132 
“marls, 146 feet in thickness. Thus the central portion of the 
“ Carboniferous series, 1,438 feet in depth at Bristol, becomes 
“480 feet at Dean Forest.” The depth of 480 and 165 feet 
are to be seen in the section, but it is not clear where we are 
to find the “146 feet,” as the first division of the section is 194 
feet nearly, or 48 feet in excess of the number stated. There 
does not therefore appear to be an exact agreement between 
the numbers in the section and the description appended to it. 
I apprehend the former has to be taken as being correct. 
The late Mr David Mushet, whose memory is much revered 
in the Forest of Dean, published a section of that district in 
the “Transactions of the Geological Society of London,” as far 
back as 1824, but he had not then the means at hand to con- 
struct an accurate section in all its details. It is as follows :— 
SECTION No. 2 
ey) 
Q 
1— Porcelain limestone 
2— Dark grey limestone . 
3--Ball limestone in clay matrix.. 
Upper lime- | 4—Small blue beds ; 
stone shale | 5—Grayish blue limestone, with 
purple joints 
6 —White limestone 
Limestone 7—Iron-ore and marl, from 10 to 
8—Great white cliff bed of lime- 
stone . Se 
9—Yellow clay limestone Be 
10—Great blue limestone oolitic to 
the N.W. of Coleford, with 
clay ... 8 0 
11—Sparry limestone oolitic near 
St. Briavels, and slightly so 
near Coleford : all 
12—Brownish red iron-ore, ‘Swan-) 
Pool or Cherry Orchard 
limestone a 
Lower lime- | 13--Beds of brownish red ‘marl ... 
stone shale | 14—Straw coloured shale ... 
me COP o> 
76 0 
oo 
— 
, an) ooo Or 
CoO coo ooooLs 
me Om 
Limestone 
The late Mr Atkinson also published a section of the Forest 
in 1851, and seems to have taken the thickness of the Carboni- 
ferous Limestone at about 710 feet. There is no agreement 
between the authorities quoted, but the data employed may not 
have been obtained from the same places in the district, and 
