CORALS FROM THE MOUNTAIN LIMESTONE. 189 
end of the corallum almost circular. The circle formed by the inner wall, only half the 
size of that formed by the outer wall. Septo-costal radii numerous, about 180, thin, 
almost straight, and unequal in size, alternatively; half of them only pass through the 
inner wall, and extend to the centre of the visceral chamber; the others occupy only the 
external zone. Height of the cora//um about 4 inches; diameter of the exterior wall 
about 13 lines, that of the inner wall being 4 lines. Found at Kildare and in Derbyshire. 
Specimens are in the Collections of the Museum of Bristol, Cambridge, and Paris. 
Professor M‘Coy, in his recently published work on ‘Paleozoic Fossils,’ rejects the 
genus Aulophyllum, that we had previously proposed the existence of; the imner wall being, 
as he remarks, ‘merely a question of degree.” That is very true, but we considered such 
a difference in the degree of development of the constituent part of the corallum as bemg 
of sufficient value to authorise generic distinction, because we do not find any gradual 
passage between the organic form belonging to Cyathophyllum, in which the inner wall is 
rudimentary, or does not exist at all, and that peculiar to Aulophyllum, where the inner 
wall is greatly developed, and almost central. As to the genus Cliscophyllum, to which 
Professor M‘Coy refers the above-described corals, it differs from our genus Au/ophyllum, 
not only by the characters here alluded to, but also by the central elevation of the tabulz, 
and the existence of a true swblamellar columella. 
Aulophyllum fungites diflers from A. Bowerbanki* by its septa being more numerous, 
and its immer wall wider in proportion to the diameter of the corallum. 
Professor M‘Coy’ mentions a small variety of this species, found in the carboniferous 
limestone of Lowick, Northumberland ; and at Beith, Ayrshire. 
2. AuLopHYLLUM BowrrBanki. ‘Tab. XXXVIII, fig. 1. 
AULOPHYLLUM BowerBANKI, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palzeoz., 
p. 414, 1851. 
Corallum very elongate, subcylindrical, curved, and presenting laterally a prominent 
line that appears to correspond to a series of rudimentary septal fossule. Diameter of the 
inner wall about half that of the corallum. Septo-costal lamelle about 120 in number, 
unequal in size alternatively; the large ones rather thick. 
The specimen here described was broken at both extremities, but it may easily be seen 
that its height must have been at least 10 inches. It was found in the Carboniferous 
Limestone in Ireland, and belongs to Mr. Bowerbank’s collection. 
1 See tab. xxxviii, fig. 1. 
2 Op. cit., p. 96. 
