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

;414 COLLECTIONS FKOM ilEL.VNESIA.into the sponge, agrees fairly with this species. Sponge 30 millim.long, 20 millim. high, 10 millim. in greatest thickness. Themain-skeleton lines are somewhat more abundantly spicular.Eah. The first specimen, Port Curtis, Queensland, 11 fms. ; thelatter specimen. Port Darwin.49. Pellina eusiphonia. (Plate XLI. fig. x.)Massive, sessile, horizontal in growth. Surface even, smooth.Yents formed by prominent thin-walled tubes, 3 to 4 millim. indiameter, ranging in length up to 12 millim., numerous, aggregatedon upper surface of sponge, anastomosing with each other ; thicknessof wall about '2 millim. Texture in spirit—basal portion firm, ratherbrittle ; of vents soft, very yielding ; colour in spirit dull pinkishbrown. Main skeleton—no visible horny matter, spicules looselyaggregated in fibres ;primary fibres vertical to surface, '28 to•42 millim. apart, 3 to 5 spicules broad ; secondary fibres approximatelyvertical to primaries, about '2'6 to '42 millim. apart, 2 to 5spicules broad. Dermal skeleton composed of long subparallelspiculo-fibres, rather compact, without visible horny material, 3 to10 spicules broad, '53 to '7 millim. apart ; the intermediate spacesare occupied by an irregular 1-2-spicular network. Subjacentsarcode transparent, pale brown; that of dermis almost colourless,pinkish. Spicules smooth acerate, tapering to moderately sharppoints from within about two diameters of ends ; size -33 by '0125to -019 millim.Hab. Port Darwin, between tide-marks ; bottom rock andsand.The specimen is an irregularly flattened mass, 75 millim. (3 inches)long, 35 millim. broad, 20 millim. in greatest thickness, and involvesseveral stones in its substance. The peculiar arrangement of theexcretory tubes distinguishes it from any species which I canfind described. In the allied form Pdlina semituhulosa, Lieberklihn(Schmidt, Adr. Meer. p. 75 ; Atl. Geb. p. 41), perhaps themost nearly related described species, the spicules taper very graduallyto sharp points, as in Amorpluna paiiicea, Johnston, andmeasure "38 to '44 by -01 millim., and no true vent-tubes seem tobe formed either in this or in the other species referred to Pellinaby Schmidt.50. Protoschmidtia hispidula. (Plate XLI. figs. ^,p'.)Erect, lobose, nodular, the subcylindrical lobes have a slighttendency to branch sideways and a strong tendency to anastomoselobes about 4 to 6 millim. in diameter. Growth bushy (i. e. inmore than one plane). Surface beset with a velvet-like pile of finehair-like points, -5 to 1 millim. apart and about "25 to -75 millim.high ; between points, leathery and glabrous. Vents '? Texturein spirit elastic and fairly compressible, tough ; colour dark reddishbrown. Main skeleton consisting of spiculo-fibre 4 to 6 spiculesbroad, closely but not firmly united ; numerous short parallel