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Show 1867.] DR. J. E. GRAY ON SPONGES. 495 The two latter are Zoophytaria, and not sponges. The arrangement is based:-" E solidarum natura ordines, e contextura genera, e cseteris characteribus species et varietas." Almost all the species mentioned as belonging to the genera are new and not described in thi3 paper; so that it is impossible to determine what they are except for such persons as have specimens named by the author. When a described species is named it is quoted after the genus in the above extract. In the ' Isis,' 1834, Nardo changed the names of the genera, Aplysia to Aplysina and Lrcinia to Hircinia ; and in 1844 he added the genus Spongelia, which is the same as Duseideia of Johnston, 1842. In 1842 Dr. John Hogg (Ann. & Mag. N. H. viii. 1842, p. 5) proposed the following divisions of the "Order S P O N G I A " : - Division I. Spongice subcorneal. The fibres of a somewhat homy substance without any spicula. Sponyia pulchella. Division II. Sponyiee subcorneo-silicece. Fibres composed of a somewhat horny substance with numerous siliceous spicula. No British species. Division III. Spongice subcartilagineo-calcarece. Fibres of somewhat cartilaginous substance, with the spicula calcareous. Spongia compressa, S. botryoides, &c. Division IV. Spongice subcartilagineo-siliceee. Fibres composed of a somewhat cartilaginous substance with siliceous spicula. Spongia tomentosa, S. palmata, and Spongilla fluviatilis. Division V. Spongice subereo-silicece. Fibres of a corky substance with long siliceous spicula. Spongia verrucosa and S. pilosa. "At the Scientific Congress held at Lucca (1843) Dr.Nardo proposed a new classification of the Spongiadce, dividing them into five families, under the names of Corneospongia, Silicospongia, Calcispongia, Corneo-silicospongia, Corneo-calcispongia. These families contain thirty genera."-Morris, Ann. <y Mag. N. H. iv. p. 242, 1849 ; from the Atti della quinta unione degli Scien. Ltal. tenuta in Lucca 1843, p. 436. Hogg, in 'Ann. & Mag. N. H.' viii. p. 190, 1851, remarks, " By comparing these with m y proposed division of the order Spongia*;, published two years before at pages 5 and 6 of the September number, 1841, of the 'Ann. & Mag. Nat. Hist.' (vol. viii.), it will be seen that Dr. Nardo's classification is in most essentials much the same as mine, the only new part appearing to me to be his last and fifth family, which I suppose comprises those species wherein horny fibres combined with calcareous spicula may have been detected." Dr. Bowerbank, in his paper on Spongiadee in the ' Philosophical Transactions' for 1862, p. 1091, gives the following tabular view of the systematic arrangement: - Class PORIFERA. Order I. CALCAREA : Grantia, Leucosolenia, Leuconia, Leucogypsia. Order II. SILICEA. Suborder 1. Spiculo-radiate skeletons: Geo- |
