See text Bulla is a genus of medium to large hermaphrodite sea snails, shelled marine opisthobranch gastropod molluscs.

According to some experts, Bulla is currently the only recent genus in the family Bullidae, which in turn is the only member of the superfamily Bulloidea.

Since little difference exists between the shells and in the morphology of the radular teeth, some uncertainty remains about the exact taxonomy of the species in Bulla.

These snails are mostly nocturnal and can be found on shallow, sandy coasts grazing among sea grasses, feeding primarily on green algae.

In the coastal lagoons and bays of California, the colorful Navanax inermis is a well-known predator of sea slugs, especially Bulla gouldiana, which it envelopes whole.