Pvn H,i I'UitlS

34 ANOMIID^. '
tally detached from oysters in an adjoining bed,
to which
they were originally affixed, and being thus deprived of
their plugs, as w T
ell as of the power to make new ones,
they filled up the openings writh
a shelly substitute, for
the sake of protection against starfishes and other ene-
mies. Having lost their own plugs, they were well
satisfied by being securely moored to the bed by the
strong cables of their friendly neighbours,
the mussels.
I dredged a specimen of the variety " squamula" off
Croulin Island, Skye, which was free, but had the orifice
completely closed in the same way
as the Welsh exam-
ples. The A. tubularis of Turton is a young specimen
of the same variety, in which the orifice had only been
partially closed. Old Martin Lister wr as well acquainted
with the typical form, and gave an excellent figure of
it in his '
Historia Conchvliorum.'
2. A. patellifor mis *, Linne.
A. patelliformis, Linn. Syst. Nat. p. 1151 ; F. &IL ii. p. 334, pi. lvi. f. 5,6.
Body resembling that of A. ephippium, but the colour is
deeper : mantle thinner : cirri of unequal length and size, and
capable of considerable extension, some of them being a quarter
of an inch long ; they are minutely and closely ringed, and a
dusky line runs down the middle of each. No other part of
the animal is visible outside.
Shell round or sometimes longitudinally oval, usually flat-
tened, thin, rather glossy towards the beak, but elsewhere of
a dull : appearance sculpture, fine and close-set imbricated
scales, and 20-30 blunt ribs which radiate from the beak in
lines
every direction towards the margins in a wavy manner ;
of : growth irregular colour yellowish-white, with frequently
reddish-brown but not continuous streaks or : spots margins
behind :
thin, scalloped or notched by the ribs, nearly straight
bealc
hind
small, rather prominent, very seldom reaching to
margin, and never overlapping it :
cartilage short
the
and
* Shaped like a Patella, or limpet.