666 FOURTH REPOltT 1834. 



a sufficient number of fossil sections been examined, it would 

 have been seen that in some of them the whole structure in the 

 longitudinal direction had been so much obscured that scai-cely a 

 trace even of the longitudinal partitions remained, and that 

 therefore the absence of discs could not be admitted as the 

 foundation of a new fossil genus. The presence or absence of 

 discs must often depend on the thickness of a section. In proof 

 of this Mr. Nicol has prepared a section of the present Crag- 

 leith tree, which when of the proper thickness showed the discs 

 very distinctly, but which now shows not a trace of them, in 

 consequence of tlie thickness being a little diminished. A source 

 of deception too often arises from the water absorbed in the pro- 

 cess of grinding. In some fossil woods, particularly those of a 

 whitish colour, the translucency is such, when the substance is 

 penetrated with water, that discs may be seen ; but when the 

 water is evaporated, a degree of opacity ensues which renders 

 them invisible. 



Mr. W. C. Trevelyan exhibited slices of fossil wood, from a 

 specimen which he had brought from Faroe, with drawings by 

 Mr. MacGillivray, who considers it an imdescribed species, and 

 proposes naming it Peniice Ferroensis. 



It occurs in the island of Suderoe, in the bed of clay asso- 

 ciated with coal, (all the other strata in that island belonging to 

 the trap family,) of which Mr. Trevelyan has given a short ac- 

 count in the Transactions of the Royal Society of Edinburgh 

 vol. ix. p. 461. 



Captain MacConnochie, Secretary to the Royal Geogra- 

 phical Society, gave an account of the origin and progress of 

 that Institution. He communicated some details relative to the 

 late expedition to the Niger, and to the expeditions which are 

 about to be sent out to the interior of Africa and to British 

 Guiana. 



Mr. Hall's model of a part of Derbyshire was exhibited. 



Mr. Saul exhibited drawings of the incisors and canine teeth 

 of the fossil Hippopotamus, from a gravel-pit near Huntingdon. 



Dr. BucKLAND laid before the Section a drawing, by Mrs. 

 Turner of Livei'pool, of a large fossil marine plant, found in the 

 riQW red sandstone of that neighbourhood in 1829. 



