CORALS FROM THE SILURIAN FORMATION. 28 J 



Tbtplasma articulata, Lonsdale, in Murchison, Vern., and Keys., Russ. and Ural, vol. i, 



pi. a, fig. 8, 1845. (Not Cyathophyllum articulatum, Hisinger.) 

 Cyathophyllum ? Loveni, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Paleeoz. 



(Arch, du Mus., vol. v), p. 364, 1851. 



Corallum simple, or accidentally aggregate, very tall, nearly cylindrical, subpedicillated, 

 and slightly curved near its basis. The differences in the degree of activity in the 

 development of the polyp are so very great, that the corallum presents an alternate series of 

 circular constrictions and prominent ridges, and has somewhat the appearance of a pile of 

 cyathiform corallites. Costge rather thick, equally developed and flat. Calice circular, 

 rather shallow. Septa about 60 in number, alternately large and small, closely set, and 

 bearing numerous strong marginal denticulations. The small septa correspond to the 

 middle of the costae, and the large ones to the intercostal furrows. Height about 12 

 or 15 lines; breadth of the calice 4 or 5 lines; depth about 2 lines. 



Found at Wren's Nest near Dudley ; and in Gothland. 



Specimens in the Collections of M. de Verneuil and M. Bouchard-Chantereaux. 



This species is easily recognised by its prominent circular accretion ridge, which gives 

 to it a lamellated appearance, much resembling that of Chonophyllum ; it differs, 

 however, from this genus by the great development of the septal apparatus. 



We are inclined to think that the fossil coral found by Professor M'Coy at Egool and 

 Bellaghaderreen, in the county of Mayo, and referred by that palaeontologist to 

 Cyathophyllum flemosum of Goldfuss, belongs to this species. 



2. Cyathophyllum angustum. Tab. LXVI, figs. 4, 4a. 



Cyathophyllum angustum, Lonsdale, in Murchison, Silur. Syst., p. 690, pi. xvi, fig. 9, 1839. 



— — IfOrbigny, Prodr. de Pale'ont., vol. i, p. 47, 1850. 

 Cystiphyllum brevilamellatum, M'Coy, Ann. and Mag. of Nat. Hist., 2d ser. vol. 6, 



p. 276, 1850. 



— — M'Coy, Brit. Palaeoz. Foss., p. 32, pi. i B, fig. 19, 1851. 

 Cyathophyllum angustum, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palseoz. 



(Arch, du Mus., vol. v), p. 365, 1851. 



Corallum simple, straight, tall, somewhat compressed (may be accidentally), and 

 presenting but few feebly developed accretion ridges ; septa very thin, placed about half a 

 line apart, and united by strong dissepiments, so that when the epitheca is worn away (as 

 in the specimen here figured) the surface of the corallum appears covered with regular 

 square cells. A vertical section shows that the tabulae are small, closely set, somewhat 

 irregular, and occupy only one fourth or one fifth of the diameter of the corallum ; the rest 

 being filled up with vesicular cells that are placed obliquely, and are about half a line 

 broad. The height of the corallum was probably about four inches ; diameter about 

 1 J inch. 



