On the Sponge-fauna of Norway. 241 RJiabdopleura by differences probably ordinal in value, and which in some of its characters and in general appearance resembles the ordinary Phylactolamiata. It is unnecessary to insist on the interest that must attach to such a form should it exist. I trust that this notice may meet the eye of some one who may have the opportunity of searching the locality from which my father's specimen was obtained, and to whom the point to be solved may appear of sufficient importance to warrant a thorough investigation. XXV. — The Sponge fauna of Norway ; a Report on the Rev. A. M. Norman's Collection of Sponges from the Norwegian Coast. By W. J. Sollas, M.A., F.G.S., &c. [Continued from p. 144. J [Plates X., XI., XII.] Order TETRACTINELLIDA, Marshall. Tribe PACHYTRAGIDA, Carter. Group Geodina, Carter (Family Geodiidce, O. Schmidt). Genus 1. Geodia, Lmk. Type G. gibberosa, Lmk. (Pyxitis, Sdt.) 2. Cydonium, Fleming. Type C. zetlandicum, Johnst. (Geodia, auct.) 3. Pachymatisha, Bwk. Type P. Johnstoni, Bwk. 4. Caminus, Sdt. Type C. Vidcani, Sdt. 5. PlACOSPONGiA, Gray. Type P. melobesioides, Gray. The sponges belonging to the group Geodina have been known to naturalists for nearly two centuries, though for the greater part of this time they were lost in that chaotic assem-blage which formed the genus Alcyonium. It was in 1815 that Lamarck* defined, under the name of Geodia, the first genus of the Geodine group ; but so powerful a hold had the imaginary Alcyonian character of these sponges upon the minds of the zoologists of those days, that even after the generic distinctness of Geodia was perceived it was still retained, * Mem. du Mus. d'Hist. Nat. i. p. 333, 1815.
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