Section of Geology and Geography. 487 



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 Mea- 

 sures 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 t/ie 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 aeras, that of Devon extending from Bideford to 

 South Molton, being a true ' transition' coal, imbedded in ' 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. 



On the Survey of the Mersey and the Dee. By Captain Henry 

 Mangles Denham, R. iV., Resident Marine Surveyor of the Port 

 of Liverpool. 



Captain Denham exhibited his trigonometrical survey of the 

 Mersey and Dee, including the extensive sand-banks and channels 

 of Liverpool bay, which, being delineated on the scale of four inches 



* See our present volume, p. 81 et ieq., p. 353 — 354, and also p. 464, 

 et seq. of our present number. — Edit. 



