REPORT ON CORALS—DEEP-SEA MADREPORARIA. 191 
the adult double only towards the margin of the calicle, simple below. Wall finely per- 
forate all over. Calicle in the adult irregularly elliptic in outline, being angular at the 
ends of the long axis, the ratio of the axes being 100 to 200; in the young nearly circular. 
The summits of the smaller axis a little higher than those of the larger axis. Fossa of 
about one-third or one-fourth the depth of the height of the corallum. Columella 
spongy, well-developed, flat at the bottom of the fossa, and not at all prominent in 
it. Septa, in the largest specimen, 112 in number, disposed in the same manner as in 
many species of #/abellwm with numerous septa, the irregularity being produced by the 
development of additional partial systems on either side of the ends of the longer axes 
of the calicle. Septa slightly exsert according to order. Primaries and secondaries 
equal, uniting with the columella deep in the calicle. The outer quaternary septa in each 
half system fuse together over the tertiaries in pairs at their junction with the columella, 
and their junctions are thickened by processes of the spongy columellar substance. These 
outer quaternaries in each half system are far larger than the inner, which latter fuse 
with them at some distance from the columella, and thus bridge over the proximal edges 
of the single pair of quinary septa present in each half system. 
Diagram showing the arrangement of the septa in Balanophyllia bairdiana. 
The septa of successive orders are indicated by numbers. 
The arrangement of the septa in the adult is shown in the accompanying diagram. 
The fusion of the septa resembles that of Deltocyathus and Stephanophylliia. Pourtalés 
remarks on the resemblance of the arrangement in his Balanophyllia florideana to that 
in these two genera." In the younger specimens the fusions of the septa are early 
marked, At first the tertiary septa are seen to be fused at their inner margins over the 
secondaries, but as growth proceeds, these fusions are hidden by the increase of the 
columella and swallowed up in it. 
The smaller adult specimen is much longer and narrower in shape than the one 
figured. It has a more perfectly developed epitheca, a shallower fossa, and in it quinary 
septa are developed only in one or two systems, and in these not in pairs. 
Deep-Sea Corals, p. 42. 
