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PROVISIONAL AID TO THE STUDY OP THE 

 TASMANIAN MOLLUSCA. 



By E. M. Johnston, P.L.S. 



The student of Conchology in Tasmania labours under 

 many disadvantages, owing to the circumstance that the 

 descriptions of the various species inhabiting our waters are 

 scattered widely in various publications of Europe and 

 America, while nearly half of the number of the principal type 

 species are deposited in foreign museums, and are therefore 

 inaccessible for purposes of reference to local students. 



Before we can rest satisfied with the existing classification 

 of many species there is much careful work to be done ; for it 

 is well known that the specific descriptions of the earlier 

 distinguished collectors who accompanied expeditions to our 

 seas, are often too meagre to satisfactorily distinguish or 

 separate them from many allied distinct species subsequently 

 discovered. Such accidental collections, too, very naturally 

 contain many forms belonging to widely variable species, and 

 the individuals, of necessity taken by them as types, do not 

 always present the most suitable characters which would serve 

 to distinguish the central type of a widely variable species, 

 and hence the local observer, unable to refer to original types 

 described, is often puzzled or uncertain in his determinations. 



It would be well, therefore, to follow the example of 

 New Zealand, in making up a duplicate collection of our 

 shells as complete as possible, and thereafter submit one of 

 them to a well-known European authority like Ed. Von 

 Martins, who would critically examine and compare them 

 "with original types in European collections, and submit 

 a critical report for the guidance of local workers. Such 

 a course has already been adopted by New Zealand under 

 the guidance of Professor Button, one of the ablest 

 authorities, and certainly one of the most energetic 

 naturalists in Australasia ; an example which Tasmania 

 Would do well to follow. If Messrs. Legrand, Petterd and 

 Peddome, who have so ably worked in this branch of science 

 ln Tasmania, and who possess the best local collections, were 

 to engage in a work of this kind under the auspices of the 

 Poyal Society of Tasmania, I am satisfied that the very best 

 results would be attained, and we would then prepare the way 

 for the publication of a work on Tasmanian Mollusca that we 

 could place thorough dependence upon. 



It will be observed that although the whole of the 716 



