NOTES ON A PECULIAR FORM CF POLYZOA. 9 
muscles, a digitiform glandular sac, fine branching nucleated 
fibres, which may be nervous. 
I have as yet scarcely adverted tothe most remarkable 
feature of Kinetoskias, viz. the peduncle or stem, which 
appears to exist in all the species, though it is not 
shown in Professor Smitt’s figure of his H. wmbella, having 
probably, as I should imagine, become accidentally detached. 
The mode of formation of this part of the zoarlum, which 
is undoubtedly the homologue of the bundle of separate 
radical tubes socommonly met with among the Polyzoa, is 
extremely curious and interesting, and at the same time, in 
some points as yet, more or less obscure ; as, in fact, may be 
said respecting the mode of formation and development of 
the more ordinary form of radical tubes. 
In the more common form they are cylindrical, jointed, 
chitinous tubes, with rather thick walls, and with very 
scanty contents, beyond a few minute granular particles and 
irregular threads, representing, as it would seem, the 
remains of an endosarc, with which, in order that their pro- 
gressive increase in length, and occasionally complicated 
branching, &c., may be effected, we must suppose the tube 
to be furnished. In fact, it is otherwise impossible, without 
assuming the presence of a germinal material to account 
for the fact, that even after the tubes have attained a con- 
siderable length the extremity, or a considerable part of the 
tube, may undergo great changes in form, as is seen in the 
production of hooks and other means of ensuring adhesion 
to foreign bodies; changes showing a most extraordinary 
adaptability to circumstances. Not the least remarkable of 
these adaptations is the division of the extremity of the 
tube into a multitude of very minute tubular filaments, 
each of which may be traced into independent connection 
with some small foreign body. In the deep oceanic forms 
these are most usually dead globzgerina shells, or the skele- 
tons of other foraminifera, so that having no more stable 
foundation than the soft globigerina ooze, which forms so 
extensively the bottom of the ocean, the delicate Polyzoan 
growths which inhabit those profound depths, are able to 
support themselves by the innumerable multitude of solid 
particles to which they are attached by the hair-like 
terminations of the radical fibres. 
And this is well shown in the case of Ainetoskias, in 
which the dilated lower end of the peduncle breaks up 
into a thick and dense tuft of excessively fine filaments, at 
the end of each of which, when the tuft is slightly teased 
out, a globigerina, or other foraminiferous shell, is seen to be 
