750 FLORA OF THE CRETACEOUS EPOCH. 



lignite. This is the Dirt-bed, made up of black loam, wHch, at some 

 far distant period, was penetrated by the roots of trees, fragments of 

 whose stems are now found fossilised around it. These consist of an 

 assemblage of silicified stumps or stools of large trees, standing from 

 1-3 feet from the mould. Most of them are erect, some slightly in- 

 clined, and the roots remain attached to the earth in which they grew 

 (fig. 933). They appear to resemble Oycadacese. One of these is 

 Mantellia nidiformis (fig. 934). Carpolithes conica and Bucklandia 

 are fruits found in the OoKte. Some look upon them as fruits of palms. 

 The flora of the Wealden epoch is characterised in the south of 

 England by the abundance of the fern called Lonchopteris Mantellii, 

 and in Germany by the predominance of the Conifer denominated 

 Abietites Linkii, and the presence of Araucarites Pippingfordiensis, as 

 well as by numerous Oycadacese, such as species of Oycadites, Zamites, 

 Pterophyllum, Mantellia, Bucklandia, and a remarkable genus having 

 a fleshy fruit, and related to the ordinary Oycadacese as Taxus is to 

 the other Ooniferse, which has been described under the name of 

 Bennettites. In the Wealden at Brook Point, Isle of Wight, Oycads 

 have been detected allied to Encephalartos. Their fruit has been de- 

 scribed by Oarruthers as Oycadeostrobus. There are several species. 

 Mantell has found 40 or 50 fossil cones in the Wealden of England. 

 The remains are those of land plants. The Wealden fresh-water for- 

 mation terminates the reign of Gymnosperms. 



III.— ELOEA OF THE TERTIARY OR OAINOZOIC 

 PERIOD. 



{Includi7ig the Cretaceous Epoch.) 



Beongniaet's Reign of Angiospeems. 



This reign is characterised by the appearance of Angiospermous 

 Dicotyledons, plants which constitute more than three-fourths of the 

 present vegetable productions of the globe, and which appear to have 

 acquired the predominance from the commencement of the Tertiary 

 epoch. These plants, however, appear even at the beginning of the 

 Oretaceous period. In this reign, therefore, Brongniart includes the 

 upper secondary period, or the Oretaceous system, and aU the Tertiary 

 period. The Oretaceous may be considered as a sort of transition 

 period between the reign of Gymnosperms and Angiosperms. 



The Ceetaceotjs (chalk) period is characterised by the Gymno- 

 spermous almost equalling the Angiospermous Dicotyledons, and by the 

 existence of a considerable number of Oycadacese, which do not appear 

 in the Tertiary period. The genus Oredneria is one of the character- 



