A. Adams. Proceedings of the Malacological Society of London, 40(3): 189-210, 11 figs. External links Oskars T.R., Bouchet P. & Malaquias M.A. (2015). A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers. Molecular Phylogenetics and Evolution. 89: 130-150 Euopisthobranchia