CORALS FROM THE SILURIAN FORMATION. 279 



Tabulae horizontal, strong, and occupying only the central part of the visceral chambers, 

 where the septo-mural tissue does not extend. Breadth of the calices about half a line. 



Dudley, Benthall Edge ; Lincoln Hill, Coalbrook Dale, Aston Ingham near May Hill, 

 Lmdells, and Woolhope ( Murchison) ; Gothland and Groningue. 



Specimens in the Collections of the Bristol Museum, of the Geological Society, of the 

 Museum of Practical Geology, of Mr. Fletcher, &c. 



2. Thecia Grayana. Tab. LXV, fig. 8. 



Thecia Grayana, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palaeoz. (Arch, du 

 Mas., vol. v), p. 307, 1851. 



Corallum massive, thin, adherent ; basal surface covered with a very thick, circularly 

 wrinkled epitheca. Calices subequal, not prominent, and presenting a rather deep, circular 

 central fossula. 12 septa, equally developed, closely set, very thick, subconfluent exteriorly, 

 and bearing on their upper edge a double row of granulations. Diameter of the calices 

 about half a line. 



Dudley. Collection of Mr. J. Gray. 



This species differs from the preceding one by the lesser number of the septa. 



Family CYATHAXONIDtE, (p. lxv.) 

 Genus Cyathaxonia, (p. lxv.) 



Cyathaxonia? siluriensis. 



Cyathaxonia siluriensis, M'Coy, Ann. and Mag. of Nat. Hist., 2d ser., vol. vi, p. 281, 



1850. 

 _ _ M'Coy, Brit. Palaeoz. Foss., p. 36, pi. i c, fig. 11, 1851. 



" Corallum elongate-conic, about 5 lines long and 2 lines in diameter at the height from 

 the base; strong central axis, nearly one third of the diameter; 60 or 70 strong radiating 

 lamellae, each extending from the axis to the outer wall, before reaching which it bifurcates, 

 leaving a triangular interlamellar space, about equal in width to the distance between the 

 adjoining lamellae ; surface coarsely ridged longitudinally, the sulci corresponding to the 

 divided edges of the lamellae, leaving one of the equal intervening ridges to correspond 

 with each of the spaces between the individual lamellae and between their divided edges. 



"Rare in the upper Ludlow rock of Underbarrow, Kendal, Westmoreland." M'Coy, 

 loc. cit. 



