BAGSHOT BEDS. 443 



sands and clays, with some coaly beds in the lower portion ; and 

 these appear to be the lowest of the Bovey Beds that have been 

 exposed. The clay of Kingsteignton is about 40 feet thick, it 

 rests on sand, and contains occasional sandy beds. The total 

 thickness of the Bovey deposit can only be conjectured as between 

 200 and 300 feet.^ 



The beds extend over a considerable tract of low-lying heath- 

 land bounded by ranges of hills. The physical and pala^ontological 

 evidence points to the deposit having been formed in a fresh-water 

 lake, which probably extended from Bovey Tracey to Kingskerswell, 

 without being open towards Teignmouth. The purely sedimentary 

 matter was evidently derived from the waste of the Greensand and 

 of the granitic rocks of Dartmoor; the clays being due to the 

 decomposition of the felspars, and the quartzose sands being the 

 relics of the harder material.^ (See Fig. 30, p. 194.) 



Numerous plant-remains have been found in the lignites, and 

 rarely in the clays. Attention was directed to these in 1857 and 

 subsequent years, by Dr. Oswald Heer and Mr. Pengelly. From 

 Dr. Heer's investigations it seems that the woods covering the 

 slopes which surrounded the old lake, consisted mainly of a huge 

 coniferous tree {Sequoia CoutssicB), a form resembling the Sequoia 

 ( Wellingtonid) giganiea of California. The leafy trees of most 

 frequent occurrence were the Cinnamoms and an Evergreen Oak 

 like those which now are seen in Mexico. Species of Evergreen 

 Fig were rarer. The trees of the ancient forest were evidently 

 festooned with Vines, and among other forms there were the prickly 

 Rotang-palm, the Laurel and numerous Ferns ; one species of 

 Pecopteris seems to have formed trees of imposing grandeur, while 

 on the surface of the lake were expanded leaves of the Water-lily.^ 

 Sir J. D. Hooker has observed that the lignite is mainly composed 

 of coniferous wood, and he noticed the occurrence of small pieces 

 of resin similar to the Highgate resin, which was probably secreted 

 by the coniferous trees.'' Excepting an Insect, Bupresiis, no remains 

 of animals have been obtained from the Bovey Tracey Beds. 



In 1879 Mr. J. Starkie Gardner expressed the opinion that the 

 Bovey Beds were not Miocene, but correspond in age with the 

 Bournemouth Leaf-beds, and his subsequent observations tend to 

 confirm this view.* 



^ De la Beche, Report Geol. Cornwall, etc., p. 248 ; see also Geol. Manual, 

 1831, p. 191. 



- See Prestvvich, Geologist, i. 113. 



^ W. Pengelly and Rev. O. Heer, On the Lignite Formation of Bovey Tracey, 

 Phil. Trans. Part II. 1862 (reprint 1863). 



* Q. J. xi. 566 ; see also Dr. J. G. Croker, Ibid. xxii. 354. 



* Q. J. XXXV. 227, xxxviii. 3 ; G. Mag. 1879, p. 152 ; P. Geol. Assoc, vi. 100. 



