48 LIVERPOOL BIOLOGICAL SOCIETY. 
nearest point of Anglesey* (Penmon) by a strait nearly 
a mile wide, through which the tide runs with considerable 
force. There are limestonet cliffs round the greater part 
of the shore, and between tide marks the rocks are 
considerably broken up and worn, so as to form numerous 
shore pools, caves and crevices, in which animals abound. 
The littoral area is rather narrow along the sides of the 
island, but at the two ends it is of considerable extent. 
At the south end especially (see Chart, p. 47) it runs out to 
form a long narrow curved spit, uncovered at low tide, and 
formed by fragments of rock, boulders and gravel. The 
larger stones are piled upon one another in such a way as 
to leave little crevices, nooks, and sheltered pools in which 
the most fragile organisms can live and flourish protected 
from the force of the waves and the scour of the sand. 
This is a rich collecting ground, and many of the rarer 
animals which have been found during this last summer 
on Puffin Island were obtained under the stones on this 
part of the shore. 
The former Dock Board observing station was used from 
1841 to 1863 for the purpose of watching outgoing and 
incoming vessels, and of signalling the news by semaphore 
to the next station on the Great Ormes Head. It consists 
of a one-storied square house (see fig. 5) of four rooms, 
with the chimneys in the centre, large lofts above, and a 
long observatory running out seawards from the northern 
end. ‘There is a narrow flagged yard in front of the door, 
* The nearest neighbours to the Biological Station are the inhabitants of 
the Lighthouse on this corner of Anglesey. The committee desire to express 
here their thanks to Mr, J. Steer, the head keeper, for the friendly interest he 
has taken in their work, and for his kindness in receiving letters and parcels 
for the Island and for helping in various other ways. 
+ For an account of the Geology of the Island, see a paper by Mr. Gregory, 
F,G.S., of the British Museum, further on in the present volume, 
