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34 BRITISH PALEOZOIC FOSSILS. [ZoOPHYTA. Genus. STROMBODES (Schweigger) not of Lonsdale. = Lithostrotion (Lonsd.) ••= Actinocyatlius (D’Orb.) Prod. p. 48. Gen. Char.—Corallum of numerous aggregated, inseparably united, prismatic, polygonal tubes ; triareal; axis thick, prominent, of variously twisted plates ; inner area of vertical radiating lamellae, connected by vesicular transverse plates inclining slightly upwards and outwards; outer area of vesicular plates forming rows of cells extending very obliquely upwards and outwards; thick solid divisional walls between the cells ; young forming circular buds within the parent star, in the outer area. This genus is defined by Schweigger (Beobachtungen awf Naturhistorischen Reisen, $c., tab. 6), as “ Cellulw lamellosce, centro depresso, stirps e conis lamellosis in strata horizontalia conjunctis. Cellula terminalis cyatldformis." And he makes two divisions, first, “ coni e centro proliferifor which he refers to the Amce- nitates Academical of Linne, Yol. I. t. at p. 312. f. 11. and 4. (the former figure, however, shews the origin of a marginal bud at one point). His second group, “cord e disco proliferi” and the reference to the same plate, fig. 10 and 3, refers to a true Cyathopliyllum (C. truncatum, Linn. Sp.); his first group, and the reference to the figures and description in the Amoenitates Academical, must be taken as the types of the genus, and seem fully to justify the reference by Goldfuss of his American Strombodes pentagonum to this genus, the more when the reference in Fougt’s description, above referred to, to fig. 18 of the above plate is taken into account. A coral perfectly similar to that of Groldfuss is also figured by Mr Dana, in Siliman’s American Journal, as an example of Strombodes. As, therefore, the notion that those compound, polygonal-celled corals, are the true Strombodes of Schweigger, seems to prevail extensively, and I think justly, it only remains for me to add, that having carefully examined authentic specimens of the S. pentagonum, I find the cone-in-cone appearance of some of the figures, to be produced by a peculiarity of weathering, by which many of the vesicular plates towards the circumference of the stars have fallen out, and that the coral truly possesses all the characters so admirably elucidated by Mr Lonsdale, in the “ Geology of Russia,” under the title of Lithostrotion—a name which it will be well now to replace by the old title Strombodes of Schweigger. In no case could either the words or reference of Schweigger justify the placing those Silurian and Devonian corals, called Strombodes by Mr Lonsdale, in this genus. Strombodes Wenlockensis (M c Coy). PI. 1. B. fig. 28. Ref.—M c Coy, Ann. Nat. Hist. 2nd Series, Yol. VI. p. 274. Sp. Ch.—Corallum forming large irregular masses of polygonal stems, the mouths of which vary usually from eight to ten lines in diameter; boundary walls strong, prominent, vertically sulcated on the inside; stars depressed round the margin of the walls, forming a large circular convexity nearer the centre, within which is a concavity from which rises the thick prominent compound axis; radiating lamella: twenty-four in small specimens, thirty in large ones, strongest and most prominent on the circular convexity of the star, where an equal number of small alternate ones disappear; vertical section shews the thick central axis composed of irregularly twisted plates; inner area a little narrower than the outer area, from which it is separated by a solid vertical wall, crossed by loose vesicular structure curving upwards and outwards, one or rarely two vesicular plates reaching across the area on each side; vesicular plates of the outer area more curved, slightly smaller, the rows inclining slightly upwards and outwards scarcely three cells in a row. A star nine lines in diameter, has the prominent circular portion seven lines in diameter, and the prominent axis rather more than one line in diameter. To judge from the figure in the Silurian System, that marked t. 16. f. 8 a (not the 8 b ) of Mr Lonsdale’s Acervularia Baltica (Schw.) seems to belong to this species; the species represented by the latter figure has neither axis nor divisional walls to the stars, and is generically distinct. The true A. Baltica of Schweigger, according to his reference to the Amoenitates Academical, has no axis, and cannot belong to this genus, of which the present species is the only one I am acquainted with in Silurian strata. The