BY R. H. CAMBAGE. 391 



After investigating the various methods of distribution, and 

 having in view the isolated occurrence of Casuarina stricta along 

 the east coast of New South Wales, the suggestion that it formed 

 part of the latest flora on the present continental shelf before 

 its final submergence, seems to me less open to destructive criticism 

 than any other put forward. Such a conclusion is supported by 

 an inspection of the She-oaks now growing on the narrow sloping 

 strip of Narrabeen formation near Otford and Stanwell Park. 

 Here C. stricta may be seen creeping up to the foot of the 

 Hawkesbury Sandstone hills, but going no further, its place being 

 then taken by G. suberosa Ott. & Dietr. The contemplation of 

 this patient though persistent progression, especially in the 

 light of our geological knowledge of the past history of this 

 coastal area, suggests that the species has worked its way up 

 from the south along the old land-surface where the formation 

 was found suitable, and on reaching the sandstone, quietly awaited 

 its erosion, in exactly the same way as we find it doing to-day. 



I am much indebted to Mr. W. S. Dun, Palaeontologist, Mines 

 Department, for references to literature bearing on the subject 

 matter of this paper. 



EXPLANATION OF PLATES XII.-XIIL 



Plate xii. 

 Casuarina stricta Ait. , on Narrabeen Shale Formation; Otford to Stanwel 

 Park, N.S.W. 



Plate xiii. 



Map showing the 100-fathom line on the Coast of South-East Australia. 



CENSUS MUSCORUM AUSTRALIENSIUM. 



A CLASSIFIED Catalogue of the Frondose Mosses of Australia 

 AND Tasmania, collated from available Publications and 

 Herbaria Records, by the Rev. W. Walter Watts and 

 Thomas Whitelegge, F.R.M.S. 



Part II. 



(To be issued separately as a Supplement to Part 4 of this Volume). 



