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112 BRITISH PAL/EOZOIC FOSSILS. [ZoOPHYTA. (Systematic place uncertain.) Genus. HETEROPHYLLIA (.M'Coy). Ref.—M c Coy, Ann. Nat. Hist. 2nd Series, Yol. III. p. 126. Gen. Char.—Stem elongate, subcylindrical, irregularly fluted longitudinally; horizontal section, few distant lamellae, destitute of any order of arrangement, but irregularly branching and coalescing in their passage from the solid external walls towards some indefinite point near the centre, where the few main lamellae irregularly anastomose; vertical section shewing about the middle an irregularly flexuous line (the edge of one or two of the radiating vertical lamellae), from which on each side a row of thin, distant, sigmoidally curved plates extends obliquely upwards and outwards, forming a row of large rhomboidal cells on each side. The paradoxical characters of the lamellae, their perfect want of symmetry of disposition, and their irregular branch-like union among themselves, together with the remarkable openness of the cellular struc ture, render these corals totally unlike any other recent or fossil group. From Cladocora and Caryophyllia, to which they are most allied, they are distinguished by the want of the cellular axis, and by their few, unsymmetrical and anastomosing lamellae. I suspect the Cladocora ? sulcata of Lonsdale may belong to this group, but I have not seen examples of it myself. ITeterophyllia grandis (M c Coy). PI. 3. A. fig. 1. Ref—M c Coy, Ann. Nat. Hist. 2nd Series, Vol. III. p. 126. Sp. Ch.—Stem slightly flexuous, about five lines in diameter, scarcely tapering in three inches, longi tudinally marked with deep unequal grooves, and few, large, polygonal, unequal ridges, giving a very irregularly angulose section to the stem; surface smooth, internal structure as given in the generic character. Position and Locality.—Rare in the carboniferous limestone of Derbyshire. Explanation of Figures.—PI. 3. A. fig. 1. Natural size from Derbyshire, shewing the irregular longi tudinal costse.—Fig. 1 a. Do. Horizontal section magnified three diameters, shewing the irregular anasto mosing of the lamellae. LIeterophyllia ornata (M'Coy). PI. 3. A. fig. 2. Ref.—M c Coy, Ann. Nat. Hist. 2nd Series, Vol. III. p. 127. Sp. Ch Stems subcylindrical, long, flexuous, averaging one and half lines in diameter, with about sixteen narrow, subequal, longitudinal ridges sharply defined, and separated by flat spaces rather wider than the ridges they separate; the ridges are set with small round tubercles more than their own diameter apart; surface very minutely granulose: internal structure as in generic character; horizontal section, lamella: about fourteen at the margin (one usually coinciding with each external ridge). Position and Locality.—Rather rare in the carboniferous limestone of Derbyshire. Explanation of Figures.—PI. 3. A. fig. 2. Natural size from Derbyshire.—Fig. 2 a. Do. Magnified four diameters, shewing at top the horizontal section and irregular anastomosing of the lamellae, below this the external surface with the tuberculated costse; and at bottom the vertical section shewing the dis tant, oblique, interstitial plates, the mesial line being formed by some of their edges.