Geological Society. 389 
one point near the base of the largest tree, and though indistinct, his 
practised eye recognised them to be those of a Sigillaria. He de- 
tected also in some parts, on the ribs of the same tree, the fine wavy 
lines so often visible on decorticated specimens of that family. In 
describing the second tree, he alludes to a deep wedge-shaped rift 
on the south-east side, which had been coated with coal, and is 
strongly marked with wavy lines, like those on the surface of the al- 
burnum of a gnarled oak. On the fifth tree, he discovered a longi- 
tudinal concavity on the north side, and he states that it resembles 
the impression which would be left in a dicotyledonous tree, by the 
pressure of a parasitic plant. The characters of the roots are also 
detailed at considerable length, particularly their mode of bifurcation, 
and position with respect to the horizon. 
From a careful consideration of the phenomena presented by the 
fossils, Mr. Bowman is convinced that they stand where they origin- 
ally flourished; that they were not succulent, but dicotyledonous, 
hard-wooded forest trees; and that their gigantic roots were mani- 
festly adapted for taking firm hold of the soil, and in conjunction 
with the swollen base of the trunks to support a solid tree of large 
dimensions with a spreading top. 
Towards the close of 1838, in forming the railway tunnel at Clay- 
cross, five miles south of Chesterfield, a number of fossil trees were 
found, standing at. right angles to the plane of the strata. The tunnel 
passes through the middle portion of the Derbyshire coal measures, 
which there dip about 8° to a little north of east. The bases of the 
trees rested upon a seam of coal fifteen inches thick. ‘The exterior 
of the stems consisted of a thin film of bright coal, furrowed and 
marked like the Sigillaria reniformis ; and the interior consisted of a 
fine-grained sandstone. Mr. Conway, who supplied Mr. Bowman 
with an account of the discovery, infers, from the information which 
he obtained, that there must have been at least forty trees found, 
and judging by the area excavated, he is of opinion that they could 
not have stood more than three or four feet apart. There were no 
traces of roots, the stems disappearing at the point of contact with 
the coal. Several specimens of Stigmaria ficoides were also noticed 
by Mr. Conway, lying horizontally and about three feet in length. 
With reference to fossil trees in general, and especially to those 
near Manchester, Mr. Bowman proceeds to show still further; 1st, 
that they were solid, hard- wooded, timber trees, in opposition to the 
common opinion that they were soft or hollow ; 2nd, that they ori- 
ginally grew and died where they have been found, and consequently 
were not drifted from distant lands ; and, 3rd, that they became hol- 
low, by the decay of their wood, from natural causes, similar to those 
still in operation in tropical climates, and were afterwards filled with 
inorganic matter, precipitated from water. 
1. In stating his reasons for believing that the coal measures’ casts 
were solid timber trees, Mr. Bowman alludes to the rifting of the 
bark of modern forest trees, in consequence of the expansion caused 
by the annual addition of a layer of wood between the bark and the 
alburnum ; and to the thickening or swelling of the base of the trunk 
