FLORA OF THE MIOCENE EPOCH. 755 



chites, Eiythrina, Bauhtnia, Mimosites, and Acacia — all plants having 

 their living representatives in warm climates ; Echitonium, Plumiera, 

 and other Apocynacese of equatorial regions, and Steinhauera, a Oin- 

 chonaceous genus ; mingled with species of Acer (Maple), Ulmus 

 (Elm), (fig. 936), Khamnus (Buckthorn), and Amentiferous forms, 

 such as Oomptonia (fig. 938), Myrica, Betula (Birch), Alnus (Alder), 

 Quercus (Oak), Fagus (Beech), Oarpinus (Hornbean), aU belonging to 

 temperate and cold climates. The statements as to the occurrence of 

 Pinus sylvestris and Betula alba among the Miocene fossils have not 

 been founded on complete data. It is by no means easy, even in the 

 present day, to distinguish fragments of dried specimens of Pinus 

 PumUio from those of P. sylvestris, and from a great many other 

 Pines. The difficulty is stUl greater in fossils. There are a very 

 small number of plants belonging to orders with gamopetalous corol- 

 las. As connected with the Miocene epoch, we may notice the leaf- 

 beds found at Ardtun, in the island of Mull, by the Duke of Argyll. 

 Above and below these beds basalt occurs, and there are peculiar tuff- 

 beds alternating with the leafy deposits. These tuflf-beds are either of 

 volcanic origin, or are a conglomerate stratified deposit, altered in a 

 metamorphic manner. The beds are associated with phalk and flints. 

 The leaves are those of plants allied to the Yew, Rhamnus, Maple, 

 Plane, and Alder, along with the fronds of a peculiar Pern, and the 

 stems of an Equisetum. The genera are Taxites or Taxodites, Rham- 

 nites, Platanites, Alnites, Filicites, and Equisetum. In the leaf-beds 

 at Bournemouth Mr. Wanklyn detected several ferns. One is called by 

 him Mertensites, and shows distinct venation and fructification. Fos- 

 silised wood was found in the Arctic Regions by Captain M'Olure. 

 At the- N.W. of Banks' Land he found trees with trunks 1 foot 7 

 inches in diameter. 



The Arctic fossil flora (Miocene), according to Heer, amounts to 

 162 species : Oryptogamia, 18 species, of which 9 are large ferns; 

 Phanerogamia, Coniferse, 31 ; Monocotyledons, 14 ; Dicotyledons, 99. 

 Among the Coniferse are — Pinus M'Clurii, Sequoia Langsdorfii, 

 Stembergii, and Couttsise, Taxodium dubium, Glyptostrobus Euro- 

 ■ pseus, Thuiopsis Europsea. Among leafy trees are — Fagus Deuca^ 

 lionis, Quercus Olafsoni, Platanus aceroides, willows, beeches, Acer, 

 Otopteryx, tulip-tree, walnuts. Magnolia Inglefieldi, Prunus Scottii, 

 Tilia Malmgreni, Corylus M'Quarrii, Alnus Kefersteinii, Daphnogene 

 Kannii probably one of the Lauracese ; and among Proteacese 1 Mac- 

 Olintoekia and Hakea. In Greenland are found species of Rhamnus, 

 Paliurus, Cornus, Ilex, Crataegus, Andromeda, Myrica, Ivy, and Vine. 

 From the flora of Spitzbergen, in the Miocene epoch, we may conclude 

 that under 79° N. lat. the mean temperature of the year was 41° 

 Fahr., while at the same epoch that of Switzerland was 69°'8 Fahr., 

 judging from the analogy of floras. It appears that for each degree of 



