By the time she came below again, equipped for walking, Nellie's passing fit of ill-temper had disappeared, and she was not only her bright cheerful little self once more, but full of a project for adding to her collection a specimen of the `sea cucumber,' which the Captain had told her she might find if she only hunted diligently enough. These strange marine animals belong to a species of `Triple Alliance' of their own, being connected in a greater or less degree with the anemones, the ringworms, and the `sea urchins'; albeit, the sea cucumbers possess one very great advantage over these cousins of theirs, in being able, when they so please, to turn themselves inside out and dispense with their stomachs, as well as what would be considered other equally necessary portions of their corporate frames. When in this transformed, or `turn-coat' stage of his existence, the animal consists only of an empty bag, or pocket, that has at the broadest end an apparently useless mouth, but which he still continues to make use of for feeding purposes; and, by and by, when my gentleman feels disposed to return to his original state, seemingly by the mere effort of will, his tentacles sprout out one by one, the mouth-end of his bag becomes surmounted by a sort of mushroom head, his interior person gets filled up, and the sea cucumber is himself again, "all a- taunto!" The Captain had advised Nellie to search amongst the old wooden piles of the pier, as a likely situation to find these animals, and others he named quite as curious, such as the `beroe' and the `balanus,' which while looking as if inanimate yet are `all alive,' and, if not `kicking,' certainly may be seen fishing, either with natural lines of their own or with a sort of trawl-net, very similar to which we human bipeds use. But, although Miss Nellie, with Dick acting under her directions and Bob, too, assisting in a desultory way when the superior attractions of crab-hunting on his own account did not beguile him from the pursuit, all hunted everywhere, finding every variety of young whelks, cockles, and other shell-fish ova on the pier-piles, which they were able to examine at their pleasure, it being low tide, no sea cucumbers to be seen anywhere. Nellie was in despair at her failure and felt almost inclined to cry; but, Dick at the last moment, when the search was just about to be given up, raked out a perfect specimen from a hole in the rock-work beneath one of the buttresses that was nearly awash with the water--a darksome dungeon, isolated from the vulgar herd of barnacles, and common but kindred anemones with which the stuck-up sea cucumber was too proud to associate.