- Kingdom: Animalia
- Phylum: Mollusca
- Class: Gastropoda
- Subclass: Heterobranchia
- Order: Nudibranchia
- Suborder: Dexiarchia
- Infraorder: Aeolidida
- Superfamily: Aeolidioidea
- Family: Facelinidae
- Scientific name: Facelina bostoniensis
- Norwegian: rødhodet frynsesnegl
The translucent pale brown or pink body, may reach a length of more than 5 cm. The red pigmented head is characteristic for this species. The oral tentacles are very long, almost half the body length. The rhinophores are lamellated and are white-tipped like the cerata which are loosely organized in clusters. Brownish digestive glands are clearly visible.
Thrives on rocky locations, feeding on hydroids. Can be found on any diveable depth below the tidal zone.
F. bostoniensis may, as the name indicate, be found on both sides of the Atlantic Ocean in addition to western parts of the Mediterranean.