File:A naturalist's rambles on the Devonshire coast (Page 29) (5981270830).jpg

THE TENTACLES. 20
arranged in about six rows ; the innermost series con-
tains about twelve tentacles ; the next about the same
number ; the third about twice as many ; the fourth
is ag-ain doubled ; the fifth increases in the same pro-
portion, and the sixth contains about thrice as many
as the fifth. This ratio, if accurately carried out,
would give a total of seven hundred and sixty eight
tentacles to one Actinia, a number which is not far
from the mark, though as in other species, the rows
are not quite regular. The inmost series of tentacles
is usually erect, or even inclines inwards, the others
decline more and more towards the circumference,
until the outmost two or three rows lie quite flat upon
the disk, to which the exterior one of all forms an
exquisite fringe ; all the rows are small, but they
diminish outwardly in size, and more rapidly the
nearer they approach the edge ; those of the outmost
row are very minute, the longest (for they are not
equal) not exceeding the sixteenth of an inch in length,
and some being only tiny tubercles : they are slender,
and set so close together, that I counted sixty in
an inch.
The mouth is oblong, sometimes contracted to a
slit, at others showing a sub-oval, or lozenge-shaped
opening, with the lips within finely crenated. Deli-
cate depressed lines diverge from the mouth to the
circumference of the disk, by tracing which we shall
find that the convex space included between two lines
leads to and terminates in a tentacle ; the disk may
in fact be described as formed of the roots of the ten-
tacles soldered together. Viewed from outside, with
a strong light behind, the substance of the disk is