Molluscs belong to the phylum Mollusca:
https://en.wikipedia.org/wiki/Mollusca
The Australian Freshwater Mollusc Lucid key:
https://keys.lucidcentral.org/keys/v3/freshwater_molluscs/
A book reference:- "Australian Land Snails", Volume 1 and 2, by John Stanisic, the "Snail Whisperer".
No sightings currently exist.