288 Scientific Proceedings, Royal Dublin Society. 



not, however, appear necessary to go into detail in connexion with 

 these, as the object of this Paper is sufficiently answered by the 

 description already given. 



NOTE ADDED IN THE PEESS. 



In a subsequent communication reasons have been given for 

 supposing that the Bray Head Series is older than the "Welsh 

 Cambrians, and should be separated from them into a new group, 

 for which the name Oldhamians is proposed. If this suggestion 

 is correct, the Oldhamians will represent one of the series of " gap 

 rocks " of Chamberlaine's Agnotozoic Epoch ; that is, one of the 

 series of rocks which accumulated subsequent to the end of Huronian 

 time, and prior to the Primordials (Cambrians). 



