280 



THE GEOLOGIST. 



argiles ostreennes and argiles a plicatules, of Bailly-aux- 

 Forges, Wassy (Haute Marne), which we find also at Vil- 

 leneuve, between Erve and Marolle (Aube), and in the envi- 

 rons of Auxerre (Yonne). The lower green sand of Mr. 

 Fitton ought to be placed in this group. 



2nd Group. Gault. — Glauconie sableuse of M. Brong- 

 niart^ the gres vert inferieur and gault of the French, the 

 blue clay, blue marl, gault and gait of Mr. Smith, the loioer 

 green sand of the English, grilner Sandstein of M. Boue. 

 This is the groupe moyen of M. d^Archiac. I also divide it 

 into two series of deposits. 



The Lower Gault, comprising the clay of Wissaut 

 (Pas-de-Calais), the sandstones of Macheromenil (Ardennes), 

 Varennes (Meuse), Copt-Point, Remgeuer and of Lyme- 

 Regis and Ridge (England). 



The Upper Gault, comprising the clays of Gaty, Mau- 

 repaire, Ervy, &c. (Aube), of Valcourt, Droyes, Montier-en- 

 Der (Haute-Marne), Saint Florentin (Yonne), Senefontaine 

 (Oise), the green sands of the Perte du Rhone (Ain), Cap la 

 Reve (Seine-Inferieure), the green sands of Escragnolle (Var), 

 the black rocks of the Mountain of Fis (Savoy), &c. 



3rd Group. Chloritic Chalk. — Glauconie crayeuse 

 of M. Brongniart, the gres vert superieiir, craie tufau, craie 

 blanche and craie superieure of the French, the upper green 

 sand, chalk marl and chalk of the English, and the Chlo- 

 ritische Kreide of the Germans. 



Lower or Chlorite Chalk. I comprise in this the 

 upper green sand, the tufaceous chalk of Cape Gris-nez 

 (Pas-de-Calais), of Rouen and Havre (Seine Inferieure), the 

 green sand of Honfleur (Calvados), the chalk a baculites of 

 Valogne (Manche), the tufaceous chalks and green sands of 

 Sarthe and the banks of the Loire, the green sands of 

 Uchaux (Vaucluse), Auxon, Laubrecel (Aube), Montblainoille 

 (Meuse), Malle d'Escragnolle (Var), Vergons, Bareme (Basses 



