REPORT ON CORALS—HYDROCORALLIN 2. 63 
general plane of the flabellum. This tendency is, however, to a large extent obscured 
by irregularities. One face of the flabellum, viz., that rendered convex by the curving 
of the whole mass, is entirely devoid of cyclo-systems ; whilst a considerable number are 
scattered over the surface of the branches on the concave face. As the branches thicken 
by growth of cconenchym, the cylindrical masses of the eyclo-systems become buried, and 
only their free ends remain in view as the mouths of pore systems on the surfaces 
of the branches. Even these mouths become partially overgrown in the active 
regions of the coral, and in the older parts of the stem frequently obliterated. The 
cyclo-systems consist of a deep gastropore, provided with a’ style, and surrounded by 
from twelve to sixteen dactylopores. The dactylopores are provided with a small hirsute 
style, as in Stylaster densicaulis. 
A diagrammatic view of a cyclo-system, as seen from above the mouths of the 
pores, is given in Plate I. fig. 13.. The styles are supposed to be brought into view by 
deep focussing of the lens. The form and arrangement of the pores are almost exactly 
similar to that already described as occurring in Stylaster. 
The very small ampulle are spherical cavities, which are usually entirely sunk 
beneath the surface, but sometimes near enough to it in situation to raise upon it very 
small conical elevations, which easily escape notice, and are present only here and 
there. The ampulle are present in abundance in the walls of the pore systems and at 
their bases. 
Soft structure of Allopora profunda (Pl. VI.). 
Canosarc.—A surface layer of ectoderm covers the surface of the coral, as in Stylaster 
densicaulis, and is reflected into the pores to form the sacs of the zooids. The 
ccenosareal canals form a fine superficial reticulation at the surface of the coral, beneath 
the surface layer, and spring from a deeper meshwork of larger canals which, as in the 
Stylaster already described, have a mainly longitudinal course within the thickness of 
the walls of the pore systems, parallel to the axes of the systems, and lead almost 
directly from the bases of the dactylozooids with which they anastomose to the large 
canal offsets given off at the periphery of the bases of the gastrozooids. At the inner 
surface of the gastropore are finer canals springing from this main meshwork, and from 
these spring a series of offsets which pass in a direction radial to the axis of the gas- 
tropore, to abut on and become united with the outer surface of the sac of the 
gastrozooid, : 
The radial offsets are disposed irregularly, at unequal distances from one another, and 
at all heights in the gastropore (Pl. VI. RR). The inner ends of the radial offsets are 
often enlarged where they abut on the wall of the sac of the gastrozooid, and they are 
often forked at their outer extremities, where they spring from the ccenosarcal meshwork. 
