CHAP, vii.] DISTRIBUTION OF PLANTS. 199 



belongs the London clay, which contains many beauti- 

 fully-preserved fossils. Sheppey is also a noted locality 

 for fossils, the fruits of palms being common, accom- 

 panied by the remains of turtles and nautilus shells, etc. 

 The Bagshot Beds near Bournemouth, and Alum Bay in 

 the Isle of Wight, have seams of clay that are rich in 

 fossil leaves. 



During Miocene times the British Isles appear to 

 to have been for the most part dry land, the Bovey 

 Tracey Beds occurring between Exeter and Teignmouth, 

 however, belong to this period, and contain the remains 

 of numerous plants, mostly leaves, the commonest being 

 that of a great coniferous tree, Sequoia Couttsice, which 

 appears to be closely allied to the gigantic Wellingtonia 

 Gigantea of California. Leaves of species of vine, 

 cinnamon, and fig are also common, pointing to a con- 

 tinuation of the warm climate of the previous period. 

 The flora that clothed the European Alps during this 

 period was not unlike the vegetation of the forests of 

 India and Australia at the present time. During the 

 latter portion of the Miocene age there are evidences of 

 a cooling down of the climate, the characteristic vege- 

 tation consisting of beeches, elms, poplars, hornbeams, 

 etc. 



During the Pliocene age the flora shows a gradual 

 decrease of temperature, the tropical types of vegetation 

 of Eocene and Miocene times gradually retreating south- 

 wards, their place being taken by trees that still exist 

 here at present, as oaks, poplars, willows, alders, etc., 

 mixed, however, with forms that now occur in warmer 

 climates, as bamboos, sarsaparillas, magnolias, and figs. 

 In British rocks belonging to this period, which are 



