BY R. H. CAMBAGE. 389 



Australia, it could only be brought to Otford and Newport from 

 the south; but the prevailing ocean current in the vicinity of 

 these places is from the north. Mr. G. H. Halligan, F.G.S., 

 Hydrographic Surveyor, Public Works Department, who has 

 made a special stud}^ of these currents, writes to me as follows — 

 "It is certain that the N.E. current coming through Bass' 

 Straits, and which would become a northerly current if it skirted 

 the east coast of Australia, never reaches much further north 

 than Twofold Bay, except perhaps as an undercurrent. It seems 

 to me quite impossible that G. stricta can have been conveyed by 

 water from the southern coast as far north as Jervis Bay." It 

 might also be mentioned that near Otford the species is confined 

 to the upper part and sides of the hills, and does not extend to 

 the low land near the ocean. The same remark applies to New- 

 port, though there the sloping hill approaches nearer the ocean 

 at one spot; so that if the seeds were washed ashore the available 

 evidence indicates that they would still have to be carried to the 

 hillside before young plants would grow. 



Looking at the matter from any point of view, it remains 

 difficult to definitely explain the occurrence of this Casuarina at 

 Newport and Otford, though it cannot appeal to one as being 

 the result of accident or coincidence. The suggestion that it 

 may have formed part of the ancient flora and have continued 

 southerly to Victoria partly along the area which now forms the 

 continental shelf seems quite possible and even probable. In 

 view of its suggested antiquity, the question will naturally arise 

 as to why has it not spread across the Hawkesbury Sandstone 

 on to the Wianamatta Shales about 12 to 15 miles away, and 

 which should produce a flora somewhat similar to that of the 

 Narrabeen Shales. Had the distribution been by birds, this 

 would probably have happened long ago. The reason why it is 

 not on the Hawkesbury Sandstone area is probably a geological 

 one. 



A. 0. Seward, M.A., F.G.S.,* quotes Fuchs in reference to the 

 nature of the soil on the character of the vegetation, and in 



* Fossil Plants as Tests of Climate. 1902, p. 42. 



