364 FOSSIL CONIFERS. 



in the structure of their wood, whereby the smallest frag- 

 ment may be identified. 



Recent microscopic examinations of fossil woods have 

 led to the recognition of an internal structure, resembling 

 that of existing Coniferse, in the trunks of large trees, both 

 in the Carboniferous series,* and throughout the Secondary 

 formations ;f and M. Ad. Brongniart has enumerated twenty 

 species of fossil Coniferas in strata of the Tertiary series. 

 Many of these last approach more closely to existing Genera 

 than those in the Secondary strata, and some are referable 

 1o them. 



It has been farther shown by Nicol, (Edin. New Phil. 

 Journal, January, 1834) that some of the most ancient fossil 

 Coniferse may be referred to the existing genus Pinus, and 

 others to that of Araucaria; the latter of these compre- 

 hends some of the tallest among Hving trees, (See PI. 1, Fig. 



The recognition of tlicse peculiar characters in the structure of the 

 stem, is especially important to the Geological Botanist, because the stems 

 of plants are often the only parts which are found preserved in a fossil 

 state, 



* The occurrence of large coniferous trees in strata of the great Coal 

 formation, was first announced in Mr. Witham's Fossil Vegetables, 1831. 

 It was here stated that the higher and more complex organizations of Coni- 

 ferse exists in the Coal fields of Edinburgh and Newcastle, in strata which 

 till lately have been supposed to contain only the simpler forms of vegetable 

 structure. 



t In the lower region of the Secondary strata, M. Ad. Brongniart has 

 enumerated, among the fossil plants of the New red sand-stone of the 

 Vosges, four species of Voltzia, a new genus of Coniferse, having near 

 affinities to the Araucaria and Cunninghamia. Branches, leaves, and 

 cones of this genus are most abundant at Sultz les Bains, near Stras- 

 burgh. 



Mr. Witham reckons eight species of Coniferse among the fossil woods of 

 the Lias ; and five species, of which four are allied to the existing genus 

 Thuia, occur in the Oolite formation of Stonesfield. (See Ad. Brongniart's 

 Prod. p. 200.) For figures of Cones from the Lias and Greensand near Lyme 

 Regis, and the Inferior oolite of Northamptonshire, see Lindly and Hutton's 

 Fossil Flora, Plates 89, 135, 137. 



Dr. Fitton has described and figured two very beautiful and perfect cones, 

 one from Purbeck ? and one from the Hastings sand. Geol. Trans. 2d, Se* 

 ries. Vol. iv. PI. 22, Figs. 'J, 10, p. 181 and 230. 



