Gastropteridae

Gastropteridae, the bat-winged slugs, is a family of sea slugs, gastropod molluscs in the superfamily Philinoidea of the clade Cephalaspidea, the headshield slugs and bubble snails. The greatest diversity of these colourful small slugs is in the tropical and sub-tropical Indo-Pacific region.

==Description== Gastropteridae is a fairly diverse family containing four genera and thirty-three described species. Adults have an internal reduced shell or no shell at all. The body is fairly short, usually under in length, but exceptionally up to . Compared to the closely related philinids and the aglajids, the mantle cavity is small, and the gills are located further forward, in an exposed position. In most species, the hind end of the headshield is narrowed, raised and curved forward, sometimes being further forward than the front edge of the head. A radula is present, but no jaws. These slugs are mostly brightly coloured and distinctively patterned.