204 MR. H. E. HURRELL ON THE POLYZOA IN NORFOLK WATERS. 
Paludicella. 
The last of the fresh-water genera to which I have to call 
attention is Paludicella, a well-known and highly prized form. 
The tentacular crown is circular and somewhat resembles 
that of Fredericella sultana, but is more slender and graceful. 
When viewed in life, the eversion of the crown is a grand 
sight and is of never-ending interest to the observer. This 
particular polyzoon does not form a statoblast as far as has 
been ascertained, but produces at the end of the season 
a winter bud called the hybernaculum ; this is a sealed cell in 
which the embryo of the polyzoon is carefully preserved 
until the temperature is sufficiently high to induce the rupture 
of the cell and the liberation of the animal to the exercise 
of its full functions. 
During the past two or three years it has been rare in this 
district, and when found has generally been intimately inter- 
twined with Fredericella. I have found Paludicella at Catfield 
and at Rockland, but nowhere in such comparatively luxurious 
growths as at Brundall and Surlingham. It has been reported 
to me from Wroxham Broad during September last, and 
I have no doubt is to be met with in other broads. There is 
every reason why Wroxham and Salhouse Broads should 
produce all the known species of the fresh-water Polyzoa, but it 
has not been my good fortune to get as far up to the present. 
Membranipora monostachys (var. fossaria). 
Whilst Rotifera hunting one bleak Sunday morning at 
Yarmouth, I took some weed from a brackish ditch which was 
encrusted with a form that was then new to me, but which 
was afterwards identified with one of the marine forms of 
the Membranipora monostachys var. fossaria, owing to its 
being found in ditches of the kind mentioned. 
The tentacles of this polyzoon are many times larger than 
the body, which is rarely extended from the coenoecium far 
enough to be seen. 
There is a little operculum or lid, and when the animal is 
seen under the microscope the withdrawal of the animal is 
so sudden and the lid pulled down with such rapidity, that 
the on-looker may well fancy he had heard it snap. 
