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

;SPONGIIDA. 611finely hispid surface aud the low irregularlj^ lobate form, togetherwith the spicular characters, they agree closely with the Australianspecimen, but the average diameter of the lobes is somewhat less(about 10 millim,).Hah. Providence Reef, Mascarene Islands, 24 fms.Distribution. Port Darwin.33. Esperia gelatinosa. (Plate LIY. figs./-/"".)Low incrusting masses, frequently involving foreign bodies,occasionally rising into slender lobes. Surface in spirit undulating,glabrous. Consistence tough, elastic, firm. Colour pale greenishgrey or pinkish brown ;general appearance gelatinous, semi-transparent.Main skeleton rather confused in the incrusting specimens ; thevertical lines near the surface being short, broad, loose, andclosely approximated ; in thicker specimens the ordinary Esperiandistinct spiculo-fibres appear at some distance below the surfaceprimaries crossed by more or less numerous detached skeletonspicules.Dermal skeleton composed of confusedly intercrossingspicules not arranged into spiculo-fibrous reticulation. Sarcode verypale yellow, transparent.Spicules: — (1) Skeleton subspinulate ; head oval, slightly butdistinctly demarcated from shaft, about two thirds the maximumdiameter of the latter ; shaft tapering rather abruptly to sharppoint ; size of spicule 'S by '016 millim. (2) Large inequianchorate ;large end moderately broad, about half the total length of the spicule,tubercle long, lower angles of outer palms slightly rounded ; smaUend subtriangular, rather small, pointed below, tubercle small,tongue-shaped, a small reverted margin extending as far as thetubercle in the middle ; size of spicule -06 by -0032 millim. (3) Smallinequianchorate, large end about three fifths the total length ofthe spicule; shaft aud arms weU but gradually curved, tubercleshort ; lesser end very small, not prolonged below into a point; lengthof spicule -019 millim. (4) Bihamate, contort, slender, well curved,sharp-pointed ; size -057 by -002 millim. (5) Trichites in oblongcompact bundles about '02 millim. long and "0063 to -0075 millim.in diameter ; spicules approximately straight. Extremely abundant.Hah. Providence Reef and Providence Island, Mascarene group,19-24 fms. ; bottom, sand or dead coral.The longest lobes are 20-30 millim. long and 3-6 millim. indiameter. In habit, spiculation, and arrangement of skeleton itmuch resembles E. IcBvis, Carter (Ann. & Mag, N. H. 1882, ix. p. 291,pi. xi. fig. 16), from Yenczuela, aud E. pellucida, mihi (Part I., p. 437,of this <strong>Report</strong>) ; but the small inequianchorate here has not theterminal point described by Carter, and the trichites are muchsmaller (-02 miUim. instead of '067 millim. long) ; from E.jiellucidait differs in the small, short, (quadrangular trichite-bundles, in thesmaller size of the anchorates, &c. The species is quite abundant,though no large specimens were found.2r2