261 



Failing evidence in support of its western origin, it 

 appears reasonable, therefore, to conclude, tentatively, 

 that : — 



1. Tlie specimen was derived from the group of islands 

 stated by Willey as its home. 



2. It migrated thence to the Australian coast, and then 

 southwards along the Notonectian current. 



3. Its further passage from the Tasman Sea was accom- 

 plished during the summer period of prevailing easterlies, 

 its final stages being assisted by the westerly shore currents 

 set up by the eddy in the Great Australian Bight. 



ACKNOAVLEDGMENTS . 



The writer is indebted to the Government Geologist (Mr. 

 X. K. Ward, B.E.) for permission to reproduce the block 

 depicting the trend of ocean currents on the Australian coast ; 

 to Mr. C. Hedley for references to Nautilus occurrences on the 

 New South Wales coast; and to Mr. E. R. Waite, Director of 

 the South Australian Museum, for the reference to the work of 

 Dr. Arthur Willey. 



References. 



1. 1879. Tryon: Man. Conch., 1st Ser., vol. i., p. 215. 



2. 1880. Woodward: Man. Mollusca, p. 188. 



3. 1906. Pelseneer : A Treatise on Zoology, ed E. Ray 



Lankester, pt. v., Mollusca, p. 333. 



4. 1902. Willey: Zoological Results, p. 745. 



5. 1843. Menke: Moll. Nov. Holl., p. 5. 



6. 1851. Milligan: Pap. Proc. Roy. Soc. V.D.L., vol. i., 



p. 292. 



7. 1877. Angas: Proc. Zool. Soc. Lond., 1877, p. 178. 



8. 1877. Brazier: Proc. Linn. Soc. N.S. Wales, vol. ii., 



p. 143. 



9. 1894. Hedley: Proc. Linn. Soc. N.S. Wales, vol. xviii., 



p. 239. 



10. 1897. Cox: Nautilus, vol. xi., p. 43. 



11. 1902. Willey: Loc. cit., p. 808. 



12. 1899. Waite: Aust. Mus. Mem., iv., p. 16. 



13. 1910. Hedley: Proc. Linn. Soc. N.S. Wales, vol. xxxv., 



p. 10. 



14. 1915. Dannevig : Biol. Res. "Endeavour," vol. iii., 



p. 342. 



15. 1910. Hedley: Loc. cit., p. 9. 



16. 1904. Dannevig: N.S. Wales Votes Proc. Leg. Ass., 



1903, p. 56. 



17. 1913. Ward: Geol. Sur. S. Austr., Bull, ii., p. 25. 



