H 7 



THE 



QUARTERLY JOURNAL 



GEOLOGICAL SOCIETY OF LONDON. 



EDITED BY 



THE ASSISTANT-SECRETARY OF THE GEOLOGICAL SOCIETY 



Quod si cui mortaliura cordi et curae sit non tantum inventis haerere, atque iis uti, sed ad ulteriora 

 penetrare ; atque non disputando adversarium, sed opere naturam vincere ; denique non belle et probabiliter 

 opinari, sed certo et ostensive scire; tales, tanquam veri scientiarum filii, nobis (si videbitur) seadjuugant. 

 — Novum Organum, Prcefatio. 



VOLUxME THE THII ND. 



18/6. 





umm 



LONDON : 

 LONGMANS, GREEN, READER, AND DYER. 



PARIS: FRIED. KLINCKSIECK, 11 RUE DE LILLE; F. SAVY, 24 RUE HAUTEFEUILLE. 

 LEIPZIG : T. O. WEIGEL. 



SOLD ALSO AT THE APARTMENTS OF THE SOCIETY. 



MDCCCLXXVI. 



