Geological Society. 381 



Between the former and Elizabeth Town, a limestone full of 

 shells is found, probably of the oolite series, and the same 

 rock occurs near George Town on an island in the Tamar. 

 In the middle of the island, at Bagdad, a rock which answers 

 to the description of the millstone grit, and salt, is found on 

 the river Macquarrie. To the east and the west of the in- 

 habited tract between the two towns, high mountains and ele- 

 vated primitive ridges are alone discoverable ; so that the island 

 probably contains little other fertile soil to tempt future emi- 

 gration when this space shall have been peopled, which is not 

 the case in New South Wales. 



A letter was read On a Section obtained in sinking a Well 

 at Streatham ; by Mr. I. S. Yeats. Communicated by G. H. 

 Brown, Esq. 



A well having been sunk at Streatham to the depth of 285 

 feet, the greatest depth which has been pierced in that part of 

 the country, the following section was exhibited. From the 

 depth of 2 feet to 29 feet, stiff reddish brown clay ; from 

 thence to 35 feet, clays with septaria ; from thence to the 

 depth of 180 feet, blue clay, in which, in from 70 to 100 feet, 

 were found various shells and fragments of bituminous wood 

 with iron pyrites ; from 200 feet to the depth of 230 feet, blue 

 clay, sometimes sandy, in which numerous shells and bitu- 

 minous wood occurred ; at 230 feet, round black pebbles of 

 flint like those of Blackheath were found, this appearing to 

 be the point of junction between the London and plastic clays ; 

 next a bed of sand, and afterwards various coloured clays 

 were pierced, at the depth of 270 feet ; and continuing to 

 285 feet, sand and sandy clays occur, the greater part of 

 which is full of green earth exactly resembling that of the 

 oyster bed at Reading. The paper was accompanied by spe- 

 cimens of each of these strata. 



A letter was read from Alexander Gordon, Esq., to D. Gor- 

 don, Esq. of Abergeldie, describing three successive forests 

 of fir imbedded in a peat moss, accompanied by specimens. 



The moss of Auldguissack in Aberdeenshire, Scotland, 

 presents an inclined plane of rather uneven surface, and va- 

 ries in depth from 18 inches to 10 feet from the lower part of 

 the hill to the river. 



Upon digging up the ground in two different parts of the 

 moss, large roots of Scotch fir-trees were found about one 

 foot below the ordinary average level of the moss. Below 

 the bottoms of these roots there is a stratum of about a foot 

 and a half of moss, below which other roots or trunks ap- 

 peared ; and on digging still further down (about 6 or 7 feet 

 below the ordinary level of the moss) a third set of roots and 

 truncated stems of trees were discovered, 



It 



