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

;8P0NG1IDA. 455•11 by -0095 millim. ; and thus gives a wider range to the possiblevariation in the sizes of spicules within the limits of a species.The only locality hitherto known with certainty was N.W.Australia.Ilah. Port Curtis, Queensland (apparently from beach).Distribution. N.W. Australia (liidleij).Obs. This specimen most forcibly illustrates some remarks whichI published in the Journal ' of the Linnean Society ' (Zool. xv.p. 149), on the possible intrusion of extraneous spicules into sponges.The dermis contains, in fascicles and scattered, large numbers of aslender acuate form, which is wholly alien to the sponge, but whoseappearance and position are so natural that I found it difficult toestabhsh this fact. Ee-examination of the slide referred to by me(I.e. supra, p. 495) as representing a specimen of this species, probablyfrom Freemantle, !S.W. Australia, has satisfied me that it isnot referable to the species, but to one of those Ecliinodictya whichpossess fine acuate spicules in addition to the skeleton acerate (seeabove) ; the fine acuates M'ere at first regarded by me as adventitious.84. Echinodictyum costiferum. (Platb XLII. fig. r.)? Spongia costifera, Lamarck, Ann. Mtis. Hist, Nat. xx. p. 432.Normally probably turbinate, forming an open cup ; wall about 3to 8 millim, thick, undulating. Inner surface uneven, beset at intervalsof about 5 millim. with pointed monticular eminences, about3 millim. high ; outer surface proliferating into subdivided ridgelikeor monticular eminences, each beset with several sharp pointsthese eminences are about 5 to 8 millim. high. Surface betweeneminences on both sides cancellated and more or less cavernous indry state. Texture in dry state very harsh to touch, hard, brittle ;colour pale buff'-yellow. Main skeleton :—spiculo-fibre compact,no horny matter apparent, but surrounded by yellow sarcode ; allfibres echinated by the spined spicules ;consists of (i.) a longitudinalseries of stout branching fibres, -032 to -095 millim. thick, runningtowards the free edge of the sponge, and outwards into its surfaceeminences,where they form the sharp points referred to above, and(ii.) an intermediate network composed of meshes varying in shapefrom subrectangular (square or oblong) to oval and round, the anglesalways more or less rounded off, greatest diameter from •00 to•15 millim. ; the deeper fibres bear the slender acuate spicule(No. 2) laid along the surface or projecting at very acute anglesfrom it, sparingly. Dermal skeleton as main skeleton, but spiculeNo. 2 apparently absent.Spicules :—(1)Smooth acerate, slightly bent, tapering to more orless sharp points from about 3 to 5 diameters from ends ; size "22 to ^28by -0079 to.-0095 millim. : forms the skeleton- fibre. (2) Smoothacuate, with weU-rounded base, tapering gradually to fine pointsize ^44 by •005 millim, : on surface of deeper skeleton-fibres.(3) Spined cylindrical, tapering gradually from rounded base to therather coarsely spined free end ; spines distributed all over spicule,