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

SPONGHDA. 599deration of the large size of a specimen from Mauritius (probablyfrom deep water) in the National collection : this measures 170 by100 millim. in greatest length and breadth ; the primary fibresproject strongly from the paper-like dermis, and the conuli are 5-10millim. apart ; the fibre shows just the branching arrangementdescribed in 0. colhctrix. The species now to be described agreesremarkably in general characters with the same species, and is alsosufficiently large to be called adult.14. Oligoceras conulosum.Incrusting, strongly flattened from above downwards, forming aleathery crust, but occasionally throwing out flattened, pointed, freelobes from lateral margin ; strongly hirsute above with the veryprominent, slender, and pointed conuli, 1-2 millim. high, 2-4 millim.apart at tips ; terminated by the single or (more rarely) multipleends of primary fibres, which stand out about 1 millim, beyond thedermis. Surface between ends of conuli forming a series of slightlyconcave spaces (in spirit), smooth, glabrous, of leathery appearance.Colour in spirit dull putty-colour to pale grey ; consistence (whenoccupied by Spongiojyhaga) flexible, tough. Main skeleton— primaryfibre occasionally branched at apex, about '17 to "27 millim.in diameter ; axis composed of closely packed foreign bodies, occupyingfrom 1^ to y^^ of the entire diameter : secondary fibres apparentlyabsent. Dermal skeleton composed of irregularly arranged fibres,chiefly straight and parallel to each other, varying in compositionfrom an almost entirely horny to an almost entirely sandy state ;diameter about '14 to '35 millim., meshes about "35 millim. wide ; asmall quantity of free foreign bodies is to be found interspersed inthe intervals between the fibres. Tissues between fibres of mainskeleton also containing a considerable proportion (about one fourth)of free, small, foreign bodies. Horny matter of fibre normally paleamber-yellow, transparent. Parenclayma very pale brown, transparent.ffab. Glorioso Islands, 7-10 fms. ; bottom, sand and coral.A single specimen in spirit, 60 millim. in extreme diameter atbase, 8 millim. in greatest thickness of the same ; the lateral lobe(which seems to have been decumbent) is 30 millim. high, 14 by 4millim. in basal diameter. Tissues infested by a Sponglophaga(Carter)—head oval or subpyriform, long diameter '095 to '013millim., short diameter "006 to -0095 millim. ; filament, diameter•004 to "005 millim.—which has partly destroyed the horny matterof the fibre, and forms sheets in the mesoderm.The apparent total absence of secondary fibres is perhaps due toyouth or the ravages of the parasite : the arrangement of the skeletonis that ascribed by F. E. Schulze to Oligoceras colhctrix, Schulze, fromOligoceras to possess in parts the ordinary reticulate arrangement found inCacospongia, &c. This observation seriously militates against its genericdistinctness.