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

SPONGnDA. 381excretory chambers, separated by comparatively narrow and sheetlikeskeletal trabeculse, with even surfaces, which distinguish Hippospomjia; but on looking at the brief description given by Prof. F.E. Schulze (Zeitsch. wiss. Zool. xxxii. p. (520) of the Adriatic formwhich he has placed under Easponri'ia ojjicinalis, as var. tulmlosa,I saw that he had had a closely similar form before him. It agreeswith our specimen in the long tubes (of much less diameter, however,in the Adriatic tuhulosa than here) and in the absence of sandcoredfibres ; but it appears to want the following striking peculiaritiesof our form :—(1) subglobular form (incrusting in Schulze'sspecimens) ; (2) trabecular structure of main body ; (3) absence ofconuli (they are stated bj' Schulze to occur on the general body ofthe sponge, but in a very well-preserved specimen in absolute alcoholwhich he has liberally presented to the National Collection, I findthem only on some small digitate lobes which spring from the body ;those possibly occurring upon one of the tubes in var. cavernosa areevidently only exceptional) ; (4) approximate equality in stoutnessof fibres throughout (in var. tnhulosa those near the siirface aresaid to be thinner than elsewhere).In a preparation made from Prof. Schulze's specimen I do notnotice a special thinness of the fibres at the surface, but thej' seemto have a slightly greater diameter throughout than in our form.Considering the dry state of this single specimen and the evidentplasticity of form in E. ojjicinalis, I think it best to associate thisform provisionally with that termed by Prof. Schulze var. tnhulosa,feeling that it may be only a mere extreme variation of the speciesin the same direction as that variety, deferring (as I feel bound todo on a question which Prof. Schulze has made so eminently hisown) to Prof. Schulze's judgment in specifically uniting aberrantforms like these with those familiarly known as E. ojjicinalis ; I am,however, induced, from the points of divergence from tuhulosa notedabove, to assign to it a distinct varietal designation.Hah. Torres Straits, 10 fms.Distrihution (of species). Mediterranean (Schulze, &c.).4. Euspongia septosa.? Spongia septosa, Lamarck, Ann. Mtis. Hist. Nat. xx. p. 373.It is possible that Lamarck's species, of which I have access tothe description only, is a Dendrospomiia (H5'att), as its somewhathoneycomb-like surface renders not impossible ; but it seems toresemble a species in this collection, represented by two small specimensin spii'it, of a dark grey colour, each attached to two or morestones, over which they form horizontally expanded lamina? whichrise into subcylindrical lobes 5 to 7 millim. in diameter. The surfaceis broken up by a number of sharp prominent ridges and points1 to 3 millim. high ; the intermediate surface is rough. Primaryskeleton-fibres set approximately at right angles to surfice, thicknessabout •00 millim. ; secondaries approximatelj' vertical to primaries,about •035 to -053 millim. in thickness, forming with some connecting