168 Mr Nicol on Fossil Woods. 



Fig. 1. Plate III. is a transverse section of a small portion of a petri- 

 fied conifera, in which the natural structure is nearly as perfect as 

 in any living tree of the pine or fir tiibe« At a there is a rent 

 filled with calcedony in the specimen, shewing a dislocation in some 

 of the rows of pores, b is the outer, and c the inner edge of the 

 annual layer d. 



Fig. 2. is a transverse section of another specimen of petrified conifera, 

 in which the reticulated structure, though variously twisted from 

 its natural position, is perceptible throughout the greatest part of 

 the whole. At e the reticulated structure is quite obliterated, the 

 medullary rays alone being preserved. 



Fig. 3. is a section of a very small portion of a petrified conifera, in 

 which the reticulated structure is observable only in a very few 

 places. The greatest part of the whole specimen has the appear- 

 ance of the layer at^ and the few places retaining the reticulated 

 structure have the appearance as represented at g. 



On the ConifertE at present growing in Australia. 



As nearly all the fossils and woods hitherto brought from 

 Australia belong to the coniferous order, the following observa- 

 tions on the present coniferae of Terra Australis, communicated 

 by Mr D. Don. cannot fail to prove interesting to naturalists. 



The species of this order are not numerous in Terra Austra- 

 lis ; those already discovered amounting to about ten, the same 

 number as has been hitherto observed in New Zealand. Of the 

 Australian portion of the order Phylhcladus rhomboidalis, 

 Dacrydium cupressoides (Huon pine), and a species of Podo- 

 carpus belong to Van Diemen's Land, and the remainder, con- 

 sisting of Araucaria Cunninghamii^ two species of Podocarpus, 

 and four or five species of CalUtris, are found chiefly in the 

 principal parallel of New Holland, and mostly on its eastern 

 side ; for it is a curious fact, that they gradually become more 

 rare as we advance westward. The genera are nearly the same 

 as in New Zealand ; but while the fir tribe (Abietinea) is re- 

 presented in New Holland by Araucaria Cunninghamii, the 

 former country possesses also a single representative of that 

 group in the Dammara Australis ; and of the remaining genera, 

 Dacrydium^ Podocarpus, and Phylhcladus belong to the Yew 

 tribe (Taxinea), and Callitris to the Cypress tribe {Cupressi- 



