229 
Jurian to the middle grauwacke, and the Cambrian system to the 
lower. 
In this threefold distribution of the vast series of strata which 
have hitherto been indiscriminately designated by the common term 
grauwacke, we are, as it were, extending the progressive operations 
of a general inclosure act over the great common field of geology ; 
we propose a division, founded on measurements, surveys, and the 
study of organic remains, analogous to that. of the secondary strata, 
from the chalk downwards to the coal formation, established by 
William Smith, and to the separations of the once undivided ter- 
ritory of the great tertiary system, effected by Cuvier and Brongniart, 
Desnoyers, Lyell, and Deshayes. 
To the uninitiated in geology, rectifications in the distribution 
of strata upon so large a scale may seem calculated to shake confi- 
dence in all the conclusions of our science ; but a contrary inference 
will be drawn by those who know that these corrections have never 
been applied to conclusions established on the sure foundation of 
organic remains, but to those rocks only of which the arrangement 
had been founded on the uncertain character of mineral compo- 
sition. 
COAL FORMATION. 
The Society has received from Professor Ansted a paper on the 
Carboniferous and Transition Rocks of Bohemia, a country which 
he visited last summer, directing especial attention to the district 
between Prague, Luditz and Pilsen, which he has illustrated by sec- 
tions made from personal observation. Above the fundamental 
granite and gneiss he found extensive deposits of grauwacke, on 
which lie, in unconformable superposition, disconnected patches of 
the coal formation. The age of this coal is well known, from the 
fossil Flora of Count Sternberg, who resided in the midst of it near 
Swina, to be identical with that of the great Coal formation of En- 
gland. Mr. Ansted gives information also as to the action of trap 
rocks in producing disturbances of the strata in this district ; and re- 
specting dislocations, by which the grauwacke is several times placed 
on a level with the coal measures, whilst in some cases the strata are 
inverted and the coal measures laid beneath the grauwacke. 
We have received an interesting communication from Mr. Hawk- 
shaw respecting a remarkable disclosure made in the Bolton Railway, 
