296 



MR. J. S. GARDNER ON THE LEAF-BEDS 



have been collected from more than forty fresh localities within the 

 Arctic Circle, some of which are obviously of much later age, and 

 which we need not now take into account. 



The most conspicuous of the leaves at Ardtun, both on account of 

 its size and abundance, is the Platanites hebridicus, Forbes, identi- 

 fied by Heer*, first with Platanus aceroides, Goppert, of Schrotz- 

 burg, and subsequently with P. Guillelmce, Goppert, of Schossnitz f . 

 The materials for comparison were the two figures in the Journal of 

 this Society, neither of which show base, apex, or margin, and some 

 hardly more perfect specimens from Greenland, the fragments of 

 different leaves brought home having, it is stated, to be pieced to- 

 gether to get an idea of the leaf. The fine series of perfect speci- 

 mens which we now possess shows that Forbes's species differs in 

 nearly all its details, and is a much larger form than any of the 

 Miocene species of Platanus of either Europe or America, and 

 greatly resembles the Cretaceous Credneria, as observed, indeed, by 

 Heer, as well as some of the Sezanne leaves of Paleocene age. 



Casianea Ungeri, Heer, Fagus castanece folia, Unger, from the 

 Miocene of Leoben and Wartzberg, in Styria, &c, and of the 

 American Miocene, is a handsome species and probably a true Cos- 

 tanea ; but the cutting of the leaf in the Greenland specimens identified 

 with it is different, and the fruits X which are cited in support of the 

 determination are far more like the similar bodies from Ballypalady 

 than like chestnuts. Fagus macrophylla, Unger, is identified as a 

 Greenland fossil on an indistinct fragment of a leaf which differs in no 

 respect from the above ; whilst the leaf named Quercus furcinervis, 

 Rossm., is probably only another specimen of the same species, and 

 differs widely from any leaves of the Swiss Molasse or the American 

 Miocene bearing that name. The supposed Planera Ungeri, Ett., of 

 Greenland, is represented by a single specimen, which might well be 

 a distorted form of the same so-called Castanea ; and neither its 

 form, cutting, nor venation justify its association with the well- 

 marked Miocene form, so prevalent in the Molasse &c. of Switzer- 

 land, Germany, and Italy. 



The supposed Carpinus grandis, Unger, of Greenland and Mull, 

 is a leaf with different cutting, and veins much wider apart and 

 more forked than the Swiss or American forms. 



Quercus Drymeia, Unger, is a species well known from the Middle 

 Eocene to the Oligocene ; but there is nothing in two fragments from 

 Greenland to justify their reference to it. 



The same remarks apply to Salioe varians, Gopp., and to the 

 single imperfect and characterless leaf identified with Rhamnus 

 Rossm dssleri. 



The specimens ascribed to Juglans acuminata, A. Br., are im- 

 perfect leaves without decided characters, which do not resemble in 

 any definite way the splendid specimens figured by Heer under that 



* Flor. Tert. Helv. vol. ii. p. 71. 



t Goppert, 4 Die Tert. Flora von Schossnitz in Schlesien,' 1855. p. 21. 

 \ Flor. Arct. vol. ii. pi. xlv. figs. 2-2 b. 



