FLORAS OF SHEPPEY AND ALUM BAY. 475 



are all present, with Cinchonidium, Strychnos, and Solanites. The 

 Ebony is represented by species of Diospyros. Magnolia, Lotos, and 

 Victoria Water Lilies, Melons, representatives of the Mallows, Soap- 

 worts, Eucalyptus, Cotoneaster, Almond, Plum, and a multitude of 

 leguminous plants, do not exhaust the list. When we compare this 

 flora with that of the Alum Bay clays, 25 genera are found to be in 

 common. The newer deposit is the richer of the two, including 

 representatives of 116 genera, and 274 species. Among the types in 

 common are Conifer, Sequoia, the Palm, Sabal, Oak, Convolvulus, 

 Walnut, Laurel, Cinchonidium, Magnolia, Lotus, Maple, Plum, 

 Almond, and the Australian Gum-tree Eucalyptus. 



The types characteristic of the Alum Bay beds are more numer- 

 ous Oaks, Elms, the Beech, many species of Ficus, Santalum, which 

 yields the sandal wood, and Nyssa, the American sour gum tree. 

 Laurels abound, the Daphne and Aristolochia occur ; the Oleacese have 

 representatives of the Olive and Ash, and the Sapotacese are more 

 numerous than in Sheppey. The Verbena group, Convolvulus, Heaths, 

 Aralia, Saxifrages, white Water-lily, Spindlewood, Buckthorn and 

 Vines, Sumach, Pistacio, and many other interesting types are found, 

 besides numerous leguminous forms, among which Cassia is particu- 

 larly abundant. The Acacia and Mimosites are both represented. 1 



This flora has much in common with the Middle Tertiary of Green- 

 land, Iceland, Spitzbergen, and Central Europe. And at the present 

 day, in passing from the Mediterranean to the Levant, Caucasus, 

 and Persia, we find representatives of Miocene genera such as 

 ChamEerops, Platanus, Liquidambar, Pterocarya, Juglaris, &c. Other 

 Middle Tertiary genera may be traced through the Himalayas, and 

 towards China ; and the Tulip tree. Liriodendron, common in the 

 Miocene time, is found in Central China as well as in North 

 America. Some Miocene genera, like Astragalus, are common to 

 both continents. Others, like Eupatorium, Aster, Flox, Solanum, 

 are more numerous at the present day in America than in 

 Eastern Asia, and diminish westward, reaching Europe in single 

 species. 



Coal. Wherever vegetation has accumulated in swampy localities 

 necessary for its preservation, coal has been formed, and hence coal is 

 of every geological age. Its formation in the Carboniferous period, 

 and generally, was analogous to the growth of peat. Intercepted 

 drainage killed the forest trees in districts experiencing a temperate 

 climate, and, as in the English fens or Irish bogs, the stumps of 

 forest trees are found beneath the vegetable growth, which was itself 

 a soil for plants of many kinds, now imperfectly preserved. Spores 

 of coniferous trees furnished bituminous bands. Peat, like coal, 

 alternates with beds of clay. 2 



1 Ettingshausen : Proc. Roy. Soc., vol. xxix. p. 388, and vol. xxx. p. 228. 



2 Geological Magazine, vol. iii., Nov. 1866. 



