of pale shales below and 10 above, total 44 

 feet, containing Monograptus crisjms, Lapw., M. eooiguus, Mch., &c., 

 in abundance : =zZone of M. cris]pus. 



B6. The Upper Browgill Beds are divisible into : — 



B6 1. A mass of calcareous blue mudstones with some paler beds, 

 marked by the occurrence of calcareous nodules, and 7 feet 6 inches 

 thick. 



B6 2. A series of pale green and reddish-purple shales with 

 massive grit beds, the whole attaining a thickness of about 60 feet. 



It will be noticed that the calcareous band occurs about the 

 centre of the Browgill Beds, and therefore forms a convenient line of 

 division between the Lower and Upper Beds. 



It sbould be mentioned that the Graptolites of the Browgill Beds 

 of Stockdale and of Browgill are very rarely preserved in relief, and 

 this is true of the Graptolites of the same beds in all parts of the 

 district. 



