300 ON THE LEAP-BEDS AND GRAVELS OE ARDTUN, ETC., IN MULL. 



Plate XV. 



Typical Eocene Plants from Limestone of Ardtun ; natural size. 



Fig. 1. Bcehmeria antiqua, sp. nov. (p. 291). 



2. Ovate, serrate leaf, undetermined. 



3. Corylites Macquarrii, Forbes, sp. 



Plate XVI. 



Typical Eocene Plants from Limestone of Ardtun ; natural size. 



Fig. 1. Ovate, serrate leaf, undetermined. 



2, 3, 5. Evergreen leaves, like those of MyrtacecB. 



4. Betula-like leaf. 



Discussion. 



Mr. Batjeilxlan, as Chairman, remarked upon the great interest 

 attaching to the study of these deposits, upon which the Author 

 had brought forward a most valuable series of observations and illus- 

 trations. 



The President also bore testimony to the value of Mr. Gardner's 

 collections. Referring to the points upon which the Author differed 

 from himself in opinion, he said that when he visited the locality 

 he was impressed with the fact that Macculloch had correctly 

 described what existed then. He thought that the Author was 

 mistaken in the significance he attached to " rubble-chalk." liubble- 

 chalk was not chalk transported, but broken up in situ. He con- 

 sidered that the presence of lignite in the unfossiliferous sand- 

 stones lying above the Upper Greensand was indicative of estuarine 

 conditions. 



Mr. Carruthers remarked upon the extreme value of the col- 

 lections obtained by Mr. Gardner, but said that as the specimens 

 had not yet been worked out, he could not venture to pronounce any 

 opinion upon the evidence which they furnished. 



Mr. G. F. Haeeis remarked upon the age of the deposits, which 

 he understood Mr. Gardner paralleled with the Heersian beds of 

 Belgium ; and if this were so, the Mull beds in question would not 

 he older than the Thanet of this country. 



The Author, in reply, referred particularly to the small thick- 

 ness of Chalk occurring in Mull, and stated that in the case of the 

 " rubble-chalk," its being in situ or not seemed to him to be an 

 open question. He would not deny that the Greensand deposits 

 might be estuarine, but at the same time he thought that Macculloch 

 had assigned this character to them upon hearsay evidence. 



