28 OBSERVATIONS ON FOSSIL VEGETABLES, 
in the centre, others having them distributed in various parts. The exte- 
rior is irregularly grooved in the longitudinal direction. No indication of 
branches was observed. ‘The nature of the interior will be best understood 
by referring to the figure. 
Within an external layer of coaly matter f, f/f, is exhibited an irregu- 
larly oval surface, presenting various modifications of colour and texture. 
b, Is the centre, converted into calcareous spar, of which substance all 
the white rays and veins consist. 
a, a,a, Portions retaining organic texture, and arranged in a radiating 
manner, from the centre b, towards the circumference, but losing themselves 
in the apparently cellular mass of which the greater portion of the stem is 
composed. 
c,¢,¢, Portions of the same nature as a, a, a, dispersed irregularly, and 
presenting in the transverse section an oval or oblong figure, but running 
continuously through the mass, in its longitudinal direction. 
d, d, d, The mass in which the organic portions are imbedded. It con- 
sists of crystallizations of calcareous spar, surrounded by carbonaceous and 
clayey matter, and presents somewhat of a cellular appearance, but is not 
organic. 
e, €, Indurated argillaceous matter. 
This much is shewn of the external forms and internal arrangement of 
these remarkable stems, as seen by the naked eye. What the microscope 
discloses, will be seen in the next Plate. 
The following is the analysis of a portion of one of these fossils, weigh- 
ing 20 grains: 
Carbonate of Lime,’ : , - -' 5s - = 6:65 
arb ilsta ken ee ibe iin ee dae ee OsOU. 
Tron\(Peroxide) ii. mee uneil- -eO-6S 
Loss, nt LCE! 2 ses Oo 
20.00 grains. 
