36 OBSERVATIONS ON FOSSIL VEGETABLES, 
they are variously distorted. This figure represents one of the most regu- 
lar portions. 
Fig. 4. Represents a distorted portion of the same. There are hardly 
any traces of medullary rays in this fossil, which is in general remarkable 
for the regularity and little breadth of its concentric layers. 
Fig. 5. Portion of a section of fossil wood from the lias, near Whitby. 
In this wood, the concentric layers are very large and regular. It is espe- 
cially remarkable for the regularity of the medullary rays, which present 
few intersections, but appear like continuous tubes. 
Fig. 6. Transverse slice of a small portion of the most regular part of a 
very large mass found by Mr Nico1, in 1815, 2m situ, in the upper lias, 
about four miles north from Whitby, near Sandsend. It is very much dis- 
turbed by the intervention of calcareous spar, as is represented in the figure. 
The structure is concentric. The figure is of the natural size. 
Fig. 7. Portion of the same magnified, shewing part of two concentric 
layers and their junction. In the unaltered parts, the structure is very re- 
gular, but exhibits few traces of medullary rays, and these not continuous. 
The meshes are about the size of those of our recent pines. 
Fig. 8. Another portion of the same, magnified in the same degree, ex- 
hibiting the confused appearance resulting from the intervention of calea- 
reous spar. 
Fig. 9. Portion of a transverse slice of a fossil tree from the Whitby 
lias, shewing part of two layers. In this tree, the medullary rays are very 
distinct, as well as the concentric layers. 
Fig. 10. Portion of a transverse slice of another tree from the Whitby 
lias, exhibiting the same general arrangement, but with much larger cellules. 
Fig. 11. Portion of a transverse slice of a fossil tree from the grey lime- 
stone, near Whitby. The structure of this fossil is extremely distorted and 
altered by the intervention of calcareous spar, the cellular texture being 
thrust together in black masses. The portion represented is the most re- 
gular, many of the other parts being perfectly opaque. 
Fig. 12. Portion of a transverse slice of another fossil tree from the 
Whitby lias. This, also, is very much distorted and broken up; but as little 
