126 
MR, H. N. MOSELEY ON THE 
The outer epithelial layer is not seen, being too transparent. The super- 
ficial projecting points of the hard tissue of the corallum are opaque, and are 
shown shaded dark. Away from the calicle the points are arranged in 
parallel rows. All over the surface are seen the tops of the ramifications of 
the superficial system of canals or sinus (V, V, fig. 1) ; those immediately 
around the polyp-lobes have a radiate arrangement. These canal-cavities are 
lined with entodermic cells. 
In the centre of the drawing are seen the eight lobes of the contracted 
polyp with the mouth of the atrium in their centre. In their peripheral 
region the entodermic lining of the cavities of these lobes is seen showing 
through their superficial tissue. 
Each of the lobes further shows a fine longitudinal striation, probably 
caused by muscular fibres, and very small nuclei at its inner aspect. 
P. Projecting points of the corallum. 
AA. Sinus of the superficial canal-system. 
L. Lobes of contracted polyp. 
Fig. 6. Portion of a section of Heliojpora ccerulea parallel to the surface and viewed 
from beneath. Prom a specimen decalcified in chromic acid. The drawing 
represents a spot where a growing point of the corallum has been removed by 
the acid. 
EN. Entodermic layer. 
C. Homogeneous connective-tissue layer. 
D. Layer of connective-tissue cells. 
B. Very finely fibrous mass from which the calcareous tissue has been 
removed. 
A. Cavity in the mass. 
PLATE 9. 
Fig. 7. Diagram to show the canal-systems in connexion with the summits of the 
ccenenchymal tubes and calicles. 
A. Cavity of a calicle. 
B. Cavity of a tube. 
D. Walls of these in longitudinal section. 
The canals of the deep system (V, V') lead over the summits of the walls 
from one tube to another, and from the tubes to the calicular cavities. The 
canal (V') opening into the calicular cavity in the figure corresponds to the 
opening (O) in fig. 8. 
C. A similar canal leading into a tube behind B. 
Above is seen the superficial canal-system, consisting of smaller canals and 
sinus communicating with the deep canals and roofs of the ccenenchymal 
