1905.] BEARING ACTmiA^TS IX THEIR CLAWS. 497 



are slender and feeble — ill-suited for defence, but at the same 

 time mobile and well adapted to wield the anemones they cai-ry ; 

 and, if the crab be threatened, it will stretch out its arms towards 

 the aggressor, as though it would ward him off with the dis- 

 agreeable obstacles it thus presents to his attack. Certainly the 

 fingers cannot be used to take food unless the anemone be first 

 dropped ; but, on the other hand, the tentacles of the latter are 

 directed outwards, away from the mouth of the crab. The third 

 maxillipeds are mobile, with the proximal joints rather slender 

 and the last three stout, and are fringed with long hairs. 

 Possibly they are used to catch small organisms for food in much 

 the same way as those of the China Crabs (Porcellanidfe), which 

 part wdth their chelipeds so readily when they are attacked, 

 since they do not use them for taking food. 



" In any case we seem to have here an interesting example of 

 the use of an implement by an animal which, however intelligent, 

 has at least a very differently organised nervous system fi'om the 

 Vertebrata. It should be noted that the case is different fi'om 

 that of a Spider-crab, which sticks pieces of seaweed on its back 

 and enjoys passively the concealment gotten thereby. For the 

 Melia carries the anemone in its cheliped — the chief grasping- 

 organ of the animal, corresponding to the hand of a primate or 

 the trnnk of an elephant — and, whatever its lase, it cannot be 

 a means of passive concealment, to which its size is wholly 

 inadequate." 



These two accounts leave much to be desired ere we can be said 

 to have a complete acquaintance with the living relationships 

 between Melia and its associated actinians, and their peculiarities 

 of habits and reactions. 



A short time ago Miss M. J. Rathburn, of the United States 

 ISTational Museum, forwai-ded me for identification the actinians 

 held in the claws of a specimen of Melia. The crab had been col- 

 lected at Hilo Bay, Hawaiian Islands, by Prof. Henshaw, and the 

 actinian proved to belong to a sj)ecies of Bunodeojysis, a genus w^ell 

 known as occurring in the Mediterranean and the West Indies. 

 During a recent visit by the author to the Hawaiian Islands, 

 under the auspices of the Carnegie Institution, for the purpose of 

 studying the living corals, an effort was also made to procure 

 other specimens of Melia and its commensal actinians. On the 

 second day's collecting over the reef-flats at Waikiki Beach, near 

 Honolulu, a single crab carrying actinians (text-fig. 74, p. 498) 

 was obtained, and another a few days later. During all the sub- 

 sequent collecting, extending over three months, at various points 

 of the islands, no other Melias w^ere seen, so that evidently the 

 species is not so common in Haw^aiian waters as in the regions 

 visited by Mobius and Borradaile. 



Both specimens of Melia were found on the dead under surface 

 of coral blocks, not wandering among the branches of the living- 

 coral as in Borradaile's expei^ience. Further, Prof. Henshaw, 

 who has on rare occasions collected the crab at Hilo Bay, also 



