REPORT ON CORALS—HYDROCORALLIN &. 37 
apposed minute glistening white granules. The margins of the mouths of the dactylopores 
are often slightly raised above the general surface. 
The older pores of the ccenosteum are very deep and, as may be seen in longitudinal 
sections of the branches or stems (¢.0.), commence deep down within the stem near its 
axis, and bend outwards on all sides to the surface of the branch with a nearly uniform 
curve. The ccenostea of all Stylasteridee are traversed in all directions by a system of 
freely anastomosing and branching canals. In the case of Sporadopora, these canals are 
especially abundant and form comparatively close meshworks, hence the whole ccenosteum 
is spongy and excessively porous when seen in section (PI. I. fig. 1). The ccenosteum may, 
with most truth, be said to be built up of a series of hard partition walls, intervening 
between and enclosing a highly complex system of tortuous canals and cavities. The 
meshwork formed by these canals is closer and smaller towards the surface of the 
coenosteum, more open and with wider meshes in the deeper regions. In the deeper 
regions the main canals, as will be seen from the figure, follow more or less the 
curved directions taken by the walls of the pores on their way towards the surface. 
There is no main system of canals in the axis of the stem connecting all the zooid 
cavities. The deep canals become more or less filled up, and the only connection 
between distant zooids is by the more superficial living meshworks. In some places 
irregular cavities of some extent occur amongst the smaller canals, and beneath the 
ampulla (Pl. Il. fig. 1, G). At the very surface, the canal reticulation is very fine 
indeed. 
The pores are cylindrical pits sunk in the spongy mass of the ccenosteum, and their 
walls are perforated all over by the openings of numerous canals. At their bottoms their 
cavities pass off into a few large main canals of the meshwork. The styles of the 
gastropores are very long, and can be traced deep into the axes of the branches of 
ceenosteum, they having become elongated as the growth of the pores and ccenosteum required 
it. In their deeper regions, these slender styles show a surface composed of a few 
dentate ridges (Pl. XX XV. fig. 1, 8) only, whilst in their upper and functionally active 
region they terminate in a long brush-like mass, composed of complicated branchings of 
fine and delicate calcareous spicules. At the base of this brush-like part of the style, a 
very thin calcareous partition or “tabula” (PI. I. fig. 1, T) is sometimes present, stretched 
across the pore cavity at right angles to its axis. Sometimes two or three such tabulee 
are present in a single gastropore, placed at successively deeper intervals. In some 
instances, two tabule occur close together in a pore, one above the other. These 
tabulze are so excessively thin that I considered them at first to be membranous, but | 
have been unable to dissolve them by the use of very strong alkalis, and I am now 
convinced that they are calcareous. They do not seem to occur in all the gastropores, 
and I have not observed them in any instance in the dactylopores. The dactylopores 
vary much in size, as will be seen from the figures. 
