102 
EXPLANATION OE PLAN. 
b. Specimens of silicified and opalized woods, from various localities. 
c. Opalized or silicified trunk of an extinct Coniferous Tree ( Spondglos • 
trobus). Discovered embedded in basaltic lava, probably of 
Pliocene age, on the estate yf Richard Barker, Esq., Macquarie 
Plains, New Norfolk, Tasmania. Presented by the Tasmanian 
Commissioners for the 1851 Exhibition. 
d. Two portions of the silicified trunks of Coniferous trees (Cedroxylon, 
Kaup), from the Purbeck Bed, top of the Portland Oolite, Isle of 
Portland. 
d. d. A second trunk of Cedroxylon from same locality. 
e. Portions of the stems of Sigillaria and of a Lycopodiaceous Tree 
from the Coal Measures. 
