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ZOOPHYTA.] UPPER PALiEOZOIC RAD I AT A. 107 Genus. STYLASTR/EA (.Lonsd.) Ref.—Geol. Russ. p. 619. Gen. Char.—Corallum forming large masses, composed of prismatic, easily separable tubes, each having a thick, distinct, epithecal wall, marked with vertical costal striae, and transverse rugosities of growth; within the external epithecal boundary of each tube, is a narrow vesicular perithecal zone, usually radiated obscurely by delicate costal prolongations of the radiating lamellae; within the perithecal zone, is a circular lamelliferous area, or true cell, traversed horizontally by distinct, strong diaphragms, without central axis; radiating lamelkc numerous, strong, biplated, of two sizes, not reaching the centre; young, produced as four-sided columns, by a rectilinear boundary, parallel to one of the faces of the old prismatic tube. STYLASTRiEA basaltiformis (Phill. Sp.) Ref. and Syn.—CyathophylVum basaltiformis Phil. Geol. York. Vol. II. t. 2. f. 21. Sp. Ch.—Corallum forming large masses of easily separable prismatic tubes, often ten inches long, usually hexagonal, with an average diameter of four lines, or rather less; circular inner area usually three lines in diameter, radiated by about twenty-five thick primary lamellaj, leaving a clear unradiated central space, of rather more than a line in diameter; narrow outer vesicular area, of from two to four rows of cells, faintly radiated by delicate costal extensions of the thick primary lamellae, and an equal number of intervening secondary lamelkc, which barely enter the lamelliferous zone; surface marked with strong, irregular, transverse wrinkles of growth, and coarse vertical lamellar striae, averaging six or seven in two lines: vertical section, inner area traversed by broad, distinct, nearly flat, subregular, horizontal diaphragms, about five in two lines; outer area, of very highly inclined, slightly curved vesicular plates, usually two in a row. I have seen, in one or two cases, a slight axis-like projection of the middle of a diaphragm, but there was nothing of the sort on the diaphragm above or below it. The peculiar mode of forming easily separable young square tubes is often observed in this species. Position and Locality.—Abundant in the carboniferous limestone of Kendal, Westmoreland. Genus. SIPHONODENDRON (.M'Coy). Ref—M c Coy, Ann. Nat. Hist. 2nd Series, Vol. III. p. 127. Gen. Char.—Corallum of variously aggregated, branching, cylindrical or elongate-conic stems; young branches produced by lateral buds; outer wall thin, lined by two or three rows of small vesicular plates, forming a narrow outer vesicular, or perithecal area in both sections, defined by a thin tubular wall; terminal cups deep, lined by numerous vertical lamellae, alternately larger and smaller, and having in the bottom a small prominent, styliform, compressed axis: vertical section shews a slender, central axis, and a series of large conical or dome-shaped transverse diaphragms, occupying the greater part of the width of the tube, the convexity upwards forming in this section lines diverging downwards and outwards from the axis, till they reach the narrow external cellulose layer on each side: horizontal section shews the small axis, surrounded usually by a few thin concentric lines, which are the edges of the conoidal diaphragms cut through by the section; from these the vertical lamellaj radiated to the circumference, where they are connected by the small transverse vesicular plates, forming the narrow external cellular zone. I have proposed this genus for a number of corals exceedingly abundant in the mountain limestone, but hitherto classed, by Prof. Phillips, Mr Lonsdale, and others, with Lithodendron. This latter genus was originally proposed by Schweigger (Beobachtungen, &c. tab. 6) to include, first, the Oculina of Lamark, including the type of Blainville’s Dendropliyllia; and secondly, a division, which, allowing the previously constituted genus Oculina and the subsequently defined Dendropliyllia to stand for the first division, becomes the real type of his genus, and the four references he gives to Esper’s ‘ Pflanzenthiere’ (L. capitatum fastigiatum, angulosim, cristatum), as examples of this genus are typical examples of the group subse- p 2
