XXVI . — Notice on the Geological Structure of a part of the Island 
of Madagascar , founded on a Collection transmitted to the Right 
Honourable the Earl Bathurst , by Governor Farquhar , in the year 
1819 ; with Observations on some Specimens from the Interior of 
New South Wales , collected during Mr, Oxley s Expedition to the 
River Macquarie , in the year 1818, and transmitted also to Earl 
Bathurst . 
By the Rev. Wm. BUCKLAND, b.d. f.r.s. 
MEMBER OF THE GEOLOGICAL SOCIETY, AND PROFESSOR OF MINERALOGY 
AND GEOLOGY IN THE UNIVERSITY OF OXFORD. 
Read May 5th, 1820. 
In the present imperfect state of geological knowledge, the smallest 
communications from those distant parts of the globe of which the 
composition is altogether unknown to us, become a valuable addi- 
tion to that stock of information which is gradually advancing the 
science of geology towards a point, at which it will be competent 
for us to form some well grounded theory as to the general structure 
of the Earth. 
MADAGASCAR. 
As our knowledge of the rocks which occur in the island of 
Madagascar is as yet very imperfect, I beg to lay before the Geolo- 
gical Society a few notices, which, by the favour of the noble 
Secretary of State for the Colonial Department, I have been enabled 
to extract from a series of specimens lately transmitted to his Lord- 
