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ON THE NATURALISED FORMS OF LAND AND 

 FRESH-WATER MOLLUSCA IN AUSTRALIA. 



By Chas. T. Musson, F.L.S. 



Having been fortunate enough during the past year to get 

 together examples of several imported slugs, it may prove of some 

 interest to give a short account of the same, as well as of some 

 shell-bearing forms that have also found their way to these 

 southern climes. 



Colonization of mollusca has been, along with the distribution 

 of other organisms, constantly going on. We cannot claim 

 for our molluscan friends, however, that they have themselves 

 acted other than passively in the matter, except in cases where 

 self-preservation may cause certain efforts to be put forth for a 

 certain purpose ; every instinct then asserts itself, no doubt, 

 endeavouring to preserve that life, which is dear even to the 

 crawling snail, 



A long paper might be written upon those methods in nature, 

 either detected or suspected, through which the land and fresh- 

 water mollusca are or may Ije distributed. 



In these few remarks I do not wish to call special attention to 

 the diverse ways in which this might be effected, or the means by 

 which we have received what are most popularly known as 

 intolerable garden pests. 



No doubt, in the case of most of the species now to be 

 considered, the agency of man has, either designedly or involun- 

 tarily, been the means by which our imported snails came to take 

 up their residence in Australasia. 



Man has, in time past, for food purposes, and acting with 

 forethought, in different countries exported and imported snails ; 



