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Show 32 MR. HOLDSWORTH ON A RARE CEYLONESE SPONGE. [Jan. /, Fig. 2 represents the outer or inhalant gurf.ico of the sponge, with the remaining portion of its short pedicel. For its anatomical structure see Plate VI. fig. 7. PLATE VI. Dysidea conica. Fig. 1. The type specimen, natural size. Isodictya Donnani. Fig. 2 represents the type specimen, natural size. Fig. 3. A section, at right angles to the dermal surface, exhibiting the skeleton-reticulations and the interstitial membranes and their spicula, magnified 80 linear. Fig. 4. One of the very small acuate spicula from the dermal membrane, magnified 250 linear. Fig. 5. A full-sized skeleton-spiculum, magnified 250 linear. Fig. 6. One of the smaller skeleton-spicula from the interstitial membranes, magnified 250 linear. Spongionella Holdsworthii. Fig. 7 represents a small portion of the keratose skeleton of the sponge from the thinnest part of the distill margin, magnified 80 linear. PLATE VII. Haliphysema tubulatum. Fig. 1 represents the type specimen, natural size. Fig. 2. The distal portion of one of the skeleton-tubuli and its numerous ska leton- and defensive spicula, with the remains of, apparently, the skin of a minute annelid at a, and a small portion of the interstitial spicula at b: magnified 80 linear. Fig. 3. Portions of two of the skeleton-tubuli from near the middle of their length, showing their loose and tortuous course, and their interior structure through longitudinal sections of the tubuli: magnified 80 linear. Fig. 4. One of the largest skeleton- and defensive spicula, magnified 150 linear. Fig. 5. A small-sized skeleton- and defensive spiculum, magnified 150 linear. Fig. 6. T w o of the small subfleeto-attenuato-acuate incipiently spinous defensive spicula, magnified 150 linear. 3. Note on the Occurrence of Xenospongia pateUiformis, Gray, on the Coast of Ceylon. By E. W . H. H O L D S - W O R T H , F.L.S., F.Z.S. [Eeceived January 7, 1873.] This curious form of sponge was described and figured by Dr. Gray in the 'Proceedings' of this Society in 1858, p. 229, pl. xii., from two dried specimens received from Torres Straits ; and, so far as I can discover, no other locality was known for it until I fortunately met with a single young example on the Ceylon pearl-bank. This specimen was obtained from a depth of about 8 fathoms, on a sandy part of the bank ; and, knowing that an opportunity of examining this sponge in as nearly as possible its natural condition was desired at home, I at once put it in spirit, and on my return to England placed it in the hands of Dr. Gray. |