94 DISCUSSION ON THE SHELL-MOUNDS AT SEAFORD. 



flints, and occasionally split bones of the wallaby. Over 150 

 chipped flints had been collected by him from these deposits 

 near Hobart, and a very large number had recently been sent 

 to him, collected by Mr. John Morrisby on the borders of 

 Pipeclay Lagoon, South Arm. 



He stated also that he had recently received a communica- 

 tion from Mr. Mitchell, of Lisdillon, who tried upon the 

 basis of the extent of these shell deposits to make some esti- 

 mate as to the length of time during which the Island was 

 occupied by the last Tasmanian race. Mr. Johnston stated 

 that an estimate formed in this way would be very unsatis- 

 factory, as the kitchen middens are formed for the most part 

 on the marginal boundaries of our seas and estuaries, and are 

 constantly being encroached upon by the great invader, the 

 sea. It is evident therefore that the horizontal encroachment 

 of the sea would have destroyed the very earliest deposits, 

 supposing them to have existed. It is almost certain from 

 ethnological considerations that the Tasmanian Race must 

 have existed in Tasmania for a very long period, for otherwise 

 how can we account for the marked racial type as compared 

 with the natives of the Australian mainland and elsewhere. 



