CORALS FROM THE MOUNTAIN LIMESTONE. 193 
9, LitHostRoTion ENsIFER. Tab. XXXVIII, figs. 2, 2q. 
LitHostrotion ENsIFER, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palzoz., 
p- 442, 1851. 
Corallum massive, with a flat or sub-convex surface. Corallites separated only by a 
very thin epithecal wall, which in some places is scarcely visible. Cadices polygonal, often 
ill-circumscribed, almost flat towards their circumference, and presenting, in their centre, 
a shallow fossula. Co/umella stout, compressed, and very prominent. Principal septa 
about 30 in number, thin, nearly straight, somewhat unequal alternately ; some rudimentary 
ones. Diameter of the corallites 4 or 5 lines. 
From Clifton, (Bristol Museum.) In this fossil the columella is more prominent than 
in any other species of the same genus, and the walls much thinner; by the mode of 
coalescence of the corallites it bears some resemblance to the genus Pdz/lipsastrea, in 
which the walls disappear completely. 
3. LirgosTRoTion ARANEA. ‘Tab. XXXIX, figs. 1, la. 
ASTREA HEXAGONA, var. MINOR? Portlock, Rep. on Londonderry, p. 332, pl. xxiii, fig. 2, 
1843. 
ASTREA ARANEA, M‘Coy, Syn. Carb. Foss. of Irel., p. 187, 1844. 
NemaPHYLLUM ARANEA, M‘Coy, Ann. and Mag. of Nat. Hist., 2d series, vol. ili, p. 135, 
1849. 
LasmocyaTHus ARANEA, D’ Orbigny, Prod. de Paleont., vol. i, p. 160, 1850. 
LITHOSTROTION ARANEA, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Paleoz., 
p. 443, 1851. 
Corallum massive. Corallites irregularly polygonal, some of their sides being some- 
times curved, whilst most of them are straight. Inner wall rather distinct. Colwmella 
compressed ; its transverse section fusiform. Sepéal radii very thin, but well developed, 
and slightly flexuous; 22 or 24 principal ones, extending almost to the columella; an 
equal number of smaller ones that do not reach to the inner wall. Great diameter of the 
Calices about 6 lines; that of the inner wall about half. Dissepiments of the exterior 
zone very numerous, and forming small, closely set vesicles. Zubule appearing to be 
numerous, and much raised towards the centre by the Columella. 
Found at Armagh, Ireland; the specimen represented in this Monograph belongs to 
the collection of M. de Verneuil. 
The fossil which Col. Portlock considers as a small variety of the Astrea hewagona 
belongs probably to this species ; it was found in Ireland. 
