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30 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
FAUNISTIC WORK AT HILBRE. 
As usual members of the Committee and others have 
tried to go to Hilbre Island at the very low tides as often 
as possible during the year. On a visit in April Mr. 
Christophers, a student of the Biological department of 
the College, found a species of sponge (Raspailia sp.) 
which is at least new to the district. We also on that 
occasion obtained various Nudibranchs, some of them 
spawning. The starfishes were very abundant on the 
rocks, and seem to be yearly increasing in number. 
Young mussels were also at this time very plentiful all 
over the rocks. Later in the year we found that the 
mussels had entirely disappeared. To some extent no 
doubt they are eaten by the starfishes and other animals, 
but we have reason to believe that their disappearance as 
they get large is chiefly due to the fact that on account of 
the layer of fine mud which covers all the rocks at Hilbre 
they are unable to attach themselves firmly to any solid 
support and merely cling together by the interlacing of 
their byssus fibres, so that when they come to be of appre- 
ciable size and offer resistance to the sweep of the waves, 
they are readily detached from the surface of the rock in 
large sheets a yard or two in length. We have seen this 
process going on on more than one occasion—the sheets 
of half-grown mussels being rolled up by the waves, and 
then washed about the sands. 
On November 14th some of us went to Hilbre Island 
with Professor Howes (S. Kensington), Mr. Garstang and 
Mr. Bles (Owens College) and some others, when we 
found 8 species of Nudibranchs, Garveia nutans, a Siphon- 
ostomum, the Nemertean Aap Rie us lactifloreus, and 
other interesting forms. 
The amount of Zoophytes and Polyzoa found cast up 
by the recent gales was most astonishing. A few hand- 
