* Verconia cf. hongkongiensis (Rudman, 1990) Figure 11K

Material examined.

One specimen 6 mm, CB; one specimen 4 mm, TW.

Ecology.

Observed under dead fungiid coral skeleton and rubble in shallow coral reef. Depth 3-8 m.

Distribution.

Verconia hongkongiensis is known from Japan and Hong Kong (Gosliner et al. 2008, 2018). The present Verconia cf. hongkongiensis is a first record for Thai waters.

Remarks.

Initially recorded as Hypselodoris bullockii (Collingwood, 1881) from a single small specimen by Mehrotra and Scott (2016), further observations have concluded that the species from Koh Tao is not H. bullockii but one superficially resembling Verconia hongkongiensis (Rudman 1990). Similarities between the two species are the thin marginal white line and pale variations in colour of the dorsum. However, rather than reddish tips, gills appear to be uniformly red (more orange in some specimens) and rhinophores appear pigmented throughout, basally red, sometimes with a paler median band, ending in red/orange tips, with all individuals recorded from Koh Tao being smaller than 6 mm.