1863.] DAWSON DEVONIAN PLANTS. 465 



18. Carpolithes ? siliojta, spec. nov. PI. XVII. fig. 4. 



Elongate, smooth, flattened, sides slightly sinuate ; two inches or less 

 in length; a quarter of an inch or less in breadth. 



These objects are too thick and carbonaceous to have been fronds 

 or leaves, and too regular in form to be fragments of stems. They 

 may, however, have been swollen extremities of roots. 



§ III. Gaspe, Canada. 



The Plants collected at Gaspe by Mr. Bell, last summer, consist 

 principally of Psilophyton princeps in all states of preservation, 

 still further illustrating the predominance of that species in the 

 Gaspe sandstones, many parts of which were then, for the first time, 

 explored by Mr. Bell. In addition to the facts previously known re- 

 specting this Plant, the specimens now obtained illustrate the internal 

 structure of its creeping rhizomes, previously found only flattened or 

 as casts. Mr. Bell has also added to the Gaspe flora Leptophloeum 

 rhombicum, previously found only at Perry, and Didymophyllum re- 

 niforme, a Plant of the Middle Devonian of New York, thus con- 

 necting by new links the contemporary floras of these distant loca- 

 lities. His collection also contains two new and curious species of 

 fossil wood, and several fragments possibly indicating new species, 

 but at present of ambiguous character. The more important of these 

 discoveries I indicate under the following heads. 



/ 1. Psilophyton princeps, Dawson (rhizomata). PI. XVIII. fig. 22. 



Sir W. S. Logan had obtained from the marine limestones at the 

 base of the Gaspe sandstones, constituting the lowest members of 

 the Devonian Series, if they are not Upper Silurian, a few flattened 

 stems, which in my paper on the Devonian Plants of Gaspe* I 

 referred with doubt to Psilophyton. Mr. Bell has collected many 

 additional specimens, some of them perfectly flattened, and which, 

 but for obscure remains of the surface-markings, might readily be 

 mistaken for Algae ; others retain more or less perfectly their cylin- 

 drical form. The latter are all rhizomata, usually about half an 

 inch in diameter, and retain the structures of the outer bark and 

 internal axis in a calcified state, the cell- walls being changed into 

 coaly matter. The outer bark is seen under the microscope to con- 

 sist of cellular tissue, dense toward the surface, and more lax within, 

 as seen in a transverse section ; while in the longitudinal section the 

 outer portion is found to consist of cells elongated in the manner of 

 bast-tissue, and the inner of ordinary parenchymatous cells. The 

 thick inner bark, which was probably of lax cellular tissue, has disap- 

 peared. The slender cylindrical axis consists of woody fibres exter- 

 nally, and of scalariform vessels within ; it has a vacant space of 

 very small size in the centre, which may represent a pith, but is 

 perhaps merely a result of decay and shrinking, which have caused 

 the vascular bundle to separate from the woody sheath, and the 

 fibres of the latter to separate in such a manner as to present very 



* Quart, Journ. Gteol. Soc. vol. xr. 



