Umbraculida are the umbrella slugs: heterobranchs with a flat, limpet-like external shell sitting on top of a bulky body. The group includes Umbraculum and Tylodina (Tylodinidae), which feeds on yellow Aplysina sponges and takes on their colour.
◎Identification
A shallow, cap-like external shell covering the back (like a limpet), with the body and foot projecting around it; rolled rhinophores and a gill on the right side under the shell.
