400 Traiisadions of the Societij. 



X. — On the Structure and Origin of Carboniferous Coal Seams. 

 By Edward Wethered, F.E.M.S., F.G.S., F.C.S. 



{Read ISth May, 1885.) 

 Plates VIII and IX. 



Up to the publication of the ' Proceedings of the Geological 

 Society of London ' for the years 1838-42, there was considerable 

 difference of opinion as to whether coal seams had accumulated 

 from drift vegetation or from vegetation which grew in situ. In 

 the ' Proceedings ' referred to, however, three papers appeared, 

 which served as powerful arguments in favour of the growth in 

 situ theory. The first of these was by Mr. John Hawkshaw* 



EXPLANATION OF PLATES. 

 Plate YIII. 



Figs. 1 anil 2. — Macrospores from the Sliallow seam of Cannock Chase, x 22. 



Fig. 3. — Microspores from tlie same, x 2G2. 



Fig. 4. — Scalariform tissue from the top of tlie lower beil of the Welsh " Four 

 Feet Seam," x 2G2. 



Fig. 5. — Spores from the centre of the same, x 262. 



Fig. G. — Horizontal section of the same from about the centre of the bed, 

 X IGO. 



Fig. 7. — Horizontal section of the same from the top of the bed close under 

 the clay parting, x IGO. 



Fig. 8. — Horizontal section of the Better Bed seam of Yorkshire, from the 

 uppermost 3 inches, x 12 J. 



Fig. 9. — B, Macrospore, x 22, and A, A, microspores, X 2G2, from the upper- 

 most 3 inches of the Better Bed. 



Fig. 10. — Horizontal section of the Better Bed at 4 inclies from the top, 

 X 12J. 



Fig. 11.— Macrospores from fig. 10, x 50. 



Fig. 12. — Portion of a macrospore from the same, showing caudate appendages, 

 X 50. 



Fig. 13. — Horizontal section of the Better Bed 10 inches from the top, x 12|, 

 shows the coal to be mainly made up of tissue and hydrocarlxjn. 



Fig. 14. — Portion of decomposed and carbonized cellular tissue from fig. 13, 

 X 50. 



Fig. 15. — Auother macrospore from fig. 10, showing caudate appendages, x 50. 



Fig. IG. — A microspore, x 262, from fig. 12. 



Plate. IX. 



Fig. 17. — A macrospore from the lowest bed of Splint coal of Wiiitehill 

 Colliery, near Edinburgh, x 22. 



Fig. 18. — Microspores from the same, X 262. 



Fig. 19. — Another variety of macrospore from the same, x 22. 



Fig. 20. — Another variety of microspore from the .same, x 262. 



Figs. 21 and 22. — Other macrospores and microspores from the same, x 262. 



Proc. Geol. Soc, iii. p. 139. 



