Zoology and Botany. 329 



other of a part of the Under CliiF in the Isle of Wight, on the scale 

 of three feet to the mile. 



Mr Greenough mentioned a new mode of engraving medals late- 

 ly adopted in France, and which he conceived could be advanta- 

 geously employed in laying down the varieties of surface on maps. 

 — Mr Griffiths spoke of the great importance of models like Mr 

 Ibbotson's, as being so well calculated to display the geological 

 structure of a country. He suggested the importance of possessing 

 maps, both of outline and of features, and he alluded to the magni- 

 ficent map of Ireland, under the Ordnance Survey, the scale of 

 which, being six inches to a mile, enabled the geological observer 

 to trace the geological features with a facility before unknown. — It 

 was mentioned, that the new map of Austria was on a scale of 

 twenty-two inches to the mile, but this Mr Greenough considered 

 inconveniently large. — Mr Ibbotson stated, that models could be 

 easily multiplied by employing a metal mould, and using papier 

 machey or some preparation of caoutchouc ; and that they might be 

 dissected to exhibit the internal structure, and that the materials of 

 the strata themselves could be used as colouring matter. — Lord 

 Northampton and M. de la Beche gave their testimony of appro- 

 val. — Several gentlemen then spoke of the application of combina- 

 tions of letters to geological maps, to express the more minute geo- 

 logical phenomena ; but the general opinion was, that in geological 

 maps simplicity should, as much as possible, be preserved, and that 

 the best mode would be to have two maps of the same district, one 

 without names, for the geological map, and the other with the ne- 

 cessary writing. Maps of this kind had been given to the Geolo- 

 gical Society by the Archduke John of Austria. 



Section D. — Zoology and Botany. 



President — Professor Henslow. 



Vice-Presidents, — Rev. F. W. Hope, Dr J. Richardson, 



Professor Royle. 



Secretaries. — John Curtis, Esq., Professor Don, Dr Rilky, 



S. RooTSEY, Esq. 



Dr Richardson commenced the proceedings of the Section, by 

 reading the introductory portion of his report " On the Zoology of 

 North America." It did not appear probable that the progress of 

 colonization had, as yet, extinguished any one species of animal 

 from the country. The great similarity which existed between the 



