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42 BRITISH PALAEOZOIC FOSSILS. [ZoOPHYTA. Position and Locality Common in the schists of Pen Lar, Llandovery; Mathyrafal, S. of Meifod, Montgomeryshire; Llansantfraid, Glyn Ceiriog, Denbighshire; and Castel Craig, Gwyddon, Llandovery, Caer- marthenshire; fine Caradoc sandstone of Alt yr Anker, Meifod, Montgomeryshire. Explanation of Figures.—Plate 1. B. fig. 25. Natural size of cast from the slates of Llansantfraid. Fig. 25 a. Do. Two of the interlamellar projections of the cast, magnified three diameters, each with a small row of puncta corresponding to the secondary lamellae, and divided by the deep slit corresponding to one of the primary lamella'. [Systematic place uncertain.] Genus. SPONGARIUM (M.Edm.) 1839. = Discophyllum (Hall, 1847) = Actinophyllum (Pliill. 1848). Gen. Char.—Corallum simple, thin, corneous, broad oval, depressed, saucer-shaped, attached by a small oval central space to foreign bodies; inner concave surface smooth, exterior surface with numerous simple, or once or twice branched, ridges radiating from the centre to the circumference; both surfaces strongly marked with irregular concentric wrinkles and striae. The affinities of these fossils are very obscure, the first example being referred to the &'pongidee by M. Edwards, the second to corals by Hall, and to plants (Calciphytes) by Profs. Phillips and Forbes, and Dr Hooker. (See Mem. Geol. Survey, Vol. II. p. 386). All observers agree that there is little or no cal careous matter in them, which makes the latter opinion doubtful; the first impression on my mind was that they might be a sort of corneous base of a polype allied to Actinia—but I have observed that the inner, upper, or concave side is unradiated, which is a fatal objection to that notion ; as to its being allied to the cartilage of Velella or the like, that is also impossible, as I have noticed a specimen firmly attached by the grasping of its base round a bit of Orthoceratite. From the examination I have made I do not think it possible to separate, generically, the species with simple rays (Discophyllum and Actinophyllum) from those in which they are branched (Spongariurn)—the character affording scarcely a recognizable specific distinction in practice. Spongarium aequistriatum (.M'Coy). PI. 1. B. fig. 15. Ref.—M c Coy, Ann. Nat. Hist. 2nd Series, Vol. VI. p. 281. Sp. Ch.—Elliptical, depressed, proportion of width to length varying from as 85 or 90, to 100; marked with sharp, rugged concentric wrinkles, entire disk closely and equally radiated, by coarse rounded very approximate ridges, averaging five in one line; long diameter from eight lines to one inch. This species is perfectly distinguished from its congeners by the coarse, close, equal, striation of the entire disk, giving it a peculiarly harsh aspect; the ridges are much less than their thickness apart. Position and Locality.—Rather rare in the quartzose Upper Ludlow rock of Benson Knot, Kendal, W estmoreland. Explanation of Figures.—PI. 1. B. fig. 15. Natural size from the Upper Ludlow rock of Kendal.— Fig. 15 a. Do. Portion of outer surface magnified two diameters, shewing the rugged, subequal, striae. Spongarium Edwardsi (Murch.) -Be/l—Murchison, Sil. Syst. t. 26. f. 12. Sp. Ch.—Nearly orbicular, very broad oval, proportion of breadth to length, as 90 to 100 ; radiating ridges comparatively few, slender, thread-like, some distinctly branching two or three times (when the diameter is one inch), a few others remaining simple, averaging one line to nearly two lines apart, inter vening spaces flat marked with few irregular obtuse concentric wrinkles, without distinct intervening radiating striae ; average diameter one inch.