CORALS FROM THE SILURIAN FORMATION. 28] 
TRYPLASMA ARTICULATA, Lonsdale, in Murchison, Vern., and Keys., Russ. and Ural, vol. i, 
pl. a, fig. 8, 1845. (Not Cyathophyllum articulatum, Hisinger.) 
CyarHorHyitLuM? Lovent, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palzeoz. 
(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. Coste 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 costa, 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 paleontologist to 
Cyathophyllum flecuosum of Goldfuss, belongs to this species. 
2. CYATHOPHYLLUM aNGustuM. ‘Tab. LXVI, figs. 4, 4a. 
CyaTHOPHYLLUM aNGuUsTUM, Lonsdale, in Murchison, Silur. Syst., p. 690, pl. xvi, fig. 9, 1839. 
— — D Orbigny, Prodr. de Paléont., vol. 1, p. 47, 1850. 
CysTIPHYLLUM BREVILAMELLATUM, M‘Coy, Ann. and Mag. of Nat. Hist., 2d ser. vol. 6, 
p. 276, 1850. 
— — M‘Coy, Brit. Paleoz. Foss., p. 32, pl.i B, fig. 19, 1851. 
CYATHOPHYLLUM ANGUSTUM, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palzeoz. 
(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 tabule 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 
13 inch. 
