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

476 COLLECTIONS FROM MELANESIA.103. Stelletta, sp.Some fragments of a large specimen which has grown oversome coils of Vermetus, not sufficiently complete to be safelydescribedin full. The stellates are minute, and resemble those ofS. purpurea and clavosa, but the arms are somewhat stouter and arenot provided with heads.Hah. Torres Straits, 5-7 fms.STELLETTINOPSIS.Carter, Ann. ^ May. N. H. 1879, iii. p. 348.This genus resembles Tetliyopsis, Stewart, in that the two typicalspecies have a minute bacillar flesh-spicule just such as that of thenew species of Tethyopsis described below ; and if it be, as seemsprobable, a tetractinellid which has undergone abortion of two arms(as in Placina monolophn^ Schulze) of the main spicule, it resemblesTethyopsis further in this tendency to lose the arms of its skeletonspicule(see description of Tethyopsis dissimilis, supra). Eeductionof the triradiate of the latter species by loss of a single arm wouldmake the spiculation (apart from the skeleton-arrangement) essentiallythat of l^tellettinopsis, if the bacillar spicule is regarded asan elongate stellate. The new species is assigned here to Stellettinopsisbecause it differs only from the typical species in the absenceof the bacillar,-—not a point of great importance, if the variationin Geodia as to presence and absence of one or other of the minutespicules is considered.I dedicate this new species to Mr. H. J. Carter, to whom is duethe credit of establishing this genus, and to whom I owe a greatdebt in his constant and ready help.104. Stellettinopsis carteri. (Plate XLIII. figs, n, n.)Pedicellate, on a short cylindrical stalk, passing gradually intoa massive, somewhat flattened upper portion, which shows semidetachedlobes. Surface of upper portion dimjiled and corrugated(somewhat like the Mammalian cerebrum). No visible vents. Texturein spirit soft, but elastic ; colour in spirit dirty white. Surfacebetween the undulations even, but minutely rough. Sarcodecontinuous, without many cavities ; soft, very pale yellow in colour.Main and dermal skeletons consisting of a confused interlacementof the skeleton acerate spicules, not aggregated into fibres or tracts.Spicules:—(1) Skeleton acerate, taperiug to sharp points fromnear the middle ; size 1-0 by -02 millim. (2) Stellate, with veryslight body, and five to ten straight blunt arms of uniform diameter(about -0017 millim.) throughout ; microspined with fine sharppoints, which are most prominent at the tips ; size -05 millim.across arms.Hah. Prince of Wales Channel, Torres Straits, 5-7 fms. ; bottomsand and shells.