10 



The specimens were associated with branches of Walchia, 

 leaves of Cordaites Simplex, Trigonocarpa, and also with 

 [trunks of Dadoxylon (D. materiarium.) 



Since the publication of the paper 

 referred to, Mr. Bain has made addi- 

 tional collections, more especially on 

 St. Peter's Island and other places on 

 the south side of Prince Edward Island, 

 some of which have been sent to the 

 Geological Survey at Ottawa, and 

 others to the writer, along with draw- 

 ings of specimens still in Mr. Bain's 

 possession. These specimens show the 

 internal structure of the pith and woody 

 cylinder, and varieties in the external 

 markings which may perhaps indicate 

 distinct species; and along with the 

 stems, M r. Bain has found leafy branch- 

 lets and fruits of a peculiar form which, 

 from their association, he regards as be- 

 longing to these plants. 



The principal external differences in 

 Mr. Bain's specimens, consist in greater 

 or less size and distance apart of the long, 

 projecting, spindle-shaped and furrowed 

 ridges which mark the stems, and in the 

 presence or absence of enlarged nodes 

 marked with whorls of tubercles. This 

 last difference may be specific, and ap- 

 FIG. 3. Portion of stem pears to correspond with certain differ- 

 drSly MnS ences in the structure of the wood. 



Several of the specimens showing structure, represent the 

 pith-cylinder alone in a silicified state, and these specimens 

 have the external markings as perfectly shown as in the 

 sandstone casts, so that the supposed external markings of 

 Tylodendron may in some cases belong to the outer surface 

 of the pith-cylinders. The internal structure of these medul- 

 lary cylinders shows, in some cases, the transverse dia- 



