176 
ACTINIAD^. 
GENERAL DESCRIPTION. 
Form. 
Base. Adherent to rocks ; considerably exceeding the column, outline 
often long-oval. 
Column. Delicately smooth, without much excretion of mucus, wholly 
imperforate, and non-adhesive. Substance fleshy, approaching to pulpy. 
Form hemispheric in button, a low column in flower, much expanded at 
the summit. Margin strongly developed, with a smooth, sharp edge, 
bounding a wide but shallow fosse, within which are seated a single series 
of numerous spherules. 
Dish. Slightly concave, smooth ; the radii faintly marked. 
Tentacles. About two hundred in full-grown individuals, arranged in six 
rows thus ; — 6, ti, 12, 24, 48, 96 = 192 ; moderately slender, shorter than 
the diameter of the disk, sub-equal ; flexuous, usually carried ai'chiug over 
the margin. 
Mouth. Elevated on a blunt cone. 
Colour. 
Base. Edged with a narrow line of bright blue. 
Column. Liver-brown. 
Marginal Spherules. Brilliant azure. 
Disk and Tentacles. Dull pellucid crimson. 
Mouth. Rich crimson. 
Oonidial Tubercles. Blue. 
Size. 
Large specimens sometimes cover with their base an ai’ea four inches 
long by two wide, attain a height of about an inch, and expand to a 
flower of three inches in diameter. 
Locality. 
The Mediterranean and Atlantic shores of Europe, universally distri- 
buted, on exposed rocks, from half-tide, or even a higher level, to low- 
water mark. 
Varieties. 
The characteristic colours of the species are crimson and green. The 
extreme of variation on either hand is produced by either of these two 
colours prevailing so as to exclude the other. But many intermediate 
gmdes are found, either by the blending of the two hues into some inter- 
mediate tint of olive, brown, or liver-colour, or else by the separation of 
the two into a pattern of spots on a different ground, or, where the green 
