Sclerothyone Thandar, 1989

Thandar, A. S. & Arumugam, P., 2022, Referral of Thyone neofusus Deichmann, 1941, Thyone adinopoda (Pawson & Miller, 1981 and Havelockia obunca (Lampert, 1885) to the genus Sclerothyone Thandar, 1990, and a replacement name for the preoccupied genus Neothyone Deichmann, 1941 (Echinodermata: Holothuroidea: Dendrochirotida), Zootaxa 5219 (1), pp. 65-71 : 66

Genus Sclerothyone Thandar, 1989

Diagnosis (from Martins & Tavares 2019, amended herein). Tube feet in double rows, restricted to ambulacra, interambulacra mostly naked, or tube feet scattered over body. Calcareous ring compact, non-tubular, posterior processes of radial plates long, entire or subdivided. Body wall tables with regular, oval, four-holed disc, with or without a handle, or large, irregular multilocular disc, also with or without a handle. Spire with pillars separate or fused. Introvert with plates, rods, rosettes and/or tables. Tentacles with rods, plates, rosettes or tables. Tube feet with endplate, supporting tables and plates.

Included species. All genera and species included, except those here dealt with, are tabulated by Martins & Tavares (1998), together with their distribution and ossicle morphology and there is no need to repeat this here, except that Cucumaria nozawai Mitsukuri, 2012 , from Japan, was transferred to Sclerothyone by Thandar (2021) and, in the current paper, Thyone neofusus Deichmann, 1941 from the West Atlantic, Thyone adinopoda Pawson & Miller. 1981 also from the West Atlantic and Havelockia obunca ( Lampert, 1885) from Japan, are also now transferred to this genus as suggested by Arumugam (2011). The inclusion of T. adinopoda was not questioned by Martins & Tavares (2019) but they excluded it from their table and the key. Hence altogether 13 species currently stand in Sclerothyone . The key provided by Martins & Tavares (2019) is here modified to include all the species. The debatable species are discussed below.