^"S^^ 



Vol. LXXVII. 



Paet 1. 



QUARTERLY J^DURNAL 



OF THE 



GEOLOGICAL SOCIETY. 



EDITED BY 



THE PERMANENT SECRETARY. 



[With Two Plates, illustrating Papers by Mr. H. Bolton 

 and Mr. D. Davies.] 



May 13th, 1921. 



LONDON : 

 LONGMANS, GREEN, AND CO. 



PARIS:— CHARLES KLINCK8IECK, 11 RUB DE LILLE. 

 SOLD ALSO AT THE APARTMENTS OF THE SOCIETY. 



Price Seven Shillwgs and Six;penGe. 



