Substrate: Tridacna gigas; Sampled by A. Hancock (?), but overlooked by A. Hancock and Rützler & Stone (1986). Forms part of the samle material of the holotype of S. labyrinthicum. All measurements are of mature, fully formed oxeas (presumably from the endosome) to allow statistical comparison with other samples. Measurements conducted by C. Schönberg on photographs of holotype slide preparations provided by K. Rützler. Data are sorted vertically by spicule width.