1846.] 



BROWN ON ERECT FOSSIL TREES. 



395 



of Ferns, &c. Immediately under the roots of one of the trees, I 

 found Neuropteris cordata with basal leaflets, two species of Sphe- 

 nophyllum, two of Pecopteris^ Sphenopteris crenata, Asterophyllites, 

 and Pinnularia capillacea. 



All the upright stems apparently belong to the same species, and 

 are evidently young individuals, ranging from two to sixteen inches 

 in diameter only. In some other parts of the coal-field, fossil stems 

 three to four feet in diameter are not uncommon. 



It must be observed, that with the exception of the thin layer of 

 clay,^, there are no appearances of distinct surface-lines in the beds 

 /and h, although the eight trees have clearly grown upon at least 

 five different levels ; from which it may be inferred that the strata 

 were gradually subsiding during the period of their growth, the 

 amount of which subsidence, as well as its comparative rate, may 

 be estimated by the difference of level between the base of each 

 stem, and the diameter it attained, before the surface on which it 

 grew became submerged. 



The bed i is a soft slaty shale overlaid by the underclay k and I 

 of the main coal-seam; Stigmariae are numerous in this bed, but 

 they are by no means so plentiful as in the lower beds b and d. 

 The bed of shale /z, which forms the roof of the main coal, varies 

 in thickness, and is sometimes altogether wanting ; it abounds in 

 coal-plants of almost every description. 



Fig. 2. 



Ficr. 3. 



Fig. 2 is a sketch of one of the trees as it appeared when first 

 discovered in the face of the cliff, with roots of Stigmariae united 

 to it. 



Fig. 3 is a horizontal section, showing the direction of the roots, 

 with their ramifications, so far as they could be conveniently fol- 

 lowed. This section was obtained by cutting into the cliff until the 

 rock became so hard that no further progress could be made without 

 great labour. 



The stem, although standing exactly at right angles to tlie dip, is 

 slightly flattened, the diameter in one direction being eight and in 

 the other only six inches, as shown in fig. 3. The bark, converted 



