Substrate: Tridacna gigas; identified by A. Hancock as 'Cliona labyrinthica', transferred to Aka by Rützler & Stone (1986). 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.; Hancock, Albany (1849) On the excavating powers of certain sponges belonging to the genus Cliona, with descriptions of several new species, and an allied generic form. The Annals and Magazine of Natural History (2)17: 321-348, pls. 12-15 (S. labyrinthicum: pp. 345, Pl. 15 fig. 7). Rützler, Klaus; Stone, Shirley M. (1986) Discovery and significance of Albany Hancock's microscope preparations of excavating sponges (Porifera: Hadromerida: Clionidae). Proceedings of the Biological Cociety Washington 99(4): 658-675 (HMN 4.15.45-4.15.48: p. 663, Fig. 7c).