Part II. Sect. iv. § 2.| CARBONIFEROUS. 749 
contains limestones, full of Carboniferous Limestone fossils and a few poor 
seams of coal. In the south of the empire the coal-field of the Donetz, 
covering an area of 11,000 square miles, contains 60 seams of coal, of 
which 44, having a united thickness of 114 feet, are workable. Again, 
on the flanks of the Ural Mountains, the Carboniferous Limestone series 
has been upturned and contains some workable coal-seams.. It would 
appear, therefore, that this particular type of mingled marine and 
terrestrial strata of Carboniferous age, occupies a vast expanse under 
later formations in the east of Europe. 
Asia, Australia.—The Carboniferous system is extensively de- 
veloped in Asia. Over the great plain of China, an area of Coal- 
measures 30,000 square miles in extent les quite flat upon a mass of 
. limestone forming an escarpment 2000 to 3000 feet high, and the coal- 
seams (30 feet thick) are said to be horizontal for 200 miles. In 
Australia, important tracts of true Carboniferous rocks with coal-seams 
range down the eastern colonies and are specially developed in New 
South Wales, where the coals are numerous, and from 8 to 30 feet 
thick. Among the plants of these strata are some well-known European 
forms, as Alethopteris lonchitica, Bornia radiata, Calamites varians, Glosso- 
pteris browniana, Lepidodendron nothum, L. rimosum, and L. veltheimianum. 
The fauna includes the wide-spread and characteristic Carboniferous 
Limestone forms Lithostrotion basaltiforme, L. wrregulare, Fenestella plebeia, 
Athyris Royssvi, Orthis Michelini, O. resupinata, Productus aculeatus, P. cora, 
P. longispinus, P. punctatus, P. semireticulatus, and many more.! 
North America.—Rocks corresponding in geological position and 
‘the general aspect of their organic contents with the Carboniferous 
system of Europe are said to cover an area of more than 200,000 
square miles in the United States and British North America. The 
following table shows the subdivisions which have been established 
among them : 
(Coal-measures,—a series of sandstones, shales, ironstones, coals, &c., 
varying from 100 feet in the interior continental area to 4000 feet in 
Pennsylvania, and more than 8000 feet in Nova Scotia. The plant re- 
mains include forms of Lepidodendron, Sigillaria, Stigmaria, Calamites, 
ferns, and coniferous leaves and fruits. ‘The animal forms embrace in 
the marine bands species of Spirifera, Productus, Bellerophon, Nautilus, 
&e. Among the shales and carbonaceous beds numerous traces of insect 
life have been obtained, comprising species related to the may-fly and 
cockroach. Spiders, scorpions, centipedes, limuloid crabs, and land snails 
like the modern Pupa have also been met with. The fish remains com- 
prise teeth and ichthyodorulites of placoid genera, and a number of 
ganoids (Eurylepis, Celacanthus, Megalichthys, Rhizodus, &e.). Several 
labyrinthodonts occur, and true reptiles are represented by one saurian 
genus found in Nova Scotia, the Hosaurus. 
In the western Territories the Upper Carboniferous rocks consist of a 
massive group of limestone 2000 feet thick, resting on Lower Carbon- 
iferous (“‘ Weber Quartzite” of King) estimated at 6000 to 10,000 feet, 
but with no coals. 
Millstone Grit,—a group of arenaceous and sometimes conglomeratic strata, 
with occasional coal-seams, only 25 feet thick in some parts of New York, 
| but swelling out to 1500 feet in Pennsylvania. 
Carboniferous. 
1 Richthofen’s “ China,” vol. ii. W. B. Clarke, “ Fossiliferous Formations of N, §, 
Wales,” 1875, R. Etheridge, Jun., “ Catalogue of Australian Fossils,” 1878. 
