114 THE EARLY DEFENSIVE EARTHWORK ON COMB MOSS. 



For the benefit of readers who are not geologists, it may 

 be well to intimate that the region belongs to the Millstone 

 Grit division of the Carboniferous series, and that the Geolo- 

 gical Survey mapped and named separately each bed of stone, 

 thick belts of shale parting the several members. 



The Memoirs from which the quotations are taken contam 

 a mass of technical information, and to them those who are inter- 

 ested in geology are referred. 



