There goes a military cousin of his, striding along, with his heavy armor clattering against the glass as he walks. A pugnacious fellow is that same soldier; and if he meet an opponent, you may see the tug of war. Should he chance to prefer the other's shield to his own, he will seize him in his burly arms, and shake him from under its protection. Yet he is cautious withal; for though obliged to doff his own armor before he can try that of his denuded foe, he retains hold of both until satisfied with the trial. If he like the new mail, he will march off with it; if not, he will array himself in his own again. Meanwhile the vanquished combatant waits tremblingly the result of the examination, glad to get possession of the rejected defence, be it which it may. Yon dark little crab, with the bulky claws so gayly mottled with yellow and black, lurks in that hole at the base of the cliff nearly all day long. His name is 'Possum; for at the slightest sign of danger he doubles up his claws like a dead spider, and lies in feigned lifelessness. Speaking of spiders,--here are two Spider-Crabs, the very monkeys of this aqueous menagerie. The small one climbing the post is Topsy. There she is, sliding down again, and with headlong pace is now scampering over yon yielding Anemone. Heedless of its hundred arms, so generally dreaded and avoided, she jumps this way and that across its wide mouth; and now, seated on its back, she snatches morsels from its shrinking side. Now look at her sister sprite, Crazy Kate. Her head adorned with a long plume of Coralline, she is tearing ribbon-like shreds from the silky lettuce and hanging them upon her already fantastic person. Anon she dances in mad glee, and next her arms are solemnly stretched upward in grotesque similitude to one in prayer. When she is hungry, she will, one by one, take off those weedy trophies from her back and feed upon them. Why do you start? That is not a sea-serpent winding from under the arch, but only an innocent Eel. Yet innocent and tiny though it be, there is something frightful about it. Its fixed, staring eye, its snake-like stealthiness, bid you be on your guard. Sometimes it rises behind that bushy Carrageen, and with high uplifted head peers over at me in such a way that I am half afraid; it is so like the old pictures of Satan tempting Eve. Would you like to see an Actinia eat? I will drop a bit of raw oyster upon its outspread disk. See with what eager start it closes its fingers about the dainty viand, passing it along slowly, but surely, to its now gaping mouth, while every nerve is vibrating with the anticipated pleasure of the feast! That milk-white one is my favorite, and I call it Una. Seated in modest contentment on that brown-stone seat, she upturns her pure face to the mild light of evening; but folds her arms, and bows her head, and veils herself, when the noon-day sun gazes too ardently upon her.