CORALS FROM THE CORAL RAG. aS, 
2. Sryzina Denasecait. Tab. XV, figs. 1, la, 14, le. 1d. 
Corallum massive, convex, seldom subgibbose, and sometimes composed of a series of 
thick superposed layers ; common basal plate or wall covered with an epitheca presenting 
concentric folds, and appearing to have been complete originally. Ca/ices not projecting 
much, nor closely set, and placed at very unequal distances from each other. Coste sub- 
granulose, slightly prominent, rather closely set, straight, or slightly curved towards their 
lower end, and alternately larger and smaller; the former corresponding to the sepéa of the 
last cyclum: those of adjoining corallites meet at the bottom of the intercalicular spaces, 
but remain in general distinct. Calices quite circular, but rather unequal in size, especially 
in different specimens ; fossula large, open, and rather shallow. — Co/wmel/a styliform, slightly 
prominent, somewhat compressed, and quite distinct from the sepfa. 'Three complete septal 
cycla, and the elements of a fourth cyclum in two of the six systems. The secondary sep/a 
very little developed in the four small systems, but becoming as large as the primary ones in 
the two other systems, so as to form with these eight principal seyéa, which are somewhat 
exsert, thicker at their ner and outer edge than in the middle, and quite straight. The 
secondary septa are small and delicate ; those of the last cyclum are rudimentary, but are 
represented externally by well-developed mural costa, which are even larger than those 
corresponding to the seyfa of superior orders. A vertical section of the corallum shows 
that the intermural spaces are principally filled up with exothecal tissue and costal lamine, 
but present also some horizontal prolongations of the walls forming ill-defined strata. The 
septa are composed of non-perforated laminze, and the dissepiments, which are horizontal, 
correspond to each other in the different interseptal loculi, so as to divide the visceral 
chamber into a regular series of superposed spaces, somewhat as in the Cyathophyllide. 
The diameter of the calices varies from | to 2 lines, and the breadth of the inter- 
calicular spaces is often double that size. 
‘The specimens which we have examined were found at Steeple-Ashton, and belonged to 
the collections of the Museum of Practical Geology, the Geological Society of London, the 
Bristol Museum, Myr. Philips, Mr. Bowerbank, Mr. Stokes, Mr. Walton, Mr. Sharpe, 
Mr. Pratt, M. de Koninck, and the Paris Museum. 
Stylina Delabechivis easily distinguished from most of the other species belonging to the 
same genus, by the existence of eight apparent systems. The same character is met with 
only in S. ramosa' and in S. Lugdunensis.. The first of these species is of a subdendroid 
form, its calices are unequal, rather distant, and a little more than a line in diameter; the 
total number of the septa is only sixteen. As to S. Lugdunensis, the specimen from which 
the characters were taken is ina very bad state of preservation, and we are not able to add 
1 Pseudocenia ramosa, and P, digitata, D’Orbiguy, Prod., vol. ii, p. 34. 
2 Octocenia Lugdunensis, D’Orbigny, Prod., vol. i, p. 222. 
