A velvety black, primitive slug. It has a wide head used like a plough to push through sediment. Due to the fact it is often covered with sticky mucous it is quite often also covered in sand , seaweed and other detritus. It has two flaps, one on either side of the body which curl over the back of the animal. The skin is covered with tiny hairs (cilia) which give it, its velvety look and feel.

Usually found crawling on or burrowed under the mud, but can be found in large numbers on coralline algae covered rocks. It is found from mid-low tide down to the subtidal.

It is a predator of worms both bristle and ribbon worms.

It has a remnant ear shaped internal shell.

Photo Credit: Rod Morris. Photos available from www.rodmorris.co.nz