288 HISTORICAL PALZXONTOLOGY. 
the Isle of Wight be placed in the Middle Eocene, the only 
British representatives of the Upper Eocene are the Bembridge 
beds. These strata consist of limestones, clays, and marls, 
which have for the most part been deposited in fresh or brack- 
ish water. 
II. Eocene BeEpDs oF THE Paris Basin.— The Eocene 
strata are very well developed in the neighbourhood of Paris, 
where they occupy a large area or basin scooped out of the 
Chalk. The beds of this area are partly marine, partly fresh- 
water in origin; and the following table (after Sir Charles 
Lyell) shows their subdivisions and their parallelism with the 
English series :— 
GENERAL TABLE OF FRENCH EOCENE STRATA. 
UPPER EOCENE. 
French Subdivisions. English Equivalents. 
A. I. Gypseous series of Mont- 1. Bembridge series. 
martre. 
A. 2. Calcaire silicieux, or Tra- 2. Osborne and Headon series. 
vertin Inférieur. 
. Gres de Beauchamp, or 3. White sand and clay of Barton 
Sables Moyens. Cliff, Hants. 
MIDDLE EOCENE. 
> 
ioe) 
B. 1. Calcaire Grossier. 1. Bagshot and Bracklesham beds. 
B. 2. Soissonnais Sands, or Lits 2. Wanting. 
Coquilliers. 
LOWER EOCENE. 
C. 1. Argile de Londres at base of I. London clay. 
Hill of Cassel, near Dun- 
kirk. 
C. 2. Argile plastique and lignite. 2. Plastic clay and sand with lig- 
nite (Woolwich and Reading 
series). 
C. 3. Sables de Bracheux. 3. Thanet sands. 
III. Eocene STRATA OF THE UNITED StatEes.—The low- 
est member of the Eocene deposits of North America is the 
so-called “ Lignitic Formation,” which is largely developed in 
Mississippi, Tennessee, Arkansas, Wyoming, Utah, Colorado, 
and California, and sometimes attains a thickness of several 
thousand feet. Stratigraphically, this formation exhibits the 
interesting point that it graduates downwards insensibly and 
conformably into the Cretaceous, whilst it is succeeded wncon- 
formably by strata of Middle Eocene age. Lithologically, the 
series consists principally of sands and clays, with beds of lig- 
nite and coal, and its organic remains show that it is principally 
of fresh-water origin with a partial intermixture of marine beds, 
