FROM THE ZONE OF AMMONITES ANGULATUS. 15 



The height of the corallum may reach 6 inches. 



Diameter of a coralHte |rd inch. 



Localities. Brocastle, Cowbridge, Laleston, the Sutton Stone, and Ewenny. In the 

 Collection of Charles Moore, Esq., F.G.S., Bath. 



MM. Terquem et Piette ('Le Lias Inferieur de Test de la France,' p. 127, PI. xvii, 

 figs. 1, 8) have described this well-marked species in their usually concise manner. The 

 smaller size of the corallites, the septal number, and the small amount of endotheca, dis- 

 tinguish the species, which is very common in the Glamorganshire beds. The bush shape 

 of the corallam may be imagined from the grouping* of the casts of the species in the 

 limestone at Cowbridge ; and the dichotomous and slender form of the corallum is 

 common at Laleston and in the Sutton Stone. 



The rounded swellings and intermediate constrictions of the plain epitheca are very 

 characteristic. 



The French specimens are derived from the beds at Aiglemont, in the zone of 

 Ammonites angulatas. 



8. Thecosmilia irregularis, Duncan. PI. Ill, figs. 1 — 6 ; and PL X, fig. 5. 



The corallum is small, short, and has a broad base. It consists of a short and rather 

 cylindrical peduncle with a broad base, a very strongly marked and ridged epitheca, and 

 of an upper part whence the calicos spring by fissiparity. 



The calicular surface is considerably broader than the peduncle, and overhangs. 



The calicos are small, shallow, irregular in shape, and have a distinct margin. 



The septa are few in number, large, unequal, and very irregular in their arrangement. 

 They have large rounded teeth upon their upper margins, and the larger septa occa- 

 sionally unite by their inner margins, which are toothed. 



There are about twenty septa, and several others which are rudimentary. 



There are no costse. 



Height of corallum ^ths inch. Diameter of calices -j^ths inch. 



Locality. Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 



Thecosmilia irregularis, Duncan. (A variety.) PI. Ill, figs. 14, 15. 



The calices are deeper, the septa longer and more slender, and the dentations sharper 

 and more distinct than in the type. 



Locality, Brocastle. In the Collection of Charles Moore, Esq., F.G.S., Bath. 



