Wikipedia
Runcinidae
Runcinidae is a family of medium-sized sea slugs, marine opisthobranch gastropod mollusks. They are headshield slugs, in the clade Cephalaspidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
This family has no subfamilies according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005.