502 PROF, J, E, DUERDEN ON CRABS [ Dec, 12, 
carefully separate an actinian from its attachment (text-fig. 76). 
The crab moved round the actinian, inserting the tip of its limb 
at intervals, until in the end the polyp was dislodged, when it was 
seized and borne away, 
Text-fig, 76. 
Melia tessellata dislodging a fixed actinian by means of its first 
ambulatory limb. 
The crab Melia has thus the remarkable power of being able to 
detach a sea-anemone fixed to a substratum, proceeding in abso- 
lutely the same way as would a collector in endeavouring to secure 
the same kind of animal. Manifestly it is only by some such 
method that the actinian can be freed without injury, as the 
chele, along with the other appendages, are almost useless as 
grasping-organs. In other instances where crabs mask themselves 
by hydroid, sponge, or algal growths the fragments are simply 
torn away by the chelipeds, but the dislodgment of an entire 
actinian without injury and without the use of the claws is an 
operation much more complex in character, whether we regard it 
as an instinctive or an intelligent act. 
When first grasped by the crabs the sea-anemones were not 
necessarily held in the most favourable position, that 1s, across 
the middle of the column withthe disc directed upwards; at the 
beginning the chelz seized them in almost any fashion, so that 
the disc and tentacles were directed at anangle. In one instance, 
an actinian which had been thus grasped in an irregular manner 
was turned towards the maxillipeds and there held in position 
by the first ambulatory limbs; the chela was then freed from 
the actinian, cleansed thoroughly, and finally seized the actinian so 
that it was held across the middle with the dise directed upwards. 
There seems some evidence also that the actinians themselves 
institute righting reactions, such as they carry out under more 
natural conditions; so that, although at first grasped in any 
position, they are ultimately held across the middle with the 
