217 



those embarrassing facts toucliing the mutability of sj^ecies 

 which have been gained by a wider experience. 



A revision of the nomenclature of the freshwater shells of 

 Australia is urgent, and I venture to offer my helj) in insti- 

 tuting a critical comparison of the Tasmanian species, inter se 

 and with continental forms. For this purpose it is absolutely 

 necessary that the collections submitted for examination be 

 larsje and varied. 



NOTES ON BORING OPERATIONS IN SEARCH OF 

 COAL IN TASMANIA. 



By T. Stephens, F.O.S., Etc. 

 IReacl June 9, 1884.] 

 The attempt which is being made, by means of the diamond 

 drill, to test the question of the existence of deep lying 

 seams of coal at Tarleton, on the Mersey, and near the 

 Cascades Brewery, at Hobart, calls for some notice. The 

 work is not yet so far advanced as to demand more than a 

 brief statement of the circumstances under which it has 

 been undertaken. It is probably pretty generally knovm 

 now that the seam of coal which has been worked for many 

 years past, in the Mersey district invariably underlies 

 certain marine calcareous beds, the presence of which was 

 formerly supposed to indicate that the base of the coal 

 measures had been reached. This feature is absent from the 

 coal measures of the Eastern and Southern districts, and all 

 such evidence as is forthcoming leads one to suppose tliat 

 the latter belong to a later epoch than those of the Mersey 

 and other districts bordering on the North Coast. 



To go fully into this question would require more time 

 than I can command, and no definite conclusion can be 

 arrived at until a reasonably complete series of specimens of 

 the plant remains of the several formations is available for 

 comparison and examination. For the basis of a provisional 

 classification I will take the succession of rocks composing or 

 associated with the coal measures of New South Wales, with 

 which Tasmania has more in common than with any of the 

 other Australian Colonies. The following is a rough outline 

 of the order in which they occur : — 

 T •r.c ;^/o\ i Wianamatta shales. 



T^^^'^^"(-> I Hawkesbury rocks. 



Permian (?) Upper coal measures (Newcastle coal). 



f Upper marine beds. 



I Lower coal measures (Anvil Creek, Greta, 



Cai boniterous ^ -^ower marine beds. 



I Lower carboniferous. Port Stephens, etc. Plant 

 l^ and marine beds (without coal). 



