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

.colour;464 COLLECTIONS FROM MELANESIA.LEUCOPHL(EUS.Carter, Ann. ^ Mag. N. II. 1883, xii. p. 323.92. Leucophloeus fenestratus. (Tlate XLII. fig. s.)Massive, suberect, terminating above in thin edges, on each,sideof which open wide pouch-like vent-cavities, which also open to thosurface laterally by rounded apertures. Surface minutely undulating,but glabrous. Texture in spirit rather tough, compressible, softdull greyish brown. Main skeleton composed of irregular, veryloose tracts of spicules, 3 to 10 spicules broad, extending in variousdirections and lying at various angles ; the dermis is supportedby some closely set subvertical tracts of similar character lyingbetween the subcortical crypts. Dermal skeleton composed of veryloose and irregular tracts or aggregated masses of spicules intercrossingso as to form an almost continuous sheet, in the intervalsof which are placed the pores, Sarcode pale brown, subtransparent.Spicule smooth straight, or almost straight acuate, tapering graduallyfrom centre to moderately sharp point, and from centregradually to well-rounded undilated base, which has, however, onlyabout half the diameter of the centre of the shaft ; size of spicule•5 to -8 by -019 to -022 miUim.Hah. Port Darwin, 8-12 fms. ; bottom sand and mud.The height of the single specimen is 38 millim., greatest diameter(at base) 20 millim. ; it forms an irregular, elongated i^yramid, withthe apex flattened out and somewhat twisted. In size and shapeof the spicules the species resembles Ihjinenkicidon crustula. Bowerbank(Mon. Brit. Spong. ii. p. 185), from the British Seas, which is,however, massive or mammillated and, owing to the inferior diameter(•012 millim.) of the spicule, shows the slenderness of the basal endmuch less distinctly. It is nearly related to L. massalis, Carter(I. c), from ^y. Australia, but is darker in colour, is less distinctlypenicillate, and has the spicule rather larger.Leucophloeus fenestratus, var.(Plate XLIII. fig. g.)A dry, upright, flattened specimen, which has grown around aHydroid bush, appears closely allied to the above species. It appearsto have formed part of a long wall-liko mass,' 70 millim. (2^ inches)high and 15-20 millim. thick. Like it, it is surmounted Ijy pyramidalprocesses, and is traversed from the upper surface downwardsby large cloacal spaces. Colour white, with a tinge of green. Thespicules differ from those of the tjqiical form in measuring•9 by '032 millim. : as, however, a small series of specimens of thisspecies from the western part of the Indian Ocean (see Part II.of this work) includes within itself as great a variation in thisrespect as is shown by these two Australian specimens, I do notassign distinct varietal names to these two, at first sight, verydistinct Australian specimens,Hab. Arafura Sea, 32-36 fms. ; bottom sand, mud, and shells.