[SIR J. w. DAWSON] ON THE GENUS LEPIDOPHLOIOS 61 



in similar stems been regarded as an equivalent of corky bark. This 

 tissue is infiltrated with pyrite, so that it can be seen only as an opaque 

 object, and is very imperfectly preserved. The outer bark and remains 

 of the leaf-bases are in the state of dense shining coal. (Plate VI. and 

 figures in the text.) 



The axis in cross-section shows a central space without structure, 

 and with only obscure indications of transverse partitions of the Stern- 



(i; 



Fig. B.— Original Sections of Lepidophloios Acadianus, 1865. 



(1) Cross-section of Lepidophloios, showing (a) pith, (b) woody axis, (e) inner bark 



and leaf-bundles, (d) corky bark, (e) epidermis. 



(2) Part of cross-section more magnified, showing double ring of scalariform 



fibres and leaf-bundles. 



(3) Scalariform fibres still more enlarged. 



bergian type. Sun'ounding this is a double cylinder of scalariform 

 vessels or fibres,^ coarser within and finer without, but not showing any 

 radiating arrangement or medullary rays. The outer margin of the 

 cylinder presents a series of loops or notches, each showing the section of 

 one of the bundles of vessels proceeding to the leaves, each of which 

 seems to have been enclosed in a sheath, which has perished. They appear 

 to have run vertically, parallel to the surface of the stem for a space be- 

 fore diverging toward the surface. The cone-scars being placed at inter- 

 vals of about 2^ inches vertically, are represented only occasionally on 

 the slices by larger bundles. This structure may be considered as iden- 

 tical with that of Malonia as described by Williamson as Halonia regularis 



^ I do not use the term " tracheids," believing it to be altogether inappropriate 

 to this kind of tissue, though used by many German authorities. 



