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Show 18/3.] DR. J. S. BOWERBANK ON CEYLONESE SPONGES. 25 Fig. 10. One of the small slender acerate spicula of the dermal membrane, magnified 123 linear. Fig. 11. One of the small skeleton-spicula intermingled with the slender acerate spicula of the dermal membrane, magnified 123 linear. Fig. 12. A full-sized skeleton-spiculum, magnified 123 linear. 2. Report on a Collection of Sponges found at Ceylon by E. W . H. Holdsworth, Esq. By J. S. BOWERBANK, F.R.S., F.Z.S., &c. ' (Plates V.-VII.) [Eeceived November 6, 1872.] On the return of Mr. Holdsworth from Ceylon, in 1871, he brought with him a small collection of Sponges which he obtained at the Pearl-banks and from the beach near his house at Aripo, on the north-west side of the island. The total number is 25 specimens ; many of those from the beach were in a condition in which specimens thus* obtained are usually found, either well-washed skeletons, or so much deteriorated as to have destroyed a considerable portion of their softer parts, on which their specific characters frequently depend. I examined the whole of the specimens ; and the following is a list of the genera and the number of species of each :-Chalina 11 specimens, consisting of 7 species ; Spongia 6 specimens, of 3 species ; Stematumenia 2 specimens, of 1 species; Dysidea 2 specimens, of different species ; and 1 species each of the following genera, Halichondria, Desmacidon, Isodictya, Spongionella, and Haliphysemu. The last three of these species and one Dysidea are not only in a fine state of preservation, but they also possess more than the usual degree of interest from the singularities and beauties of their struc- • tural peculiarities, as well as from having been hitherto unknown to science; and I have therefore selected these species for description and illustration. SPONGIONELLA HOLDSWORTHII, Bowerbank. (Plate V.) Sponge cup-shaped, margin entire or lobed; parietes very thin ; pedestal short and stout; surface smooth and even. Oscula simple, rather equally dispersed ; orifices circular, or more or less radiating; pores inconspicuous. Dermal membrane thin and pellucid. Skeleton- primary lines regular, comparatively stout; secondary lines rather irregular, slender. Colour in the living state dark brown, like dirty leather (Mr. Holdsworth). Hab. Nine-fathom line, or western margin of the great Pearl-bank off Aripo, Ceylon (Mr. Holdsworth). Examined in the dried state. I received five specimens of this interesting species of sponge for examination from m y friend Mr. Holdsworth. They were all of nearly the same size as the one represented by figs. 1 & 2, Plate V. |