Report on the zoological collections made in the Indo-Pacific Ocean ...

392 COLLECTIONS PROM MELANESIA.granules, lying in a diffusely stained subtransparent matrix of thesame colour, but paler. A transparent membrane, consisting of analmost colourless matrix, containing few purple granules, appears toinvest the fibre,Hab. Thursday Island, Torres Straits, 4-5 fms. ; bottom sand, orsand and rock.Distribution. " Indian Ocean " (Pallas).Obs, In many particulars this species recalls Aplysina purpurea ofCarter, but appears to differ fundamentally in the distinctness, largesize, and non-multiplicity of the fibres ; whereas in that species theaxes of the conuli and the skeleton generally consist of aggregatedmasses of fine fibrils. If Hyatt's species is really like lantheUaJiomei, with which he compares it, it cannot be this sponge, as itwould be of flattened growth ; but he appears to be uncertain onthe point.If one of the dermal cones, with the surrounding membranes, istreated with a strong solution of caustic potash, a dark brownishyellowcolouring-matter is dissolved out, thereby differing fromthat of lantheUa, which is said to be violet iinder similar circumstances(Gray, Proc. Zool. Soc. 1869, p. 50) ; nothing of the tissuesis left but a branched fibre or two and some flocculent matter ;therefore the only truly fibrous structures here are the terminaltwigs of the skeleton.The wall of the main skeleton-fibre of this species is much thickerthan in most ApJijsina', and its axial substance is not granular.20. lanthella flabelliformis.Spongia flabelliformis, Pallas, Blench. Zooph. p. 380.lauthella flabelliformis, Gray, P. Z. S. 1869, p. 50.A specimen in spirit, somewhat imperfect, and not showing anyof those exfoliations of the lateral surfaces which specimens commonlyexhibit.Hab. Port Darwin, 7-12 fms. ; bottom sand.Distribution. Indian Ocean (Pallas); " Australia " (G-'ra^/).CHALINID^.In this family must now be included some forms with minuteflesh-spicules. Homoeoclictya, Ehlers, is the earliest discovered caseof this combination ; and I am able to add another, in a new genus,Toxochalina, which possesses fine tricurvates scattered in the sarcode.I have relegated lilnzoclialina to the Desraacidinida3 for reasons givenbelow (family Desmacidinidse). I have also given reasons for abelief that Platyclmlina, Ehlers, is a Ceratoso sponge (see Euspongia,supra).The fact cannot be ignored that the genus Toxochalina, characterizedbelow, runs counter to the plan of classification hitherto