DvuErpDEN—Wotes on the Hydroida and Polyzoa. 330 
This species was first found and described by Professor G. O. 
Sars from Drobak, in Christiania Bay,’ where it is a rare form. 
It has apparently not been obtained before from British waters. 
It was found growing profusely on two Fusus shells inhabited by 
hermit-crabs, trawled by the Survey from a depth of 220 fathoms 
off Achill Head. 
It is a delicate species, and the polypary is quite colourless in 
spirit specimens. ‘The polypites are very fragile, and capable of 
great extension. The stem is perfectly straight and upright, and 
the branches are given off mostly alternately. The examples 
obtained from the west coast of Ireland agree with Sars’s descrip- 
tion and figures of the Scandinavian specimens, except that the 
branching is not so prolific. This character, however, seems liable 
to considerable variation. On some stems most of the branches will 
be simple, only two or three presenting a bifurcation, and then these 
are near the apex. Other stems have the majority of the branches 
divided. In Sars’s specimens a second bifurcation occurs, produc- 
ing an appearance quite suggestive of the specific name. 
Owing to the fact that the reproductive bodies are not known, 
the exact generic position cannot be determined, but there seems 
little doubt from the form of the hydrothece and the polypites 
that it is a species of Campanulina. 
Many of the pedicels, and often the upper part of the stem, 
have occasional annulations, suggestive of frequent renewal of the 
polypites and extension of the polypary. 
Habitat.—On Fusus shells, from deep water off the west coast 
of Ireland. ‘T'wo shells, each with a large number of stems, were 
trawled by the Royal Dublin Society’s Survey, at a distance of 
40 miles off Achill Head, from the great depth of 220 fathoms. 
POLYZOA. 
The Polyzoa collected by the Survey, although numerous, are 
not of such great interest as the Hydroids. Some of them have 
already been noticed.» The important additional Irish localities 
1 Forhand. Videnskabs-Selskabet. Christiania, 1873, p. 121, pl. v., figs. 9-13. 
2 On Some New and Rare Irish Polyzoa,’’ Proc. Roy. Irish Acad., 3rd Ser., 
vol. iii., pp. 121-136. 
