294 
MIOCENE OOLITE OF SOUTH RUSSIA. 
northern shores of the Sea of Azof, we would also extend the parallel to the ba- 
sins of Vienna and Hungary. 
M. Dubois divides his tertiary deposits into four stages in the following ascending order. 1. Clay and plastic 
clay. 2. Marine sand and sandstone. 3. Oolite and Cerithium limestone. 4. Serpuline limestone, with marine 
calcaire grosier, lignites and freshwater limestone being occasionally associated. Of these bands the sandybeds 
No. 2 appear to be in that region by far the richest in organic remains ; since out of 110 species of shells which 
he describes, ninety-two are found in them, among which are many of those which we have cited from Korinitza 
in Poland. Irom M. Dubois’s description, we are strengthened in our belief, that the oolite is merely a dependent 
member of the same group ; for although it contains Cerithii and species which he did not detect in the under- 
lying sands, it is evident, that it is a continuation of the same marine series. 
The fourth member above mentioned, Serpuline limestone and marine calcaire grossier, is called by M. Dubois 
a quaternary formation. As he shows that this is clearly an overlying deposit, occasionally of great thickness, 
and as it contains Cardium lithopodolicum, with Mytili and other forms closely approaching to those of the 
Black Sea, it is probably ol true pliocene age, and ought in any detailed work to be separated from the miocene 
rocks under consideration. In our general Map, however, we group together such tertiary deposits, whether 
miocene or pliocene, so long as the oceanic character prevails in each of them. 
To beds of probably the same age as the upper marine division of M. Dubois, 
we shall hereafter allude, in mentioning certain deposits of the Crimsea and of 
Bessarabia. 
In the Museum of Warsaw many specimens were pointed out to us by Pro- 
fessor Yarocki, from various localities in Podolia, which served to convince us, 
that all the tertiary deposits of that region are of the same age as those of the 
Vistula and the Nida. Many of these shells occur in the tract between Yampol 
and Vienitza, at Machnufka, &c. They lie for the most part in earthy greensand, 
and have often preserved their colours like recent specimens '. 
The oolite of this age often becomes, as in Lower Styria 9 , a fine-grained mass, 
lithologically undistinguishable from English and French varieties of the great 
oolite of Jurassic age. Our former description of this rock in Styria, written thir- 
teen years ago, may, indeed, serve to explain its nature in the south of Russia. 
“ Some of the spherules are hollow, but others are arranged about grains of semi- 
crystalline calcareous matter, or particles of sand. The beds of true oolite are 
overlaid by irregular concretionary masses, partly oolitic, which alternate with 
unctuous sandy marl. Some of these concretions are amorphous ; some assume 
1 According to Professor Yarocki, these fossils were chiefly collected by the Polish naturalists who 
assisted Professor Eicliwald in his survey of Volhynia and Podolia ; M. Zborzewski a fossilist, and M. 
Andrzejowski a zoologist. In mineralogy and botany. Professor Eicliwald was assisted by MM. Jako- 
wicki, Gorski and Zienowicz. 
2 Geological Transactions, vol. iii. p. 397 et seq. 
