a taxonomic view lumping the families Calmidae, Tergipedidae, Eubranchidae, Cuthonidae, Trinchesiidae and (implicitly by including their type species) Cuthonellidae, Murmaniidae, Abronicidae. Korshunova et al. (2017) consider those as distinct but produce a phylogenetic hypothesis (p. 78) in which they all belong to the same clade; therefore the discrepancy stems from ranking rather than from assumed relationships.