The second specimen, although equally grimy, had some redeeming points in his personal appearance, for at intervals every part of his back and claws were covered with small frondlets of ulva, dulse, D. sanguinea, and other beautiful weeds, all of which were in a healthy condition. After keeping him in a vase for a week, he managed, much against my wish, to strip himself of the greater part of these novel excrescences.
Instead of minute algæ, we read that these crabs are sometimes found with oysters (Ostrea edulis) attached to their backs. Mr. W. Thompson mentions two instances where this occurs, with specimens of H. araneus, to be seen in Mr. Wyndman's cabinet. Speaking of these, he adds, 'The oyster on the large crab is three inches in length, and five or six years' old, and is covered with many large Balani. The shell, a carapace of the crab, is but two inches and a quarter in length, and hence it must, Atlas-like, have born a world of weight upon its shoulders. The presence of the oyster affords interesting evidence that the Hyas lived several years after attaining its full growth.
For days after I had brought him home, my second specimen appeared as if he were dead, and it was only by examining his mouth through a hand lens that I could satisfy myself as to his being alive. When I pushed him about with an ivory stick he never resisted, but always remained still upon the spot where I had urged him.
This species of acting he has given up for some time, and at the present moment I rank H. araneus among my list of marine pets, for he does not appear any longer to pine for mud with which to decorate his person, but is quite content to 'purge and live cleanly' all the rest of his days.
The ancients imagined that Maia squinado possessed a great degree of wisdom, and further believed him to be sensible to the divine charms of music. It is very curious, as well as true, that this animal has in a far higher degree than other crustaceans, a gravity of demeanour, and a profound style of doing everything, that always excites our irreverent laughter, but at the same time leaves an impression that, if justice were done, the animal ought to hold a higher position in the marine world than a scavenger and devourer of ocean garbage. If Maia and C. mænas be both eating out of the same dish, in the shape of an open mussel, the former seems ever inclined to admonish his companion upon greediness and want of manners. The only seeming reason why M. squinado does not really give such advice, is because of the impossibility of any individual speaking with his mouth full. The knowledge, too, that if he commenced a pantomimic discourse, it would give his young friend an opportunity of gaining too large a share of the banquet, may, perhaps, have something to do with his preferring to remain quiet.
As for Maia's possession of appreciative musical qualities, I can only state that both he and his friend Hyas really do convey to the beholder an impression confirmatory of this statement. I have frequently been amused to observe the singular phenomenon of each animal coming to the side of the vase and rocking his body to and fro, in apparent delight at the exercise of my vocal abilities, just as when a pleasing melody is being played in the concert room, we bend backwards and forwards, and beat time to the tune. These animals also adopt the same course: it must be to unheard music (which the poets say is sweetest), that seems ever and anon to fall on their ears, giving them great delight.
The movements here alluded to may be in no way influenced by music; but such as they are, it is curious that they have not been noticed as an apparent explanation of the origin of the ancient belief regarding the Spider-Crabs.
A friend, on one occasion having procured for me, among other objects, a Common Limpet, I placed this mollusc in my aquarium, and soon had the pleasure of watching it affix its broad foot to the surface of the glass. After a while, on the Limpet slightly raising its canopy, I was surprised to observe a little Shore-Crab peer out from between the foot and shell. On suddenly ejecting the intruder by means of a small brush, he speedily hid himself from view among the surrounding pebbles. A few hours after, on again approaching the tank to view the Patella (which was easily identified, from the fact of an immense colony of Mussels being settled on its back), I found to my great astonishment that the crab had re-seated himself in his old position. I often repeated the sweeping operation, but without success, for the little rascal had become artful, and was not inclined to be driven forth a second time by a coup de main. I touched the Limpet frequently and saw it glue itself, as usual, to the glass; but, singular to state, the creature always left a larger space between its foot and the circumference of the shell on the side at which the crab was seated, than on the opposite one, seemingly from a wish to accommodate its crustaceous friend. This space, moreover, let me observe, was larger than was absolutely necessary, for, as the shell was not air-tight, I was enabled to thrust my camel-hair pencil teazingly upon the crab, and was much amused to watch him clutch at the intruding object, and, at times, move about with it in his grasp, thus proving that he was by no means uncomfortably 'cabin'd, cribb'd, confin'd.'
For a whole week the crab remained in his favorite lodgings, and only resigned occupancy thereof when his friend gave up the shell—and died.