Stolus uniannulatus ( Sluiter, 1914 ) Thandar, 2021

Thandar, Ahmed S., 2021, Nomenclatural changes in some sea cucumbers with the erection of a new genus and description of a Thyone? juvenile (? n. sp.) from the Gulf of California (Echinodermata: Holothuroidea: Dendrochirotida), Zootaxa 5026 (4), pp. 507-526 : 517-518

Stolus uniannulatus ( Sluiter, 1914) n. comb.

Figure 7

Thyone uniannulata Sluiter, 1914: 10 , fig. 3 a, b.

Diagnosis (s ee Sluiter, 1914).

Material examined. ZMUA (H. 2194), northern Java, 6 19 S, 110 50 E, 50 m.

Remarks. This species was assigned to Havelockia by Panning (1949), transferred back to Thyone in his addendum, but currently assigned to Havelockia by WoRMS (529501, accessed 16 June 2021). The writer concurs with Sluiter (1914) that its calcareous ring ( Figure 7A ) is close to that of Stolus sacellus (= S. buccalis ) and surprisingly the specimen also feels as rigid as a young S. buccalis . In addition, there are regular four-holed knobbed buttons/plates in the body wall, resembling those of S. buccalis , although some of them have up to eight holes. In the introvert there are elongated, smooth to spinous perforated plates and some rosettes ( Figure 7B ). In S. buccalis , on the other hand, the introvert possesses multilocular knobbed plates and rosettes. James (1966) describes the introvert deposits in his specimens of S. buccalis as thin smooth buttons. Hence, there are some similarities between S. uniannulatus n. comb. and S. buccalis but they are definitely not conspecific but perhaps congeneric. The structure of the calcareous ring and the presence of knobbed plates in the body wall preclude the inclusion of this species in Havelockia . Hence, the species is here transferred to the genus Stolus without any hesitation.

Figures

FIGURE 7. Stolus uniannulatus (Sluiter, 1914) n. comb. A. Calcareous ring (mid-dorsal); B. Plates and rosettes from the introvert.