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

;SPONGIIDA, 463forms compose the main bulk of the skeleton. (2) Long smoothacuate, generally slightly curved, tai")cring gradually to a lino pointsize about 1-1 by -0127 millim. : forming part of longitudinalskoletou-lines of surface-tufts.Hah. Thursday Island and Prince of Wales Channel, TorresStraits, 4-7 fms.Distrihuiion. " African coasts ? " (^Lamarck).As pointed out in speaking of the characters of the ends of thebranches, this form shows considerable variability : as a rule thespecimens are chiefly branched in one plane (fan-like), but in twospecimens branches project from both faces, but they then tend toform fan-shaped fronds parallel to the main frond. The largestspecimen measures 160 millim. (6| inches) high by 160 millim.wide ; the average maximum diameter of the distinct branches(which are cylindrical or somewhat compressed), not that of thel3roade8t but obviously compound branches (which occur commonly),is about 10-12 millim. Five specimens occurred.91. Acanthella, sp.Externally resembling Spongia cardims, Lamarck (Ann. Mus.Hist. Nat. XX. p. 381). When guided by the description alone,1 had referred the present specimen to this species with more confidencethan usual ; but on mounting sections of the probable typespecimen at Paris, I saw that it was a different species. Thepoints in which the description does not quite suit this form are" pedicule cylindrace, tres-dur," the stem having apparently beenflatfish, and, though stiff", not inflexible ; and " coulour d'un blancgrisatre," whereas this (in spirit) is flesh- colour. The ridges runlongitudinally up and down the sponge, and are 1 to 3 millim. high,and their free edge is beset with sharp (in spirit flexible) points atintervals of one or two millimetres. Texture tough and flexible,substance compact, surface between inequalities glabrous. It is atrue Acanthella. The spiculation is as follows :—(1) Smooth acuate,slightly curved, tapering gradually to sharp point, about -4 to '6millim. by -0095 millim. (2) Smooth undulating cylindrical withrounded ends, length about -7 millim., diameter just •0063 millim.The species differs from the Adriatic forms A. acuta and obtusa,Schmidt, in the broad explanate form and in the smaller size ofthe spicules, the cylindrical being much shorter and thinner, theacuate much shorter than in those species. The skeleton formsa loose-fibred AxineUa-likG network of spicules, imbedded in adense, transparent, almost colourless mass of caoutchouc-like consistency,containing nucleoid bodies about -007 to '008 miUim. indiameter.Hab. Prince of Wales Channel, Torres Straits, 7 fms.A single specimen in spirit, 35 miUim. (If inch) high by 29miUim. across.