HABITS OF THE LIMPET. 97 
We have now come to the end of the bivalves: let us pause 
for a while. In the above list I have given only a few of the 
localities known to me for the various species, but have tried to 
select representative ones. Perhaps I have introduced too many 
localities not belonging to the district in question, but I have 
done it in the hope of making the list more generally useful. 
I have touched but lightly on the fossils, because I know but 
little about them; but I wish some one more experienced than 
myself would write a list of the fossil shells of the various 
formations which appear in the district. I will now return to 
the list. 
[Prrropopa.—Hyalea tridentata, one at Hastings (E. Langdon). 
SOLENOCONCHIA. 
Dentalium tarentinum. —Shellness and Margate. [Hastings 
(E. L.).} 
D. nitens.— London clay, D. decussatum and D. ellipticum, 
Gault. 
(To be continued.) 
HABITS OF THE LIMPET.« 
By J. RB. Davis. 
By far the larger number of Limpets (Patella vulgata) “ roost” 
upon rocks whose only covering consists of minute green Alga 
and nullipores, together with numerous acorn barnacles. These 
last are seen to be of very unequal degrees of ‘‘ cleanness,”’ some 
being covered with vegetable growth, others quite white and bare. 
Those immediately surrounding a limpet or group of limpets 
are invariably free from Alge. AS might have been anticipated, 
Patella is the cause of this freedom. At low-tide anyone on the 
look-out can hear a quick, regular, rasping sound in all direc- 
tions, and see numerous limpets slowly crawling about. Scrutiny 
of any particular individual shows that the rasping noise is 
caused by strokes of the radula, which speedily sweeps away the 
incrusting Alge. Whilst ‘‘on the feed” a limpet moves steadily 
on, pretty much in a straight line, and continually sweeps its 
elongated snout from side to side, feeling out probably suitable 
* Krom ‘* Nature.’ 
ZOOLOGIST.—MARCH, 1885. I 
