WRIGHT—ON TUBIPORA MUSICA. 215 
IT regret very much that I had no opportunity of watching the deve. 
lopment of the egg of Tubipora, or even of seeing the formation by 
budding of the attached zooid forms. From an examination, however, 
of a large series of specimens, it 1s, I think, pretty evident that the 
external tabule are formed in the first instance as flattened offshoots 
from the upper edges of the tubes. Thus in many instances flat plates 
will be found to project from the upper and still soft portion of the 
tube; each plate will consist of a fold of ectoderm, into which some of 
the endodermic layer is tucked ; spicules are freely secreted in the outer 
layer of this fold, which is of a bright-red colour; and in one or two 
instances a small swelling was seen to arise from the free end of this 
lateral fold-like prolongation of the tube. I have little doubt that these 
swellings were the starting points of fresh polyps. It must not be 
forgotten that, while in some masses of Tubipora the skeleton tubes 
were all close together, and the polyps all on the same level, in many 
others the masses were very much less compact, and the polyps were 
growing in an irregular manner. 
The polyp certainly can, and does, constantly add to the height of 
its tube; or, in other words, the spicules are being constantly consoli- 
dated into the tube, and the tube thus increases in height. In some 
cases I have been able to trace the mesenteric bands, which attach the 
lower portion of the body ofthe polyp to the walls of the skeleton tube, 
as far as the second external septum in depth; and it is very evident 
that, as the outer walls of the tube become consolidated, not only does 
the tube become elongated, but the polyp elevates itself at the same 
time in the tube. 
I am inclined, with Milne-Edwards, to regard the genus Tubipora 
as belonging to the first family of the order Alcyonaria, viz. Aleyonide, 
but would place it as a separate section of the sub-family Alcyonine. 
Thus we should have— 
Order ALCYONARIA. 
Family 1. Atcyon1p@. 
Subfamily 1. Cornularine. 
5A 2. Aleyonine ; and, dividing this into three sec- 
tions, as follows :— 
Aleyonine. 
(1.) Naked or soft, as Aleyonium. 
(iz.) Armed with large spicules, as Nepthya. 
(a1r.) Tubed; tubes formed of coalesced spicules, as in 
Tubipora. 
Some may perhaps consider it advisable to give more weight to the 
great difference in the calcareous secretions, and place the genus in a 
subfamily to rank as athird subfamily of the Alcyonide, called Tubipo- 
rine, which would be characterized by having lenticular spicules de- 
veloped in the tentacles, the fusiform spicules of the outer body layer 
forming dense hard tubes, united to each other by calcareous septa. 
