COLOUR VARIATIONS IN ACTINIAE. 231 



bottom of a rock pool at East Pen tire, Newquay, Cornwall. This pool 

 was full of a growth of dark Algae, with which colonies of red species 

 showed as thin, irregular, red streaks and lines. The *S". miniata was 

 very large, and its outline most irregular ; the scarlet-cored outer row 

 of tentacles so exactly resembled the red Algae, and the rest of the 

 animal the dark Algae, as to render it most difficult of detection. I 

 watched for some time and observed an amphipod deliberately swim 

 into the scarlet tentacles, doubtless deceived by their resemblance to 

 the Algae. 



Cereus pedunculatus (Sagartia bellis). I had long considered that 

 many of the numerous varieties were to be interpreted as aggressive, 

 but a careful study of pools at New^quay, etc., brought out additional 

 and interesting cases of adaptations. 



In pools similar to that described above, a variety of a dusky umber 

 hue was abundant, with frequently streaks and shades of red upon the 

 inner tentacles and disk. This type predominated in those pools 

 where the Algae were dark, with red species intermingled. When 

 fully expanded the anemones resembled the dark weeds ; when alarmed 

 and partially contracted the red showed up, and the animals were 

 still in harmony with their surroundings ; if further irritated, the 

 edges of the salver-shaped margin were folded over and the anemones 

 then formed bluish purple patches against a dark background : possibly 

 a warning colouration. A second variant found in pools only a few 

 yards from those just mentioned was lighter in colour, more variegated, 

 and had the tentacles merely tinged with red, or not at all. This type 

 was found in pools wliere " corallines " were the main growth, and 

 when these specimens closed, their columns were of a pink shade 

 (seldom purple), and thus in accordance with the environment instead 

 of in contrast, as in the last examples. 



On muddy shores the summit is dark, as I have observed at 

 Plymouth, etc. These examples could be backed by many more from 

 varying localities. In all, the complex colouring of the disk and 

 tentacles approximates to the colour scheme of the pool, or portion of 

 pool in which the individual has its habitat. I quote from my 

 notes made on the rocks at Polzeath, near Padstow, Cornwall : 

 "C. pedunculatus is fairly abundant on this (the Pentire) side of the bay, 

 and I have examined a considerable number. The rocks hereabouts 

 are reddish or greenish, and the pools are often coated with pink 

 Algae. In the first I examined a dull red specimen was expanded, 

 and just the shade of numerous tufts of the brown seaweeds growing 

 around it; when closed the margin was of a pink hue, exactly that of 

 the rock around it. Near by were others growing amidst pink 



