364 DR D. H. SCOTT ON THE 



PLATES III.-VI. 

 Original drawings, made, under the author's supervision, by Mr G. T. Gwilliam. 



Plate III. 

 Calamopitys fascicularis. 



Fig. 1. Transverse section, showing the contracted pith, primary xylem-strands, and inner part of the 

 secondary wood. From a section adjacent to that from which diagram 1, p. 334, was drawn, and showing 

 practically identical structure. The strands are lettered as in the diagram. A, large xylem-strand in contact 

 with secondary wood, x 2 ; px. protoxylem ; B, still larger strand, beginning to pass out into the wood ; px, 

 protoxylem ; C, direction of outgoing leaf-trace shown in diagram 1 ; a, b, c, reparatory strands of the outgoing 

 bundles A, B, and C ; d, strands of the orthostichy D, cut low down in their course ; e, similar strands of the 

 orthostichy E. (See p. 333.) x 24. (K 540 A .) 



Fig. 2. Transverse section, showing one of the smaller xylem-strands, v.b. (this is the larger of the two 

 marked e in diagram 2, p. 335) ; px, protoxylem. x 2 , secondary wood, showing pits on the horizontal walls of 

 the dilated tracheides (cf. fig. 3). (See p. 338.) x 140. (K. 628.) 



Fig. 3. Radial section, from the border of the pith and wood, p, pith ; v.b., primary xylem-strand ; 

 px, its protoxylem ; p', circum-medullary tissue ; x 2 , inner elements of secondary wood, showing the short, 

 irregular tracheides (cf. fig. 2). (See pp. 338 and 339.) x about 100. From a new section of Mr Kidston's 

 specimen. 



Fig. 4. Radial section of the secondary wood, showing the tracheides, with multiseriate bordered pits, 

 and the medullary rays. (See p. 338.) about x 120. (K. 540 1 .) 



Fig. 5. Tracheides in radial section, more enlarged, to show the hexagonal pits, with slit-like pores. 

 (See p. 338.) x about 300. (K. 540 1 ). 



Plate IV. 

 Figs. 6 and 7. Calamopitys fascicularis. 



Fig. 6. Tangential section through the secondary wood, showing tracheides and medullary rays, m.r. 

 b.p., bordered pits of the tracheides in section. (See p. 339.) x about 120. From the Williamson specimen 

 (W. 1392.) 



Fig. 7. Tangential section through the wood, showing an outgoing leaf-trace, px., protoxylem of the 

 leaf-trace ; 'pa., parenchyma, accompanying the leaf-trace ; m.r., medullary rays. (See p. 337.) x about 30. 

 (W. 1392.) 



Figs. 8-12. Calamopitys beinertiana. 



Fig. 8. Transverse section, showing a large primary xylem-strand, v.b., just entering the secondary wood, 

 x 2 , from the pith, px, protoxylem of the primary strand. (See p. 342.) x 60. (K. 677.) 



Fig. 9. Transverse section, showing a smaller xylem-strand, v.b., at the inner margin of the wood, x 2 . 

 px, protoxylem of the strand, which is here of the " hippocrepif orm-endarch " type. (See p. 343.) x 60. 

 (K. 677.) 



Fig. 10. Somewhat oblique radial section of a primary xylem-strand. px, spiral protoxylem-element of 

 the strand. The ill-preserved element to the right is a tracheide. (See p. 343.) x 100. (K. 677 H .) 



Fig. 11. Part of a large primary tracheide, showing the numerous rows of hexagonal bordered pits. 

 (See p. 343.) x about 200. (K. 677 G .) 



Fig. 12. Tangential sections from the secondary wood — 



A, showing part of a long medullary ray. x 70. (K. 677 K .) 



B, showing a 2-3-seriate ray with irregular adjacent tracheides. x 90. (K. 677 K .) 



C, showing several short rays, x 90. (K. 677 M .) (See p. 343.) 



Pla.te V. 

 Fig. 13. Calamopitys beinertiana. 



Approximately tangential section of the secondary wood, passing obliquely through a large outgoing leaf- 

 trace, accompanied by parenchyma. (See p. 344.) x about 50. (K. 677 L .) 



