194 THE 0RD0V1CIAN AND SILTJEIAN ROCKS OF CONWAY. [May I909, 



in the Bala as Mr. Thomas had suggested. It might be possible 

 to recognize the horizon where a limestone (such as the Mydrim 

 Limestone) immediately underlay the shales ; but, where the 

 calcareous facies did not occur, she thought that it would be 

 found that a similar fauna would extend down into much lower 

 beds. 



With regard to the point raised by Mr. "Whitaker, the Author 

 stated that she had traced the Calcareous Grits for a considerable 

 distance in a southerly direction ; and, although she had not 

 mapped the Hirnant area, she had every reason to believe that 

 the beds overlying the limestone were the same as those in the 

 Conway District. 



