Large opisthobranch, found feeding on sponges
(mainly a black Cacospongia sp.) with a large
patelliform shell on its dorsum. The shell does
not cover the whole animal but protects its
internal organs. The mollusc is drab in colour
with paler coloured tubercules covering all the
body. Rhinophoral tentacles present as folded
appendages. Size range: up to 80mm. Uncommon.
Specific characteristics:There is probably
only one species of Umbraculum worldwideand is easily distinguished by its umbrella-like
shell, body form and habitat.