BY R. TATE AND W. L. MAY. 345 



The want of good illustrations of the species diagnosed by the 

 the three authors a'^ove-named, has made it almost impossible to 

 bring the constituents of the Tasmanian molluscan fauna into 

 correlation with those of adjacent provincial areas; consequently, 

 they have, to a large extent, been overlooked by subsequent 

 authors, who, occupying themselves with the adjacent faunas, 

 have imposed different names for the majority of the figured 

 species. 



The diagnoses by Tenison-Woods are for the most part ample; 

 he was apt in grasping the dominant characters, and only in a 

 few instances are generic assignments inaccurate. We cannot 

 speak quite so favourably of Mr. Petterd's work, but his species 

 claim recognition. Mr. Beddome's work is valueless by the in- 

 sufficiency of specific characters and by faulty generic location; 

 but from the circumstance that one of us prepared drawings of 

 his types the task of interpretating his species would have been 

 hopeless. 



Since 1878, the senior author of this "Revised Census " has 

 been occupied in an effort to bring these insufficiently known 

 Tasmanian species into an alignment with better known species 

 inhabiting other parts of the Australian coast, being aided by the 

 gifts of cotypes from the Revs. Tenison-Woods and H. D. Atkinson, 

 Messrs. Petterd and Legrand, besides having had the privilege of 

 the study of other critical species in the collections of Messrs. 

 Petterd, Simson, Beddome, Harrisson and the Rev. T. Hull. 



That the species-names of the shells forwarded to Tryon were 

 in some instances wrong has been made evident, which indicates 

 that the Tasmanian collectors at that time were not agreed in the 

 interpretation of Woods's species; only in a few instances has 

 Tryon indicated the source of his materials. 



The junior author of this essay has Especially studied the type- 

 specimens or reputed types, of many which are in the Hobart 

 Museum, and is thus enabled to establish on a good foundation 

 the authorities for the specific names. 



Wherever possible we shall illustrate all the species which 

 remain untigured; and in this connection we acknowledge our 

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