BY R. H. CAMBAGE. 557 



Syncavpia laurifolin (Turpentine), so widely known in con- 

 nection with its value as piles in salt water, occurs just beyond 

 The Oaks, or near the margin of the shale. The disti'ict 

 bounded by lines roughly joining Picton, The Oaks* Penrith, 

 and the north-eastern side of Parramatta is largely composed 

 of deep beds of what is known as Wainaniatta 8hale, which over- 

 lies the Hawkesbury Sandstone, but becomes shallow, where 

 more denuded on the higher levels outside the margin of this 

 area. Now, it is remarkable that the Turpentine follows 

 practically all round this margin, and also on the isolated 

 outside remnants, as at Springwood, etc., though it rarely 

 encroaches upon the deep shale-area, but ceases when the 

 thickness exceeds about 100 feet. Its presence within this 

 area would indicate the vicinity of sandstone, or at least 

 sandy soil. Its occurrence near The Oaks, therefore, is in 

 keeping with its usual discrimination in regard to selection 

 of geological formations. This species extends northwards 

 into Queensland, and goes south of Sydney to within about 

 a dozen miles of Bateman's Bay. It is of interest to note in 

 connection with its selection of soils, that its terminal point 

 in the south is practically identical with that of the great 

 Permo-Carbonif erous coal-basin . * 



da.tuaritia rjlaiira (Swamp-Oak) was noted a few miles 

 from Camden, and was only sparsely represented. This is 

 the common saltwater-oak found all along our coast ; but it 

 follows up certain freshwater creeks, which are sluggish and 

 contain brackish water. The presence of this species on the 

 uplands suggests saline conditions. (See these Proceedings, 

 1901, p. 687). 



C suherosa (Black Oak) was confined to the sandstone- 

 area, a formation to which it is partial, being a lover of 

 siliceous soils. 



• "Climatic ami Geological Influence on the Flora of New South Wales.' 

 By R. H. Camljage. Report Aust. Assoc. Advt. of Science, 1907, p. 476. 



