Cordaites are locally very abundant, they are not so gener- 

 ally diffused geographically as the Sigillaria and Le- 

 pidodendra. The oldest species known to me is G. Robbii 

 from the Middle Erian of New Brunswick, where it occurs 

 with two species of Antholites A. devonicus and A. floridus, 

 perhaps its male and female flowers, and with the species 

 of Cardiocarpa already mentioned. I observe it has been 

 stated that C. Robbii has been found in the Upper Silurian 

 of Hainault. 1 The latest species known in Acadia is 

 C. Simplex found in the Permian of Prince Edward Island 

 and also in the newer Coal formation of Nova Scotia. 

 Antholites and Trigonocarpa are found in the same beds, but 

 no Cardiocarpa. 



Stems of Cordaites showing structure have not yet been 

 certainly recognised in this country. This leads, however, 

 to the question whether such stems may not have been 

 referred to other plants. I may mention more particularly 

 those named Dadoxylon, (Araucarioxylon) and Sigil- 

 laria. 



With a view of settling this question, I obtained through 

 the kindness of the eminent French palaBobotanist, M. 

 Renault, specimens of the stems from St. Etienne referred 

 by him to Cordaites. These I found to be of two types which 

 may be distinguished as follows : 



(a) Silicified stem, associated with leaves of Cordaites 

 proper (C. borassifolia or allied). This has a large cellular 

 pith, which has, however, mostly disappeared, leaving a 

 hollow cylinder occupied with structureless silica and vege- 

 table debris. The pith has been nearly an inch in diameter 

 and showed no distinct evidence of Sternbergia structure. 

 The woody cylinder surrounding the pith was less than a 

 quarter of an inch in thickness, and consisted of two layers. 

 The inner of no great thickness, shows pseudo-scalariform 

 tissue, while the outer layer, which is radially arranged, is 

 composed of porous woody tissue, the pores or discs being 

 sometimes in one row, and sometimes as many as three 



1 Ward, History of Palseo-botany. 



9 



