There are only six described species world wide with the most recognizable being Tylodina corticalis. Tylodinids possess a limpet-like shell beneath which the animal can entirely withdraw.
The shell is of a flattened conical shape, radially ribbed and ovate but higher than those of Umbraculidae. The body is smooth, bright, yellow, and moderately large.
The broad foot has a deep transverse groove anteriorly and a large rounded tail. There are two pairs of longitudinally slit, enrolled tentacles with the anterior pair connected to form an oral veil. The larger posterior pair is carried high on the head.
The large gill is bipinnate and located on the right side between the mantle and the foot under the shell and is observable.
Tylodinids are only ever found in clean water habitats. They feed on sponges.