Chap. XII.] 
CAKBONIFEEOUS FOSSILS. 
297 
probable reelevation (with occasional sand-drifts), though good in such exam- 
ples as those of the South- Welsh and Newcastle coal-fields in England, as also 
of the large coal-fields in British North America, to which Sir C. Lyell has 
called attention *, can scarcely have an application to those other seams of coal 
which, as before mentioned, are interstratified with beds containing marine shells, 
the animals of which, such as Producti and Spirifers, must have lived in com- 
paratively deep sea-water f . 
In such examples (and many of the older coal-beds come into the category) 
we may, on the contrary, endeavour to explain the facts by the supposition that 
ancient streams, like the present Mississippi and other large rivers, which flowed 
through forests on low lands and mud-banks, transported great quantities of trees, 
leaves, and roots entangled in earth, and deposited them at the bottom of adja- 
cent estuaries, or that these heaps of vegetable matter were carried as floating- 
masses into the open sea. 
The coasts of Northumberland and Berwickshire, as well as the large tracts of 
Scotland already alluded to, exhibit fine proofs of such conditions. The coal- 
field of the Donetz in Southern Russia, between the Don and the Dnieper, was 
described by myself and associates as a striking example of similar relations. 
There, as in Scotland, (besides numerous beds of shale and sand with remains of 
Plants) bands of limestone, charged with species of Productus, Spirifer, Bellero- 
phon, Nautilus, and other marine Shells, and many Corals, alternate several 
times with grits, sand, and shale charged with coal J and filled with casts of 
terrestrial Plants, including Ferns, Sigillaria, Lepidodendron, Calamites, &c. § 
General Observations on the Organic Remains of the Carboniferous Rocks. — In 
treating of the general physical relations of the Carboniferous rocks of the British 
Isles, and of some changes which they have undergone beyond the region of 
the annexed map, it has been stated that in the South of Scotland, with the ex- 
ception of the lowest strata, which are of estuarine origin, the greater part of the 
coal is interstratified with limestones containing the remains of marine animals. 
Most of the fossils, indeed, of those coal-tracts, such as Nautilus, Productus, 
and Spirifer, with Crinoidea and Crustacea, unquestionably inhabited the sea. 
Even in the lowest or estuarine zone of Scotland, large Sauroid Fishes, Mega- 
lichthys Hibberti, Agass., and Holoptychius Hibberti, Agass., were associated 
with the Shark-like Fishes Gyracanthus formosus, G. tuberculatus, Ctenacan- 
thus, &c. In the great central limestones remains of these Placoid Fishes 
are also abundant. They are chiefly Cestracionts (or rather Cochliodonts, Owen, 
Geol. Mag., Feb. 1867). Their teeth (Cladodus, Diplodus, &c), or the hard 
* See an excellent general sketch of the chief tains,' vol. i. p. 89 et seq., pi. 1, and large woodcut 
Carboniferous deposits of Europe and America, showing the vertical succession, p. 111. 
with illustrations of the prevailing plants, in § This view of the two modes of formation of 
LyelPs Manual of Geology, 1851, 24th and 25th coal, which I have long advocated (see 'Eussia in 
Chapters; and 5th edit., 1855. See also Ansted's Europe,' loo. cit., and 'Siluria,' p. 280), has been 
' Ancient World,' and Prof. Morris's valuable adopted and well illustrated by Mr. D. Page in 
paper on Coals and Coal-plants in the Proc. Geol. his ' Advanced Text-book,' p. 154 ; and it is fully 
Assoc. vol. i. pp. 170 & 289. treated in the last edition of Mantell's 'Wonders 
t Having under consideration the enormous of Geology ' (1858). The inquirer who wishes to 
area omipied by the Carboniferous strata of study the British fossil plants of this period must 
North America, the late Professor H. D. Kogers consult the ' Fossil Flora' of Lindley and Hutton. 
endeavoured to reconcile the conflicting hypo- The same subject is still more developed by M. 
theses respecting the origin of coal. (See Trans- Adolphe Brongniart, who has given his views in 
actions American Assoc. Adv. of Science, 1842, an admirable sketch of the successive floras 
p. 433.) He ingeniously applies the opinions of imbedded in the crust of the earth. The publi- 
his brother, W. B. Eogers, and himself, respecting cations on the fossil Plants of Germany, by Corda, 
the influence of great paroxysmal earthquakes Goppert, Unger, and Geinitz, are productions of 
which affected the earth's crust in ancient periods, high merit. On comparing these works with those 
and suggests how the alternations of terrestrial on the coal-plants of America, described by 
and oceanic remains to which attention has been Lesquereux, Eogers, and others, we find that, like 
called in this Chapter, and particularly at pp. 296 the associated marine animals, the same species 
et seq., can best be explained.. inhabited very distant regions, or had a wide range 
I See ' Eussia in Europe and the Ural Moun- through many latitudes. 
