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 corallum 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 'Palaeozoic Fossils/ rejects the 

 genus Aulophyllum, that we had previously proposed the existence of; the inner 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 being 

 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 Clisiop/iyllum, to which 

 Professor M'Coy refers the above-described corals, it differs from our genus Aulophyllum, 

 not only by the characters here alluded to, but also by the central elevation of the tabulae, 

 and the existence of a true sublamellar columella. 



Aulophyllum fungites differs from A. Bowerbanki l by its septa being more numerous, 

 and its inner wall wider in proportion to the diameter of the corallum. 



Professor M'Coy 2 mentions a small variety of this species, found in the carboniferous 

 limestone of Lowick, Northumberland ; and at Beith, Ayrshire. 



2. Aulophyllum Bowerbanki. Tab. XXXVIII, fig. 1. 



Aulophyllum Bowerbanki, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palaeoz., 



p. 414, 1851. 



Corallum very elongate, subcylindrical, curved, and presenting laterally a prominent 

 line that appears to correspond to a series of rudimentary septal fossulae. Diameter of the 

 inner wall about half that of the corallum. Septo-costal lamellce 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. 



