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Show 1876.] THE SECRETARY O N ADDITIONS T O T H E MENAGERIE. 775 PLATE LXXIX. Chalina verticillata. Fig. 1 represents the sponge, about half its natural size. 2. One of the depresso-spinulate spicula of the skeleton, X 420 linear. 3. A small portion of the scalariform structure of the skeleton, with portions of the interstitial membrane, X 123 linear. 4 represents a longitudinal section of a diluvial flint presented to m e by the late Dean Buckland, containing a fossil sponge closely allied to Chalina verticillata, exhibiting a section of the pedicle and the series of verticillate plates of the sponge, very closely resembling the recent sponge, natural size. 5 represents a small specimen of a fossil verticillate sponge, the margins of the plates remaining uncovered, while the intervals between them are filled by the enveloping sponge, natural size. 6. A longitudinal section of a small specimen closely resembling the one represented by figure 5, exhibiting the immature development of the verticillate plates of the sponge and a section of its central column, natural size. 7. A fine specimen of a verticillate fossil sponge, only half of which is completely enveloped longitudinally by the parasitic sponge, natural size. PLATE LXXX. Ophlitospongia fucoidea. Fig. 1 represents the sponge, two thirds its natural size. 2. One of the shortest of the spicula of the skeleton-fibre, X 250 linear. 3. A n average-sized long spiculum of the skeleton-fibres, X 250 linear. 4. A small portion of the skeleton-fibre, exhibiting the great number of the spicula with which they are furnished, and the mode of their disposition, X 80 linear. PLATE LXXXI. Raphiodesma radiosa. Fig. 1 represents the sponge, rather less than half the natural size. 2. The marginal portion of a thin slice of the sponge at right angles to the surface, exhibiting the radiation of the distal terminations of the skeleton-fasciculi, projected through the dermal membrane to form the minute hispidation of the surface, X 61 linear. 3. A small portion of the dermal rete, X 61 linear. 4. One of the rosette-shaped groups of dentato-palmatecl inequianchorate retentive spicula, X 360 linear. 5. A n acuate skeleton-spiculum, X 360 linear. December 5, 1876. Dr. E. Hamilton, V.P., in the Chair. The Secretary read the following report on the additions to the Society's Menagerie during the month of November 1876 :- The registered additions to the Society's Menagerie during the month of November were 85 in number. Of these, 36 were acquired by presentation, 14 by purchase, 4 by exchange, 3 by birth, and 28 were received on deposit. The number of departures during the same period, by death and removals, was 97. 51* |
