Ryan Photographic -Onchidiidae- Pulmonate Gastropods
FamilyOnchidiidae
The family Onchidiidae is represented by 84 species in 13 genera. They are unusual in that they are more closely related to land-dwelling air-breathing snails and slugs than they are to the nudibranchs. They are found in shallow water coastal environments, estuaries, mangrove swamps and, even on land.
Onchidium species? Mudflat pulmonate

Onchidium species? Mudflat pulmonate, Sulawesi