Embletoniidae Pruvot-Fol 1954

Family Embletoniidae Pruvot-Fol, 1954 Diagnosis: Body very narrow. Notal edge completely reduced. Cerata placed in single row on each side of body. Apical parts of cerata bear single or several cushion-like elevations, and may bear cnidosac-like structures. Oral tentacles absent, oral veil present instead. Rhinophores smooth. Anus pleuroproctic toward acleioproctic. Anterior foot corners absent. Elaborate oral gland present. Masticatory edges of jaws bear a single row of distinct denticles. Radula formula 0.1.0. Central teeth with relatively distinct non-compressed cusp. Distal seminal receptaculum. Vas deferens moderately long, may form distinct prostate adjacent to penis. Massive external permanent penial collar absent. Special supplementary gland or accessory in male part of reproductive system is absent. Penis internal, small, subconical. Genera included: Embletonia Alder and Hancock, 1851. Remarks: The superfamily Embletonioidea, reinstated with the single family Embletoniidae, represents distinctly paedomorphic taxa, comparable to evidently paedomorphic Tenellia proper in the family Trinchesiidae of the superfamily Fionoidea (Korshunova et al. 2022) according to its general body pattern, highly reduced number of cerata and presence of small oral veil instead of developed oral tentacles, and parallel to the independent formation of the partly externally similar, but otherwise completely different family Pseudovermidae (Martynov et al. 2020) from the genuine Aeolidacean superfamily Cumanotoidea (see Synopsis of all Aeolidacean families above; Tables 3, 4). According to the molecular phylogenetic analysis in Martynov et al. (2020) Embletoniidae appear as sister to the family Unidentiidae, whereas according to the phylogeny in Karmeinski et al. (2021) Embletoniidae show a rather unsettled position either basally to all Aeolidacea or within different (though related to Aeolidacea) non-aeolidacean suborder Janolacea. At the same time, previous considerations that Embletoniidae belong to the suborder Dendronotacea, can now be safely excluded. The family Embletoniidae, therefore, is not included in Tables 3 and 4 with a summary of diagnostic characters within aeolidacean superfamilies and families, but included here as an addition to the suborder Aeolidacea.