140 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



is not that of a true Dicotyledon, it must still have been the interior 

 cellular portion of an arborescent plant like Lepidodendron, the 

 supposed bark being the vascular system or sheath surrounding the 

 pith, which has adhered during decay to the medullary column, and 

 sometimes become changed into coal. Examples of this condition 

 were exhibited. 



2. On the Tertiary Formations of the Isle of Man. By the 

 Rev. J. G. Gumming, M.A. 



[This memoir forms the second part of the author's communica- 

 tion on the Geology of the Isle of Man. It is unavoidably post- 

 poned till the next number of the Journal.] 



