432 Geological Specimens from Tasmania. 
No. 81, From St. Paul’s Plains. 
This specimen is limestone conyerted into chert and chal- 
cedony ; and would, if cut and polished, make a nice gem. 
The shells are of the family of 7’rigonotreta. 
No. 82, From a bed of Rock at the foot of Cummins’ 
Hill, New Norfolk. 
This is magnesian limestone rock. 
No. 38, From Hunterston, near Bothwell. 
These specimens are magnesian limestone, and all marked 
with impressions of the skin of some reptile or crustacean. 
We have the same markings upon the magnesian lime- 
stone near Sunderland in this country, and no doubt the 
same formation. 
No. 84, Scorie from the vicinity of the extinct volcanic 
crater at Macquarie Plains. 
This is a beautiful specimen of scorie, and when viewed 
through a magnifying-glass has a gem-like appearance. 
No. 85, Minute fibres resembling asbestus, collected from 
the outer coating of the fossil pine tree at Macquarie Plains. 
Had this been presented to me without its history, I 
should have concluded it was asbestus. Mineralogists have 
what they call ligniform asbestus yery much resembling this 
specimen, and they say it breaks into long masses in the 
direction of the fibres, and also separates with ease. This 
description answers to the outer coating of the fossil pine 
tree which you haye sent me. 
Query.—Has heat anything to do as an agent in changing 
wood into asbestus ? 
All the localities where it is found would lead to this con- 
jecture, for it is generally found in primitive rocks in all 
countries. ‘This specimen is nearly become all silex, and 
when seen through a magnifying-glass it exhibits long, 
slender, transparent crystals. 
