There is sometimes an additional white or yellow line at the margin, and a pair of longitudinal orangish bands may be present near the midline of the headshield.

[2] Philinopsis speciosa has a widespread distribution in the tropical Indo-Pacific region, its range extending from the east coast of Africa and the Red Sea to Japan, Hawaii and New Caledonia.

It is found on the lower shore and the subtidal zone, on sandy and clay bottoms and among seaweed, at depths down to about 20 m (66 ft).

[2] Philinopsis speciosa is a hermaphrodite; two or more individuals form a circle or a short chain.

The white eggs are wrapped in a thin layer of mucus and this strand is wound around the slug's head in a tangled cylinder.