27 
Ohs. — When the surface of the coralliim becomes at all worn the 
slight obliquity of the calice months is entirely lost, and the septa are then 
visible round the otherwise rather funnel-shaped calices. They vary from 
eight to ten, and the intermediate depressed spaces, or grooves, are even more 
conspicuous than the septa themselves. 
Both in longitudinal and transverse sections, the enormous thickening 
of the walls towards the peripheral portion is very apparent, and in some 
cases the calices become almost obliterated by it, although the primordial 
walls are usually still to be seen, and the original polygonal outline of the 
corallites. This thickening increases towards the periphery of the corallnm. 
The great length of the corallites is also noticeable in vertical sections, and 
the fact that they remain oj^en throughout their whole course, the outward 
curvature from the central or axial portion of the corallnm being a gentle one. 
The corallites are in close contact with one another, but even at an early 
point in their course the same thickening of the walls is visible, although to 
a less extent than towards the peripheral portion. The complete tal)uloe arc 
placed at variable distances apart, sometimes horizontal, at other times 
oblique to the axial line of the corallites they traverse. 
When well preserved the margins of the calices are erect and thick- 
ened ; this, with their deep funnel-shaped interiors and strong septa at once 
recalls the structure of Striatopora, Hall. 
The pores are very irregularly distributed. In some cases they occur 
singly, at other times are clustered together. They are quite round, and, for 
the size of the corallite, large. Some very instructive internal casts of the 
calices of this coral have been found at Boorook, (PI. I, Fig. 8) in which 
not only the grooves left by the imprint of the septal stria3 arc visible, but 
projecting from these casts, either at right angles or at a slightly-inclined 
angle, are a numljer of thorn-like projections, which are the infillings of the 
pores placing the various corallites in communication with one another. The 
whole of the immensely- thickened walls have been removed, but the ornamenta- 
tion of the surface is preserved on the impression of the fossil. The distance 
apart of these “thorns” excellently demonstrated the thickness attained by 
the secondary deposit. It is quite clear that not only the peripheral portions 
were thickened, but the central vertical portions of the tubes likewise, whilst 
tlie proper wall is very apparent. There can be no possibility of doubt that 
the septal ridges extended for some distance into the calicular orifices, as 
shown by the grooves on their internal casts. 
