CONTRIBUTIONS TO A REVISION OF THE RECENT 
RISSOID4Z OF AUSTRALIA. 
By Proressor Rautpy Tare. 
[Read September 5, 1899. ] 
CoNTENTS : 
I. Introductory Remarks. 
IT. Classified List of Rissoie. 
III. Classified List of Rissoine. 
IV. Descriptive Notes on South Australian Rissoine (including 
diagnoses of new species ). 
I. INTRODUCTORY REMARKS. 
By way of apology for the fragmentary character of this essay 
I would explain—Firstly, that the large amount of South Aus- 
tralian material which I have accumulated in the last twenty 
years should no longer remain unrecorded, more especially that 
I have now elaborated our recent species in conjunction with 
those of the Older Tertiary of Australia; secondly, in the 
endeavour to bring the Australian species into an alignment with 
the subordinate groups of each genus, and thus indicate a closer 
affinity znter se, I have found it necessary to make considerable 
emendations of nomenclature, and in view of the increasing com- 
petition (which I am extremely glad to note) among Australian 
conchologists, I think it desirable to record my investigations 
without delay. Though the chapter on Rissoiz is, in the main, 
a rectification of nomenclature, yet the jackal-like conduct therein 
exhibited is a consequence rather than an incentive to play such 
a role. 
The family Rissoide is represented in Australian waters by 
two genera only, Aissoia and Aissowna, viewed in their widest 
acceptation. Prior to the publication of the “Mollusca of the 
Novara Expedition,” very few species of the family had been 
recorded for Australia. Since then the chief contributions are 
those by Tenison-Woods on the Tasmanian species, and by 
Watson on those collected by the Challenger Expedition. 
As indicating the rapid gain of species in the family, I may 
refer by way of illustration to the growth of our knowledge of 
the South Australian contingent. The first provincial list of 
marine shells by Angas in 1865 contains only one species of the 
family (Rissoina D’Orbignyi); in 1880 the same conchologist 
