TRANSACTIONS OF THE SECTIONS. 
63 
the limits of error in the application of Mr. Lyell’s test of the age 
of tertiary formations by the numerical relations of the species of 
fossils which they contain to recent forms. It appeared to Pro¬ 
fessor Phillips that these limits were wide, and that a method of 
such power and value must not be applied without great caution. 
A letter from Charles Lyell, F.R.S., Pres. G.S. to Professor 
Sedgwick, on the fossil shells of the Suffolk Crag, considered in 
two divisions, according to the views of Mr. Charlesworth, was 
read to the meeting. 
Account of Fossil Trees in the attitude of growth in the Coal Measures 
near Glasgow. By James Smith, F.R.S., of Jordan Hill. 
The trees in question were discovered at Balgray Quarry, imme¬ 
diately adjoining the aqueduct over the Kelvin, about three miles to 
the north of the city of Glasgow. 
The quarry abounds in the usual coal plants, laid horizontally; 
in one part of it a number of trees were found standing in an up¬ 
right position, throwing their roots out in all directions, to all ap¬ 
pearance in the attitude in which they grew, without fracture or 
disturbance. They rest upon, and are imbedded in, strata of sand¬ 
stone, which are horizontal, or nearly so. The stems terminate about 
two feet above the roots, the superincumbent bed of stone passing 
over them as if they had been cut off. They are about two feet 
and a half in diameter, and are placed as near each other as trees 
of the same size could grow. No internal structure was observed., 
but from the ramification of the roots and of fragments of branches 
found near them, and the external appearance of the bark, which is 
channeled or furrowed, the author presumes that they were dicoty¬ 
ledonous. 
On certain Fossil Plants from the opposite Shores of the Bristol 
Channel. By the Rev. David Williams, F.G.S. 
These fossils were collected by the author in Devonshire and Pem¬ 
brokeshire, from shales alternating with anthracitic coal (culm ); 
and he states that, after a careful examination, he was led to con¬ 
clude positively that the strata of the true localities belong to very 
different geological eeras, that of Devon extending from Bideford to 
South Molton, being a true 4 transition’ coal, imbedded in 4 transi¬ 
tion’ schists, and that of Pembrokeshire and Caermarthenshire be¬ 
longing to the coal-measures above the mountain limestone. On the 
similarity of these plants found in formations of such different age, 
the author founds objections to the hypothesis of secular refrigera¬ 
tion ; and the speculation that the atmosphere in early geological 
periods was charged with a greater quantity of carbonic acid gas; 
and proposes the case as at least an exception to the law, that strata 
may be identified by their imbedded organic remains. 
