Subfamily Tritoniinae Lamarck, 1809 Zoobank registration: urn:lsid:zoobank.org:act: 1EE29562- 18DF-41B2-920F-412511CFC43C. Diagnosis: True stomach plates absent. ODG complex holohepatic. Genera included in this study: Tritonia, Candiella (see diagnosis below), Marianina, Myrella (see diagnosis below), Tochuina, Tritonicula, Tritonidoxa, Tritoniella and Tritoniopsis. Remarks: The absence of true stomach plates is considered a plesiomorphy within Tritoniidae, according to the basal position of Pleurobranchidae in our phylogenetic analyses. The term ‘true stomach plates’ is used in this study to differ these structures from other type of cuticular structure, homologous to the stomach plates of marioniids, known as cuticular folds. Cuticular folds are longitudinal folds covered by a thin cuticular layer derived from the cuticular lining of the stomach. Unlike stomach plates, the cuticular folds have a single continuous cuticular layer along their entire length and are not individually detachable (MacFarland 1966). These structures are present in Tochuina (MacFarland 1966), Tritoniella (Wägele 1989), Marianina (Odhner 1963), Tritonia festiva (MacFarland 1966), Tritonia exsulans (MacFarland 1966) and Tritonia odhneri Er. Marcus, 1959 (Schrödl 2003).

Published as part of Silva, Felipe De Vasconcelos, Pola, Marta & Cervera, Juan Lucas, 2023, A stomach plate to divide them all: a phylogenetic reassessment of the family Tritoniidae (Nudibranchia: Cladobranchia), pp. 445-476 in Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) (Zool. J. Linn. Soc.) 199 (2) on pages 459-462, DOI: 10.1093/zoolinnean/zlad013, http://zenodo.org/record/8432389