CARBONIFEROUS FAUNA OF RUSSIA. 
135 
everywhere the very same as those of our own countries. Among the most com- 
mon of these shells are the P. giganteus and P. striatus (both characterizing the 
lower beds), the P. antiquatus and P. punctatus ; all well known as the most com- 
mon forms of the British mountain limestone. 
The Spirifers offer less variety than those of England, and we are not able to 
enumerate more than seven or eight species. The most remarkable and most 
generally diffused is the Spirifer Mosquensis , which invariably characterizes the 
central mass or white limestone of Russia, and is never found in the lower stratum. 
The most prevalent corals are the Chcetetes radians, Lithostrotion floriforme , the 
undescribed species of the English mountain limestone to which we have often re- 
ferred, the Gorgonia retepora, and Retepora laxa. In the Ural Mountains and on 
their flanks, the two latter polypifers are highly useful in enabling us to distinguish 
the carboniferous from the Devonian limestone, when these rocks graduate into 
each other, and are subjected to the same flexures. Gorgonias and Retepores, we 
may observe, are evidently of the latest creation among the corals of the palaeo- 
zoic rocks, for they occur even in the overlying Permian deposits. 
Encrinites are not wanting in the carboniferous limestone of Russia, but they 
seem to be less abundant in it than in England, and the heads or stomachs of 
these animals, by which alone their specific characters can be well determined, jire 
exceedingly rare. 
Lastly, the creatures which, approaching to the lowest scale of organization, 
particularly attract our attention as peculiar to the carboniferous deposits of Russia, 
are the Fusulinse, foraminifers closely allied to the genus Nonionina of D’Orbigny 1 2 . 
Russia is the only country in Europe in which such minute beings are found 
so low in the series of deposits, and there they so abound, that, like the Num- 
mulites of the older tertiary and youngest secondary deposits, they constitute thick 
masses of rock ; and from the fine lamination ot the strata, seem to indicate the 
existence of a very tranquil sea, during the long time throughout which they 
were accumulated. We have described such rocks upon the Volga near Samaia, 
1 Mr Lonsdale had not completed his examination of the corals whilst these pages were in the press, 
and his account of them will appear in Part III. In the mean time he has decided, that the Lithostrotion 
floriforme must he called L. emarciatum, Fischer having described it as Astrm ernarciata. 
« Whilst these pages are passing through the press, M. Alcide D’Orbigny, having examined the Fusu- 
lina, has enabled us to correct our comparison of this foraminifer (p. 87) with the Alveolina, which it 
very much resembles in external form. See description, Part III- 
T 2 
