Vlll 
TABLE OF CONTENTS. 
PAGE 
CHAPTER XIX. 
The Lower Chalk in Yorkshire. 
General Description - - - - 226 
Stratigraphical Details ------ 226 
Zone of Ammonites varians ----- 229 
Zone of Ojfaster sphoericus - - - - - 231 
The Belemnite Marl - - 233 
List of Fossils ------- 234 
CHAPTER XX. 
The Equivalents of the Lower Chalk in the North-east 
of France. 
French Nomenclature ------ 236 
Stratigraphical Details - - - - - - 237 
Boulonnais - - - - - - 237 
Country of the Tourtias - - - - - - 239 
Yonne, Aube, Marne, and Aisne - - - 241 
Department du Norcl ------ 243 
Critical Remarks ------ 246 
List of Fossils ------ 248 
CHAPTER XXI. 
The Lower Chalk (Cenomanian) in the North-west of France. 
General Description ------ 250 
Stratigraphical Details ------ 250 
Seine Inferieur ------- 250 
Orne and Sarthe ------- 254 
Fossils from Vimoutiers ------ 255 
Remarks on the Correlation of Cenomanian and Lower Chalk - 258 
CHAPTER XXII. 
The Micrographic Structure of the Beds forming the Zone 
of Am. varians (by Mr. W. Hill) 
Introductory Remarks on the Methods of Examination - - 261 
(a) Chloritic Marl :—Macroscopic Aspect; Microscopic Aspect ; 
Examination of Washings ; Examination of Residues ; Tabu¬ 
lation of Results ; Summary of Chemical Results - - 264 
(b) Quartziferous Limestones of Devonshire - 274 
(c) Marls and Chalks of the Am. varians zone :—Macroscopic 
Aspect; Microscopic Aspect ; Examination of the Washings ; 
Examination of Residues ; Finest Material; Tabulation of 
Results; Summary of Chemical Results - - 276 
CHAPTER XXIII. 
Micrographic Structure of the Beds forming the Zone of 
Holaster subglobosus (by Mr. W. Hill) 
(d) The Totternhoe Stone :—Microscopic Aspect; Examination of 
Washings ; Examination of Residues ; Tabulation of Results 300 
(e) Chalk above the Totternhoe Stone :—Microscopic Aspects ; 
Examination of Washings ; Examination of Residues ; Tabu¬ 
lation of Results; Summary of Chemical Results - - 304 
(/) The Belemnite Marls :—Macroscopic Aspect; Microscopic 
Aspect ; Examination of Washings; Examination of the 
Residues • Tabulation of Results - 319 
General Summary of the Component Materials of Lower Chalk - 325 
List of Foraminifera 329 
CHAPTER XXIV. 
Chemical Composition of the Lower Chalk. 
General Remarks 332 , 
Analyses of Chalk Marls - - - - - - 332 
Analyses of Totternhoe Stone and the Chalk above it - 339 
