This nudibranch is widespread in the central ocean basins, associated with drifting weed such as Sargassum bacciferum. It is green or brown in colour with scattered white patches. There are two pairs of lateral lobes, which are flattened and bear small branching gills on their upper sides. The large rhinophore sheaths surround lamellate rhinophores and have a flap on their posterior surfaces. The whole body is irregular in outline providing good camouflage amongst floating Sargassum. The animal can swim upwards by flexing its body vigorously, an important ability for a nudibranch which drifts about the oceans.