476 



CONIFERS OF THE COAL PERIOD. 



Tig. 529. 



[Ch. XXIV. 



Fig. 530. 



Surface of another individual 

 of same species, showing form 

 of tubercles. (Foss. Flo., 34.) 



SUgmarxa jicoides, Brong. $ nat. size. (Foss. Flo., 32). 



woody system much resembling that of Sigillaria, the structure of the 

 vessels being, like it, scalariform. 



Coniferce. — The coniferous trees of this period are referred to five 

 genera ; the woody structure of some of them showing that they were 

 allied to the Araucarian division of pines, more than to any of our 

 common European firs. Some of their trunks exceeded 44 feet in 

 height. Many, if not all of them, seem to have differed from living 

 Coniferce in having large piths ; for Professor Williamson has demon- 

 strated the fossil of the coal-measures called Sternbergia to be the pith 

 of these trees, or rather the cast of cavities formed by the shrinking 



Fig. 531. Fragment of coniferous wood, Dadoxylon, 

 Endlicher, fractured longitudinally ; from Coalbrook 

 Dale. W. C. Williamson.* 

 a. Bark, 

 &. Woody zone or fibre (pleurenchyma). 



c. Medulla or pith. 



d. Cast of hollow pith, or " Sternbergia. 1 ' 



Magnified portion of fig. 531 ; transverse section. 

 g. Pith. 6, &. Woody fibre. e, e. Medullary rays. 



Manchester Philos. Mem., vol. ix, 1851. 



