206 
M. D. Zalessky. 
THE NATURAL HISTORY OF A SIBERIAN COAL: 
An Abstract by Professor Zalessky (Petrograd) 
of his Original Paper. 
Histoikk naturellk d’un Charbon (Russian and French), by M. D. 
Zalessky. Mem. Comit6 geol., nouvelle ser., livr. 139. Petrograd. (4to, pp. 74, 
pis. XIII). Price 4 R. (8s.). 
TMHIS work represents the detailed description of a coal and the 
fossil organisms discovered in it. Some pieces of this coal 
were picked up by the geologists A. A. Sniatkov and V. C. Pancratov 
on the bank of the river Tam (Siberia), where it is entered by the 
tributary Spuskovoj, and the seam of this coal, hitherto not yet 
found, should he subordinate to rocks of the upper Kemmern series 
of a common section of the palaeozoic deposits of the Kuznetsk 
basin. The readers of the Russian Geological Messenger are 
acquainted with this kind of coal, named Fornite, from a previous 
report by M. D. Zalessky and A. A. Sniatkov in this review, No. 4, 
vol. I, 1915. The first chapter is an introduction into investigation 
and before entering the subject, the formation of coal is touched on 
in general, the interesting new fact is cited of a discovery of calcareous 
concretions in the Brusnitzin Coal-seam of Kolchugino coal-mine, 
in the Kuznetsk basin. These portions of the mother substance of 
the coal are constituted of a mass of decayed leaves of Nlesopitys 
Ichihcitcheffi among which a great many scarcely deformed, 
decorticated branches of the same plant of various thickness are so 
well-preserved, as to lead the author to believe that the coal-seam 
of such a constitution may have resulted from accumulation of 
vegetable remains in situ. The mass of leaves he compares with 
forest-litter, discriminating, however, the circumstance that this 
litter was formed in a swampy forest, and the decay of the leaves 
and branches took place under water and not in the open air. 
The drift of vegetable remains is admitted by him only within 
swamp precincts. Making reference to sapropel coals he touches 
on another interesting fact, namely the accumulation of the green 
Alga Botvyococcus Braunii, in a great mass, on the shore as well as 
on the bottom of the Ala-Kul, a bay of the lake Balkhash, giving 
the clue to the solution of the origin of Bogheads and Torbanites 
constituted, in the opinion of some authors, from the accumulation 
of fossil Algae. 
The second chapter deals with the nature of the new coal, to 
which the author gives the name sapromyxite , instead of the former 
