FOSSIL PLANTS OF THE OAKBONIFEROUS SYSTEM. 



741 



and bitumen gradually forced outwards, and collected on the exterior 

 surface. 



" The charcoal which remains in the stems renders their minute 

 internal structure singularly distinct when a thin transparent slice is 

 placed imder the microscope. Longitudinal woody bundles, transverse 

 medullary rays, crowded cells of the longitudinal fibres cut crosswise, 

 are all seen most characteristically ; and in one specimen two inches 

 in breadth the boundaries and whole structure of five annual layers 

 •of wood are displayed characteristically, even to the naked eye. On 

 the polished surface of one of the great stems, too, the eye can easily 

 trace many annual rings for long distances." 



Stembergia is considered by Williamson as a Dadoxylon, with a 

 discoid pith, like that seen now-a-days in the Walnut, Jasmine, and 

 Cecropia peltata, as well as in some species of Euphorbia and in some 

 Conifers. Sternbergia approximata is named by him Dadoxylon 

 approximatum. Hooker has shown from the structure of Trigono- 

 carpus, a not uncommon fruit, that it is a coniferous fruit, nearly 

 allied to Salisburya. Noggerathia, and a few other plants, such as 

 Flabellaria and Aitisia, are referred by Brongniart to Oycadacese. 

 Flabellaria borassifolia, according to Peach, has leaves like Yucca. 

 Noggerathia has pinnate leaves, cuneiform leaflets, sometimes fan- 

 shaped ; the veins arise from the base of the leaflets, are equal in size, 



Fig. 920. 



Fig. 921. 



Pig. 920. Cardiocarpum Lindleyi/colleoted by C. W. Peach, near Falkirk, a peculiar fossil 

 ■of the Coal-measures, supposed to be the fruit of Antholithes. Fig. 921. Pothocites 



■Grantoni. a. Spike natural size. 6, Portion of the spike magnified, c, Perianth 4-cleft. 

 magnified. 



