The phylum Mollusca contains around 112,000 described species. They range from minute snails and slugs to large organisms such as octopus, which are among the most neurologically-advanced invertebrates. Two mollusc groups, bivalves and gastropods, also contain freshwater species. Gastropods have representatives that live on land: the land snails and slugs.
Peloparion iridis HELICARIONIDAE Iridescent Semi-slug
This semi-slug has a rudimentary, small, flattened semi-shell with a diameter of about 8-10mm, the animal length about 20mm. The animal's surface has... 
Triboniophorus graeffei Humbert, 1863 ATHORACOPHORIDAE Red Triangle Slug
In the picture you will see two very handsome native Red-Triangle Slugs in a garden in The Gap after recent rain. They appear to be "getting it on".