40 DESCRIPTION OF FOSSIL TREES DISCOVERED 



of vegetable remains. They are evidently composed of portions of plants, 

 of very different diameters and textures, compacted in a mass of decayed 

 vegetable substances, broken up by crystallizations of calcareous spar ; and 

 present each, if I may so say, a whole magazine of species. 



At present I intend to describe only one of these fossil bodies, of which 

 I have been able to determine the structure with sufficient minuteness. It 

 consists of a somewhat conical body, compressed, so as to have one diameter 

 about a half greater than the other. When removed from the inclosing 

 mass, it presented the appearance of natural joints, at the distance of about 

 two inches ; but I am not certain that these joints are not merely transverse 

 cracks, for there is no enlargement or depression at the places where they 

 occur. The extremity is rounded, and much compressed. At the lower 

 part the larger diameter was upwards of two inches, and at the extremity 

 one diameter is about half an inch, the other nearly a fourth. The surface 

 is slightly striated in the longitudinal direction, and the coating consists of 

 crystals of gypsum and calcareous spar. 



Fig. 7. Plate VIII. Represents a transverse slice of a confused mass of 

 organic remains, exhibiting the appearance offered by the fossil above ad- 

 verted to, in its transverse direction. The central part of this fossil was 

 composed of a distinct medullary cylinder, of which the tissue was for the 

 most part destroyed. This was surrounded by a circle of exceedingly regu- 

 lar tissue, radiating in series of hexagonal apertures, but apparently desti- 

 tute of medullary rays and vessels. The outer or marginal part is also 

 composed of the same tissue, with an inner margin waved by the crystalliza- 

 tion of siliceous matter ; and the intervening space presents numerous round- 

 ed portions of precisely the same appearance, in all of which the lines of 

 cellules preserve the same centro-marginal direction. The surrounding dark 

 portion represented in the figure, consists of numerous diversiform vege- 

 table bodies, compacted in a confused mass, interspersed with veins and 

 fissures filled with transparent infiltrated matter. 



Fig. 8. Represents a small portion highly magnified, of the tissue sur- 

 rounding the pith, as seen in the transverse section. It consists of very 



