CORALS FROM THE SILURIAN FORMATION. 289 



very numerous, strong, horizontal towards the centre, and directed upwards towards the 

 circumference. The vesicles that occupy the exterior part of the visceral chamber are large, 

 oblique, and very unequal in size. These corals become sometimes very large ; some 

 specimens are about 7 or 8 inches high. 



Wenlock Edge, Walsall, Benthall Edge, Gleedon's Hill, Dudley. Lincoln Hill, Kin- 

 sham near Aymestry, Ledbury, Malvern, the Valley of Woolhope, and Prolimoor 

 Well (Sir R. Murchison). Mathyrafal, south of Meifod, Montgomeryshire; Craig Head, 

 Ayrshire (M'Coy). 



It is also found in Gothland and in Russia. 



Specimens are in the Collections of the Geological Society of London, of the Museum 

 of Practical Geology, of the Bristol Museum, of the Parisian Museum, of Mr. Bowerbank, 

 M. Bouchard-Chantereaux, M. deVerneuil, M. D'Archiac, and M. Michelin. 



This species, which till of late was confounded with the preceding one, differs from it 

 by its general form, the proportions of the smooth and radiated parts of the calice, the 

 number of septa, and many other characters. 



3. Omphyma Murciiisoni. Tab. LXVII, figs. 3, 3a, 33. 



Cystiphyllum siluriense (pars), Lonsdale, in Murchison, Silur. Syst., p. 691, pi. xvi bis, 



fig. 2 (Ccet. excl.), 1839. 

 Omphyma Murchisoni, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palaeoz. 



(Arch, du Mas., vol. v), p. 402, 1851. 



Corallum turbinate, tall, slightly bent near its basis, and bearing radiciform appendices 

 very high up but in very small number. Accretion ridges of the wall in general strongly 

 characterised. Calice circular, not very deep ; the smooth central part of which is pretty 

 well developed. Septal fossulae very distinct, but not large. Septa (about 60 in number) 

 not closely set, slightly flexuous, and intermingled with some large, very apparent vesicles. 

 A vertical section shows that the tabulae are large, thick, and generally more or less obliquely 

 placed. The vesicles occupying the outer part of the visceral chamber are very large, unequal 

 in size, and very oblique. Height about 2 inches. 



The only specimens that we have seen were found at Wenlock, and belong to the Collection 

 of Mr. Bowerbank. 



This coral much resembles 0. subturbinata} by its general form, but differs from it by 

 the small development of its septa, and the existence of very apparent vesicles on the 

 surface of the calice ; circumstances that induced Mr. Lonsdale to place it in the genus 

 Cystiphyllum. 



1 See tab. lxviii, fig. 1. 



