?ard the* 

 Kin the 



3d the be- 



Ironi those 



|i thu.se 90- 



Cnlamila 



described i 



otherwise ' 



lio roots of 



DAWSON — SIOILLARIA, CALAMITE9, AND CALAMODENDRON. 161 



Wig. 9. Stcmhergia, pith of the same, natural size; 9rt, discigerous tissue of the 

 same. 



10. Another stem, probably Conifprous, w'.h Stembergia pith. 



1 1 . Woody tissue of j)ro8trate SigiHarin : 1 1 «, bast-tissue of the same. 



12. Woody i-issuo of a Sigillaria; 12 <^ medullary ray. 

 l.'{. Tissue of a Sfernhergia similar to fig. I). 

 14, 15, 10, Discigerous tissue of erect trees {Siyillar'ue) in mineral charcoal. 



Plate IX. 



, Fig. 17. Calamndendron approximafmn, cast of pith; 11 a, lib, discigerous and 

 Hcnlariform tissue of the same. 



18. Calavwdcndron invested with woody tissue : A, pith ; B, woody cylinder ; 



18«, cross section; 18/>>, cross section, magnified, showing compression 

 of the tissue ; 18 c, discigerous and pseudo-scalariform tissue of the 

 same. 



19. Portion of a multiporous vessel of a true Calamites, magnified to the 



same scale with figs. 17« & 176. 



20. Stem of erect Cidamodendnm (S. Joggins, Nova Scotia), showing its 



external surface, one-third nat. size. 



21. Base of stem of Calamites (S. Joggins), showing rhizoma, reduced. 



22. Node of Calamites, showing scars of verticillate branchlets and of radial 



processes, 



Plate X. 



]l%. 23. Eadial section of stem of Sigillaria of the type of S. Brownii, Diiwson, 

 restored, natural size: «, pith; h, woody cylinder ; c, cellular inner 

 bark ; d, fibrous bark ; e, outer cortical layer. 



24. Radial section of the woody cylinder, magnified (letters as above) ; and 



portions of the tissues more highly magnified below : h], inner pseudo- 

 scalariform cylinder; b'l, 3, 4, discigerous outer cylinder. 



25. Radial section, more highly magnified, showing one of the radiating 



bundles of vessels (this section has been inverted) ; 2a «, single pseudo- 

 scalaril'orni vessel from radiating bundle. 

 ■ 20. Tangential section of the same stem, showing the woody fibres and one 



of the radial bundles, and the medullary rays. 

 > 27, Tangential section showing woody fibres and medullary rays, more 

 ' highly magnified. 



28. Radial arrangement of wof)dy fibres, magnified. • 



\ir^ 2',). Fibres or elongated cells of the bark {d). 



Note. — All the drawings oi scparafe fibres and vessels m the above figures are 

 on one scale. 



