520 Generat Notes. [May, 
of limpets are invariably free from algz. As might have been an- 
ticipated, Patella is the cause of this freedom. At low tide any 
one on the foakout can hear a quick, regular rasping sound in all 
directions, 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 scrapes 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 suita- 
ble patches whereon to graze. When such a one is discovered, it is 
gradually licked quite clean. Ifthe patch happens to be the sur- 
face of a moderate-sized barnacle, the circular lip is completely 
spread over it, almost tempting one to believe that the crusta- 
cean is about to be “ sawn out.” Such, however, is not the case, 
“house-cleaning” being the sole end in view. Indeed, limpets 
are often serviceable to one another by thus clearing away escu- 
lents growing upon their shells. To secure a dinner, a good deal 
of licking is requisite, and perhaps this habit may help to account 
for the inordinate length ofA ie tongue-ribbon. Certainly, it must 
used up at a very great 
But this is not the only, So aoa I believe the chief way in which 
the limpet feeds. ose individuals which live near large sea- 
weeds, such as Fucus, feed extensively upon them, as their 
gnawed condition testifies. I can speak confidently in this mat- 
ter, having caught more than one limpet in the act. The opera- 
tion was as follows: The edge of a thick flat part of the thallus 
was seized by the lip (as a traveler might commence on a colossal 
sandwhich), and being, I suppose, held firmly by the upper jaw, a 
semicircular “ bite” was gradually excavated by successive scrapes 
of the radula, the edges of the bite being beveled on the under 
side. So far as my observations extended, limpets do not feed 
when covered by water, but always settle down firmly before the 
rising tide reaches them. The intervals between which any par- 
ticular limpet feeds seem to be very irregular; but, as a rule, the 
largest limpets are apparently least fond of long fasts. 
In regard to the second point, the locality-sense, great doubt 
seems to exist in the minds of naturalists as to whether limpets 
go back to the same place to roost. I believe the question was 
answered in the affirmative long since by a Mr. King, but, as far 
as is known to me, he did not publish any details of his observa- 
tions, and this is my excuse for giving an outline of mine. Fol- 
lowing a neces of Mr. yya I marked a porosa of lim- 
