CORDAITEAE 523 



The habit of the Cordaiteae must have been 

 different from that of any trees with which we are now 

 familiar. The species with comparatively short leaves 

 may be compared with such Coniferae as Agathis {e.g. 

 the Kauri Pine of New Zealand), or with certain forms 

 of Podocarpus, and these trees may best serve to give 

 us some idea of the appearance of the extinct family. 

 But the longer-leaved species must have had a habit 

 very different from anything which we are accustomed 

 to associate with Gymnosperms at the present day. 



Branches, showing the characteristic marks of 

 Cordaites, have been found by Grand'Eury with 

 structure preserved, and this important discovery en- 

 abled palaeobotanists to identify a large proportion of 

 the apparently Coniferous woods of the Palaeozoic 

 strata, named Araucarioxylon or Dadoxylon, as belonging 

 to the Cordaiteae. The anatomical structure will be 

 described below ; here it is only necessary to say that 

 the large size of the pith, sometimes attaining a 

 diameter of nearly 4 inches, is characteristic of these 

 plants, and at once distinguishes their stems from those 

 of the Coniferae. 



Casts of the pith-cavity of Cordaites are well-known 

 and characteristic fossils, which used to be called Artisia 

 or Sternbergia. They are cylindrical, or somewhat 

 ribbed casts, sometimes very slender, but usually an 

 inch or more, and sometimes approaching 4 inches, in 

 diameter, and marked by numerous transverse constric- 

 tions at very short intervals, so that the whole resembles 

 a pile of coins. Williamson, in 1851/ found a cast of 



1 "On the Structure and Affinities of the Plants hitherto known as 

 Sternbergiae" Mem. Manchester Lit. and Phil. Soc. ser. ii. vol. ix. 

 1851. 



