On Carhoniferous Coal Seams. By Edivard Wethered. 415 



macrospores are seen, measuring about * 003 of an inch in diameter, 

 and associated with microspores of about "0005 in diameter. In 

 fig. 22 another of these macrospores is shown, having a triradiate 

 marking. It was while drawing the last figure that I noticed minute 

 spine- like projections on the surface, and on further examination they 

 appeared to pass into the inner surface ; this is shown in the figure. 

 Mr. E. T. Newton * noticed the same feature in the spores which 

 occur in Tasmanite and Australian white coal, and I also pointed 

 out the same thing in my paper t " On the Occurrence of Spores 

 of Plants in the Lower Limestone Shales of the Forest of Dean." 

 Mr. Newton regards them as minute lines (tubes ?) passing from 

 the outer to the inner surface. I am, however, inclined to regard 

 them as spines. I have said that it was while drawing fig. 22 

 that I first noticed these spines (?), and thinking that possibly I 

 had overlooked the feature in the spores previously examined, I 

 again placed them under the Microscope. I had before noticed a 

 granular appearance on the surface of the Macrospores, and dark 

 spots on the microspores ; these I now resolved into the same spine- 

 like projections as seen in fig. 22. In fig. 23, I have magnified 

 262 diameters a portion of the surface of fig. 17, and the spine (?) 

 like projections are clearly shown. 



The lowest bed of the " Splint Coal " is replaced abruptly, and 

 without clay parting, by the " Eough Coal " or middle bed of the 

 seam. The transition in the structure of the coal is most striking, 

 and is illustrated in fig. 29, which is magnified 12^ diameters, the 

 same as fig. 24, with which it should be compared. This bed is 

 mainly made up of numerous layers varying in degrees of lustre, 

 and averaging about half an inch thick. A microscopic section of 

 the brightest of these shows only a few spores but plenty of 

 hydrocarbon. In the duller layers, spores were fairly numerous, 

 but for the most part were a distinct variety to those which appear 

 in the bed below ; this is shown by figs. 25, 26, 28, which are 

 magnified 50 diameters. The " Eough Coal " is followed, without 

 parting, by the " Upper Splint " bed. The lustre is mostly dull 

 and the greater portion of the coal is simply a mass of macrospores 

 and microspores, some of which are a different species to those 

 which predominate in either of the beds below. The relative size 

 is sufiicient to determine that point, and the fact may be seen at a 

 glance by comparing the horizontal section of this bed (tig. 30) 

 with that of the two lower ones, figs. 24 and 29. They are all 

 magnified 12^ diameters, so as to facilitate comparison. 



I now come to another important part of my subject, and it is 

 one which is necessarily somewhat speculative ; it is the relation and 

 character of the coal-forming vegetation. Among those who have 



* Geol. Mag., ii. (1875) p. 339. 

 t Proc. Cotteswold Club, 1884. 



