284 
EOCENE OR OLDER TERTIARY. 
be defined only t>y numerous competent observers. If in the table of superposition 
(and in the Map), we have endeavoured to separate the miocene (No. 9.) from 
another group, Pliocene ?, which we term Aralo-Caspian (No. 10.), we must beg 
our readers to understand, that in a few districts over which the colour of the 
younger deposit is extended, the older beds are also present in the same natural 
sections. This point will be explained in the sequel, when we come to separate 
the deposits of oceanic character from those named Aralo-Caspian, which cover 
such immense tracts in Asia. 
With these prefatory remarks, we may now say a few words upon each of these 
Russian accumulations. 
I. Eocene or older Tertiary (No. 8. of Map ). — ‘Sections have already been cited, 
in which beds equivalent to the calcaire grossier and London clay, are seen in 
connexion with strata which we refer to the upper part of the Cretaceous system. 
A mid vast spaces of Russia as yet little explored by geologists, there is every reason 
to hope, that notwithstanding the superficial detritus which obscures the rocks, and 
the small comparative elevation of the land, other sections will yet be found, to 
show more completely, both the order of superposition and the sequence of organic 
life, and to indicate the existence in these undisturbed regions, of a passage from 
the cretaceous to the tertiary system. 
In the Crimsea, indeed, and particularly near its southern shores, where the rocks 
are much more elevated and clearly exposed, the first beds in natural ascending 
order above the white chalk, are those which contain Nummulites, with Ostrea 
latissima, and a gigantic Cerithium : they are classed by M. Dubois with the Creta- 
ceous system, but, according to M. Huot and other geologists, are included in the 
tertiary series. These intermediate beds are, it is believed, of the same age as 
certain strata along the northern flanks of the Pyrenees, the relative antiquity of 
which has recently undergone much discussion ; MM. Dufrenoy and E. de Beau- 
mont claiming them as appanages of the chalk, because they have undergone some 
of the great elevatory movements by which that deposit was affected, whilst their 
opponents contend, that as they contain some of the characteristic fossils of the lower 
tertiary beds of the basin of Paris, they must be classed with that formation. As one 
of us only has some personal acquaintance with the Crimcea, we do not consider 
this a fit occasion to enter much into a controversy, which cannot be determined 
without a very circumstantial appeal to facts and fossils. Reference will, however, 
be again made to this subject, and a thin band is left in the table appended to the 
