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

;spoNGiroA. 61739. Echinonema gracilis. (Plate LIV. figs. I, V .)Erect, very slender, brandling dichotomoiisly and seldom ; branchesgiven off at angles of from aboiit 60° to 90°, cylindrical or irregular,sometimes somewhat flattened, diameter 2 to 5 millim. Surfacesmooth. Vents not apparent. Consistence in spirit soft, elastic,very compressible, rather tough ; colour very dark purplish brown.Main skeleton subrectangular in arrangement ;primary fibres "05to '07 millim. in diameter, pale yellow, almost filled with the skeletonspicule; secondaries -035 to -05 millim. in diameter, containing oneor two series of spicules. Dermal skeleton consisting of radiatingtufts of subspinulate spicules, the bases of the tufts about "25 millim.apart, the points of adjacent tufts crossing each other. Sarcode ofinterior dark yellow, granular ; that of dermis transparent, very palepurple. Spicules :—(1) Subspinulate of skeleton and dermis, straight,shaft smooth, head provided with a few terminal very fine spineshead oval, of about same diameter as middle of shaft, neck slightspicule tapering gradually to sharp point ; size -34 by -012 millim.(2) Acuate, minutely spined on base, straight, tapering gradually tosharp point; size -25 by '014 millim. (in centre of primary fibre).(3) Echinating spined subspinulate, tapering to sharp point from twoor three diameters from end, well spined over head and distal twothirds ; the spines sharp and strong, those on shaft recurvate towardshead ; size of spicule -082 by -013 millim. (4) Trieurvate acerateof sarcode, smooth, middle curve bold ; size '057 by -001 millim.(5) Equianchorate, navicular, shaft slightly curved ; length of spicule•02 millim.Hah. Providence Eeef, Mascarene Islands, 24 fms. ; bottom, sandand dead coral.Several small and more or less imperfect specimens in spirit; thelargest measures 75 millim. (3 inches) in length. In the slenderproportions of the sponge (which gives it the appearance of aRaspailia) and in the weak development of the horny fibre thisspecies stands quite apart from the Australian species as well asfrom the foregoing form.AXINELLID^.Of the four species to be enumerated, one is found also on thesouthern and one on the west northern coasts of Australia. Thevery variable character of the surface of Leucophlcieus proteus is asomewhat unusual manifestation of the polymorphism of Sponges.40. Azinella spiculifera. (Plate LIV. fig. b.)Spongia spiculifera, Lamarch, Ann. Mus, Hist. Nat. xx. p. 449.A specimen in spirit, agreeing well with the fragment in theMuseum which represents Lamarck's species. It consists of two