430 MR, H. N. MOSELEY ON THE STRUCTURE OF THE STYLASTERXDiE. 
the smaller. They are deep, reaching nearly to tire centra laxis of the branch or stem 
on which they are situate, and contain a deep-seated, long, and slender style. The 
smaller more numerous pores, the dactylopores, are thickly dispersed between the 
larger ones. They have no style. The pores are usually more abundant on one face 
of the coral flabellum than on the other ; indeed, large areas of what may be called 
the back of the stem are often devoid of pores altogether. 
The appearance of the surface of the corallum as seen by reflected light under a low 
magnifying power is shown in Plate 35, fig. 2. The surface presents slight irregular 
undulations. Its texture is somewhat like that of loaf sugar, being composed of 
closely 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 corallum are very deep, and as may be seen in longitudinal 
sections of the branches or stems ( t.o .), 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 coralla of all Stylasteridse 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 corallum is spongy and excessively porous when seen in section (Plate 35, 
fig. 1). The corallum 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 corallum, 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 connexion between distant zooids is by the more superficial living 
meshworks. In some places irregular cavities of some extent occur amongst the 
smaller canals, as beneath the ampulla (Plate 35, 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 corallum, 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 
corallum, they having become elongated as the growth of the pores and corallum 
required it. In their deeper regions, these slender styles show a surface composed of 
a few dentate ridges (Plate 35, fig. 1 , S) 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 ” (Plate 35, fig. 1 , T) is some- 
times present, stretched across the pore cavity at right angles to its axis. Sometimes 
