THE OPELET. 
161 
Tentacles. About one hundred and eighty, arranged in four rows; of 
which the first, second, and third contain thirty-six each, the fourth 
seventy-two. These numbers are, however, only approximative ; for the 
crowded condition of the tentacles, the irregularity of theii- serial arrange- 
ment, and the ever-vaiying distension of the disk, make it almost impos- 
sible to count, much less accurately to distribute them into rows. They 
are sub-equal in length ; but what difference there is, is a diminution out- 
wards. All are very long ; those of the first row sometimes upwards of 
four inches in length, and more than doubling the diameter of the di.sk : 
they are slender, and taper uniformly to the tip, which is obtuse and as if 
ti'uncate, or sometimes slightly enlarged ; very lax and flexuous, they are 
almost alwaj's thrown about in irregulai’, snaky curves, intertwisting in all 
directions. Their entire surface is very adhesive. 
Mouth. Seated- on an elevation, which more commonly takes a cylin- 
drical than a conical form ; sometimes large and tumid, at others small : 
lip rounded. 
Colour. 
Column. Pale wood-brown, umber-brown, purplish-brown, or flesh- 
colour, marked with numerous narrow bands alternately paler and deeper, 
which correspond to the furrows ; sometimes the lighter bands are dull 
light lilac, with darker edges. 
Dish. Dark bistre-brown, or umber-brown; the gonidial radii often a 
lighter shade of the same colour. 
Tentacles. Light pea-green or emerald-green, opaque, with a rich, 
satiny lustre ; the extreme tips, for about one-fourth of an inch, rich 
lilac-crimson ; the green gradually blending into the lilac, and the latter 
hue increasing in brilliancy to the extremity. A faint whitish line usually 
runs along the back of each tentacle throughout its length. 
Mouth. Lip agreeing with the disk ; throat ash-brown. 
Size. 
Large specimens are sometimes seen covering an area of six inches in 
diameter, with their tentacles four inches long ; the disk two inches, and 
the column the same, in diameter. 
Locality. 
The western and southern coasts of Europe generally. Shallow pools 
between tide-marks, and littoral rocks. 
Varieties. 
a. Smaragdina. The state described above, with rosy-tipped green 
tentacles. 
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