Thyonina bijui n. sp. Figure 2

Diagnosis. A small, barrel-shaped species, about 20 mm in length. Colour in alcohol greyish-black to greyishwhite, live colouration reddish-brown. Anal teeth absent, anal papillae present. Tube feet scattered, dorsally papilliform. Tentacles nine (?10), in 7 + 2 arrangement, blackish. Calcareous ring with fused radial and interradial plates, posterior processes of radial plates longer than height of ring, all arising from more or less same level, both ring and processes subdivided. Polian vesicle and stone canal single; madreporite dicotyledonous. Ossicles of body wall as slender, curved, smooth rods expanded and digitated at ends with one or more holes. Ossicles of tube feet similar; end-plates typical of type species. Tentacle ossicles comprise slender rods, rosette-like rods and minute mulberry-like rosettes. Introvert with rosettes similar to those of tentacles and tables.

Etymology. This species is named after one of its collectors, Dr Biju Kumar, of the Department of Aquatic Biology & Fisheries, University of Kerala (DABFUK), India, for allowing me to examine the materials in his museum collections.

Holotype. DABFUK ECH HO 17. Vizhinjam, Kerala State, India (Arabian Sea), SCUBA gear, 2 m., 02 March 2013, collected by Biju Kumar and Deepa Pillai.

Paratype. DABFUK ECH HO 18. Same data as holotype.