55 
cilia which clothe it entire surface. It is of an elongated conical 
figure, but very contractile. When fully extended, its surface is 
smooth ; but when contracted, it is thrown into transverse rugse, 
which give it a close resemblance to an annuloid animal. The rugae 
never show themselves on the thick extremity, which always con- 
tinues smooth, even in extreme contraction. 
Tubularia coronata. 
In the Tubularia coronata (Y an Ben.) the gonophores are borne 
upon the body of the polype immediately within the posterior circle 
of tentacula. They consist of a long blastostyle carrying numerous 
sporosacs, and are destitute of investing capsule. The zoophyte is 
dioecious. In referring to my notes of this species made some years 
ago, but which I have not since had an opportunity of verifying, I 
find that the phenomena presented by the development of the 
ovum point to a type quite different from what prevails in that of 
the sertularian zoophytes, and in Clava, Coryne, &c. In the present 
species, the embryo is not the result of a transformation of the en- 
tire ovum, as in the instances just mentioned, but is produced from a 
definite portion of the vitellus, the remainder of the vitellus being 
absorbed by the developing embryo. 
The embryo itself is developed on an entirely different plan from 
that of the sertularidans, &c. Instead of presenting the form of an 
elongated ciliated cone, destitute of all appendages, as in the latter, 
it assumes here somewhat that of two short, thick cones placed base 
to base, surrounded at the place of contact by a circle of long filiform 
tentacula slightly thickened at the ends. 
In this condition it leaves the sporosac, and by the aid of its long 
tentacula, moves about freely in the water. 
As development proceeds, and apparently before it had left the 
gonophore, a mouth is found upon one apex of the double cone, and 
round this mouth, a circle of short tentacula afterwards sprout out. 
In a further stage, we find that the opposite apex has become elon- 
gated into a hollow peduncle, by which the young Tubularia per- 
manently fixes itself to some solid body, while the clavate condition of 
the extremities of the tentacula entirely disappear, and these organs 
acquire a uniform thickness throughout. 
Little more is now needed to bring it into the form of the adult 
Tubularia. 
