Dartmoor, and their associated sands and clays, were formed in a lake at least fifty fathoms deep, and spread over an area of about twenty-four square miles, fed by the rivers Teign and Bovey, which did not then unite as they do now. In other respects, the leading features of the district were then nearly as they are now, and the heights of Dartmoor and the neighbouring hills commanded the lake very much as they stand at present over the plains of Bovey. The woods then growing on the sides of the lake and on the banks of the rivers were to a large extent composed of a huge conifer (Sequoia Couttsiæ), analogous to the mammoth tree (Sequoia (Wellingtonia) gigantea) of California, and in general appearance identical; its leaves, however, were shorter, and its cones smaller. Cinnamon trees (Cinnamomum lanceolatum and C Scheuchzeri) were abundant, and an evergreen oak (Quercus Lyelli), somewhat like those now living in Mexico. There were evergreen figs also, and custard apples (Anona), and a species belonging to the genus Gardenia. Vines leapt from tree to tree, and the prickly rattan-palm (Palmacites dæmonorops) was to be seen among the dark green foliage of the Dryandroides, which calls to mind the banksias of Australia. Gum trees were also there; and the spindle trees, now found in the warmer regions of Europe, North America, Asia, and Africa, are represented by a species of Celastrus. In the shade throve numerous ferns, one of which (Pecopteris lignitum) seems to have formed "trees of imposing grandeur," and the undergrowth was largely composed of various species of the North American genus Nyssa. On the margin of the lake clusters of water-lilies raised their beautiful blossoms and dark-green leaves, shedding
