42 Transactions of the Royal Microscopical Society. 
branches are usually quite cylindrical, though occasionally flattened 
at their tips; the general appearance being much like that of 
S. sanguineus, but it has a bluer rose tint, and is at once dis- 
tinguished by the minute size of its calicles of an inch) 
which are usually uniformly and densely scattered over the 
branches, a few of which only show them to be more abundant at 
the contiguous edges. Each apparent calicle really consists, as has 
been pointed out in the papers already alluded to, of a central cup- 
shaped calyx (which in life bears the alimentary zooid), having an 
opening in its floor from which a large tube passes towards the 
interior of the corallum : running throughout the whole length of 
the tube is a minutely spined style-like columella whose point 
may be seen in the centre of the hole at the bottom of the calyx. 
Around the calyx and attached to its outer surface is a series 
of from ten to fourteen vertical plates, which, although they so 
closely resemble the septa of an Actinozoan corallum, are really 
only the remains of the coenenchyma which separates the individual 
members of a circle of tentacular zooids that surrounds the central 
alimentary one. The outer border of these plates is attached to the 
surrounding coenenchyma, which is often raised around them so as 
to resemble the theca of an ordinary coral. The edge of this false 
theca is sometimes more raised on the proximal side (nearest fixed 
end of corallum), at other times on opposite sides corresponding 
with the plane of the branches, but is absent or slightly developed 
on the larger branches where the axis of the group of zooids is at a 
right angle to the surface. At some depth between each of the 
septa may be seen a small, rounded, brightly glittering, and nearly 
colourless sphmrule attached to the theca ; much smaller, but 
otherwise similar ones, stud the larger canals, and are especially 
evident around the opening through which the style projects. The 
general substance of the coenenchyma, although exceedingly hard, 
is permeated by numerous small and branched intercommunicating 
canals which open into the main canals of the alimentary and ten- 
tacular zooids, and also upon the general surface, which is somewhat 
raised between them. They appear as white lines on the section 
surface, as their interior appears to be covered with an amorphous 
opaque deposit. 
Besides the calicles which give the chief beauty to the coral, 
some of the branches show small rounded or conical elevations 
(ampullae) of the surface, mostly situated on the non-contiguous 
sides of the branches, the apices of the elevations having one or more 
small perforations. These have been shown by Mr. Moseley to be 
the chambers in which are contained the adelocodonic reproductive 
organs. In some cases the elevation is not marked, although the 
hole is present, which then sometimes has a white spine-like 
process by its side. 
