Designation of a Neotype for the Dwarf Sea Hare Aplysia concava G. B. Sowerby I, 1833, and a Review of the Status of Aplysia norfolkensis G. B. Sowerby II, 1869 (Mollusca: Heterobranchia) Author Nimbs, Matt J. text Records of the Australian Museum 2021 Rec. Aust. Mus. 2021-11-24 73 5 147 151 http://dx.doi.org/10.3853/j.2201-4349.73.2021.1773 journal article 10.3853/j.2201-4349.73.2021.1773 2201-4349 7178118 5F34B436-75B2-4B9E-A06C-16A674B7BD37 Aplysia concava G. B. Sowerby I, 1833 Fig. 1 Sowerby I (1833) described Aplysia concava based on a shell from an unknown location. The type specimen could not be found at the UK Natural History Museum and is likely lost (A. Salvador pers. comm., cited in Golestani et al ., 2019 ; Nimbs & Wilson, 2021 ). In accordance with Article 75.3 of The Code (ICZN 1999), specimen AMS C.574820 collected from Newcastle , NSW, on 14 December 2016 by Stephen D. A. Smith is here designated as neotype for Aplysia concava G. B. Sowerby I, 1833 for the purpose of clarifying the taxonomic status of the species ( Fig. 1 ). Characters that define the neotype and differentiate it from other taxa in the Aplysia parvula s. l. species complex are listed in Nimbs & Wilson (2021) . Although the type locality for Aplysia concava was not specified by Sowerby I , it was listed as “ Australia ” by Sowerby II in 1869. Given the broad geographic scope associated with this putative original type locality, a specimen collected from Newcastle , NSW on the central east Australian coast was selected as a reasonable neotype . The neotype has been lodged with the Australian Museum , Sydney , Australia ( AMS C.574820) .