m ^ 



'-'i i^' 



Fig. 1. 

 2. 

 3. 



4. 

 6 



6. 



7. 



9. 

 10. 



11. 

 12. 

 13. 

 14. 

 15. 



16. 

 17. 



Fig. 18. 

 19. 



20. 



21. 



22. 



23. 



24. 

 25. 



PRE-CARBONIFEROUS PLANTS. 



EXPLANATION OF THE PLATES. 



Plate i. Dadoxylon and Ormoiylon. 



Dadoxylon Ouangondiunum, — Tran.fversc section of a calcified specimen, showing 

 rings of grow'tli and radiating structure, natural si/.o. 



Longitudinal section, radial, showing discigcrous wood-cells, and 



medullary rays, 100 diams. 



Longitudinal section, tangeutial, showing wood-cells and medullary 



rays. 



Portion of wood-cell, showing hexagonal areolation and pores, 3 



diameters. 



Dadoxylon 77ai//,— Longitudinal section, showing wood-cells, (discigerous), and 

 medullary ray. 



Portion of wood-cell showing areolation and pores, 300 diameters. 



Dadoxylon Newhcrryi, — Longitudinal section, radial, showing discigerous wood- 

 cells and medullary ray. 



Longitudinal section, tangential, showing wood-cells and medullary 



rays, 100 dinmetera. 



Portion of wood-cell showing areolation and pores, 100 diametcfS. 



Ormoxylon Erianum, — Carbonized stem with casts of pith cavities (a, a) natura 

 size. 



Wood-cell showing areolation and medullary ray, 100 diameters. 



Portion of wood-cell, showing areolation and pores, iiOO diameters. 



Portion of wall of cell showing one areole and pore, 000 diameters. 



Restored stem — (a) pith cavities, (b) cellular piih, (c) wood. 



Longitudinal section of Sternbergia pith of Dadoxylon Ouungondianum 



showing a tendency to division into lenticular spaces, similar to those 

 of Ormoxylon. The dark lines represent the phragmata coal 

 escing toMirds the centre. Twice natural size. 15a one of the phrag- 

 mata of ( lis Sternbergia showing the vacant space in the centre. 



Longitudinal section of pith of the modern Cecropia peltata, showing 



partitions and spaces (a, a). Natural size. 



Longitudinal section of Sternbergia pith of Dadoxylon materiarium from the coal 

 formation, showing the arrangement of the phragmata, natural size. 



Plate ii. Prototiuites. 



Prototaxites Logani, — Fragment 19 inches in length from a large trunk ; inner side 



showing rings of growth ; surfaces at a, n, edges at b. 

 Fragment from a trunk 3 ft. in diameter, and showing the outer surface, 



with transverse ribs and marks of insertion of branches at a, a. 



Actual width of the fragment 2 feet. 

 Transverse section showing the wood-cells, and a medullary ray at 



(a, a). 100 diameters. 

 Transverse section, showing wood-cells, medullary ray (a, a) and ring 



of growth (b). 100 diameters. 

 Longitudinal section, showing the extremity of a medullary ray — 



tangential section, 100 diameters. 

 Transverse section, the wood-ceils seen imperfectly at a, a, but for the 



most part obscured by concretionary structure. 

 Longitudinal section, showing wood cells, 100 diameters. 

 Transvenie section, sliowing medullary rays at a, a, and Ime of growth 



at b, b, 20 diameters. 



