Geology and Physical Geography. 351 



entangled in the trap. The Duke also mentioned that the 

 first recorded visit to this spot was paid by Dr Johnson in 

 1773. In 1790 Mr Mills (Phil. Trans.) visited the ravine, 

 but did not notice the leaf-beds ; and subsequently Professor 

 Jameson and Dr Maculloch had coasted the island and de- 

 scribed its general geognosy. 



Professor Edward Forbes stated that the leaves were in a 

 very beautiful state of preservation, and belonged to species 

 of plane, alder, pine, equisetum, and some others. From the 

 presence of flints the deposit appeared to be newer than the 

 chalk, whilst in the latest tertiaries only vegetable remains of 

 a more boreal character were found. The leaves most re- 

 sembled some eocene specimens from Styria, figured by Dr 

 Unger, and those found in the (eocene) pipe-clay beds of the 

 Isle of Wight. Sir Jolm Richardson had also discovered 

 leaves of similar character at Mackenzie River, in Arctic 

 America. Fossil leaves and brown coal occur with layers 

 of trap in Iceland, an island composed chiefly of trap and 

 tertiary rocks. Professor Oldham mentioned the occuri'ence 

 of similar fossil vegetable remains associated with trap in 

 Ireland — but the merit of proving the tertiary nature of the 

 brown coal in the Island of Mull is due to the Duke of 

 Argyll. 



Sir R. I. Murchison exhibited and explained a " Geological 

 Sketch-map of Spain," communicated by M. E. De Verneuil. 



Professor Nicol, of Cork, read some observations on the 

 Promontory of Cantyre, in Argyllshire. This communica- 

 tion will be found at page 385. 



Mr R. Harkness read some observations on " the Repre- 

 sentatives of the Mountain Limestone as they occur in the 

 south and east of Dumfriesshire ," also on " the so-called 

 Fossil Footsteps in the variegated sandstone of Dumfries- 

 shire and Cheshire." 



Sir William Jardine exhibited specimens of these foot- 

 prints from Dumfriesshire. 



