0. orasaolamellata -*20< 
marked by co&tal elevations and by granules* Calices crateriform 
As none of the specimens exhibit perfect calices, many of 
these characters have, of necessity, been taken from casts. 
not much elevated above the surface. Wall thin, and rendered in- 
significant by the great development of the septa at the margin* 
Fossa not deep* Costae numerous, and, considering the diameter of 
the septa at the wall , very small; they project but little, and 
are, as a rule, alternately large and small, not dentate, and 
often incline one to the other at their free edge* The larger 
costae present regular enlargements where the cross-tissue 
(dissepiments) of the exotheca joins them: when there are more 
than four cycles of septa, the smaller costae are irregular as 
regards their appearance and development • Columella large, of 
lax laminae, parietal; it doss not project much at the bottom of 
the fossa, and occupies a large space in the corallite* Septa 
numerous, generally characterised by great enlargement at the 
wall, and linear appearance in the rest of their course, the 
higher orders being nearly linear at the wall also. The number 
