62 Geological Society : Mr. Murchison's 



fossil shells characteristic of South Devon, the Boulonnais, and the 

 Eifel*. 



Carboniferous Limestone and Coal. — The lowest beds of the car- 

 boniferous system in Russia are, as stated in our first abstract (Phil. 

 Mag. S. 3. vol. xix. p. 493), sands and shale with thin seams of coal, 

 Stigmaria Jicoides, &c. The authors examined a considerable tract 

 occupied by these beds to the south of Tula and Kaluga, where many 

 additional natural outcrops have been discovered by Colonel Olivieri, 

 the mineral having the lignite or impure character of the beds of coal 

 described last year in a similar position in the Walda'i Hills. These 

 strata are, the authors conceive, of the same geological age as those 

 of the great productive coal-field of Berwickshire, which equally 

 underlies the mountain limestone. 



By their recent labours the authors have divided the carbonife- 

 rous limestone of Russia into three members. The lowest of these, 

 generally a dark-coloured rock, is characterized by the presence of 

 Productus giganteus and P. Waldaicus (near to P. anomala, Sowerby, 

 &c). The central mass is the well-known white limestone of Mos- 

 cow, containing Spirifer Mosquensis, S. resupinatus, S. glaber, the 

 Chcetetes radians, Euomphalus pentangulatus, and many other fossils, 

 some of which (such as Productus antiquatus, P. comoides) are found 

 also in the lower division. Beds of compact, yellow, magnesian 

 limestone occur in this central part of the carboniferous system, as 

 well as bands of red and greenish shale or marl, and thin beds of 

 pure siliceous flint graduating into ordinary limestone chert. 



The third calcareous division is one which is not seen in the Wal- 

 da'i or Moscow district, but which seems to surmount the before- 

 mentioned divisions on their eastern flank at Velikovo and Kosrof, 

 on the river Kliasma. Again, the lofty cliffs which occupy the 

 banks of the Volga between Stavropol and Samara are almost ex- 

 clusively composed of this member of the carboniferous limestone, 

 which is there made up of myriads of Fusulince (the fossil bodies 

 mentioned by Pallas as resembling grains of wheat), associated 

 with Euomphalus pentangulat us, Cyathophylli, &c. 



In a part of the coal region between the Dnieper and the Don, 

 the authors detected a band of this fusulina limestone, in the same 

 relative position which had been assigned to it in other parts of 

 Russia, namely, in the upper part of the calcareous strata. 



Carboniferous Region between the Dnieper and the Don, or Coal- 

 field of the Donetz. — Whilst the central member of the carbonife- 

 rous limestone of the northern parts of Russia (Moscow basin) con- 

 tains no coal, and the upper beds on the Volga are equally void of 

 it, rocks of the same age in the South of Russia, or on the banks 

 and in the neighbourhood of the river Donetz, are in parts emi- 

 nently productive of good bituminous as well as anthracitic coal. 

 Among the sections described, one from Karakuba, on the river 

 Kalmiuss, to the neighbourhood of Bachmuth, shows a regular suc- 

 cession, in ascending order, from beds of conglomerate and red 



* The large scales of Holoplychms Nobilissimus were found by the authors 

 at a locality called Kipet between Licbwia and Bielef. 



