NATURAL HISTORY SOCIETY OF GLASGOW. 23 



This composition is very similar to that of many shales and beds 

 of consolidated mud. The matter burnt off at 500° seems to be 

 the organic particles of the leaves still remaining in the matrix. 



After referring to the reasons for assigning these leaf beds to 

 the Miocene period, the writer concluded with some remarks on 

 the recent researches into the Miocene flora of the Polar regions, 

 and their connection, in point of time, with the Mull flora. 



A Plane tree, Platanus aceroides, probably identical with the 

 P. hebridicus of Mull, appears to have spread over North Canada 

 and Greenland, and extended to Iceland, and even to the ice-fiords 

 of Spitzbergen, while Hazel and Alder seem to have been common 

 trees all over the north, along with other species which have been 

 found in these leaf beds. Sequoia would a|)pear to have been the 

 predominant genus, not less than seven species having been 

 recognised; while only two have come down to the present day, 

 both of which are living in California. Sequoia Langsdorfii was 

 the chief tree in North Greenland, but grew also in Canada, 

 Vancouver's Island, Switzerland, and Italy. It can only be 

 distinguished from the existing S. sempervirens by the larger 

 size of its cones. Sequoia Sternbergii again prevailed in Iceland, 

 and approached very close to the existing S. gigantea, the 

 Wellingtonia or mammoth tree of California. Such a flora as 

 existed in this Miocene period, in regions now covered with snow 

 and ice, clearly shows that a considerable diminution of tempera- 

 ture must have taken place, though it may not have been so much 

 as has been imagined. 



Dr Grieve also exhibited, with remarks, a specimen of a sponge, 

 Halycliondria suherea, completely investing a Fusus shell in which 

 a Pagurus Icevis had taken up its abode, also a specimen of an 

 Entomostracan, Nehalia bijjes, both from Rothesay, and a series 

 of Amphipoda and Isopoda from Gourock, of which the following 

 is a list : — 



AMPHIPODA. 



Anonyx ampulla. 



denticulatus. 



Dexamine spinosa. 

 Microdeutopus vetsiculatus. 

 Protomedeia Whitei. 

 Erystheus erythroptlialmus. 

 Gammarus marinus. 



