its head! “The necessity of this position for the feet arises probably from the close investment of the mantle over the body; for, although the mantle leaves an aperture in the neck for the entrance of water to the respiratory organs, yet in other respects it forms a sack, closed in every part except where the head, neck, and accompanying tentacula protrude. “In the _calamary_, as well as the common _sepia_, two of the arms are much longer than the rest, and terminate in a thick cylindrical portion, covered with numerous suckers, which may not inaptly be compared to a hand. These processes are employed by cuttle-fish as anchors, for the purpose of fixing themselves firmly to rocks during violent agitations of the sea; and accordingly we find that it is only the extremities of these bony tentacula that are provided with suckers, while the short ones have them also along their whole length. The other genera of _cephalopodous mollusca_ are, like the _sepia_, provided with tentacula attached to the head. They comprehend animals differing exceedingly in size, some being very large, but a great number very minute, and even microscopic.” Other animals of this kind inhabit shells, one of which is the nautilus, which, says Roget, “possesses a shell exceedingly thin and almost pellucid; probably for the sake of lightness, for it is intended to be used as a boat. For the purpose of enabling the animal to avail itself of the impulses of the air while it is thus floating on the water, Nature has furnished it with a thin membrane, which she has attached to two of the tentacula, so that it can be spread out like a sail to catch the light winds which waft the animal forward on its course. While its diminutive bark is thus scudding over the surface of the deep, the assiduous navigator does not neglect to apply its tentacula as oars on either side, to direct as well as to accelerate its motion. No sooner does the breeze freshen and the sea become ruffled than it hastens to take down its sail, and, quickly drawing its tentacula within its shell, renders itself specifically heavier than the water, and sinks immediately into more tranquil regions beneath the surface.” Sir William Jardine, in speaking of the food of the sperm whale,[4] ventures to suggest to those who may have frequent opportunities of observing whether this whale may not also frequently resort to the _medusæ_, and minute fish which in so remarkable a manner supply food to some of the smaller, as well as the other genera of the gigantic whales. That there is an abundant supply of this sustenance, both in the Antarctic Ocean and the more smiling latitudes of the southern seas, can easily be proved by a reference to _Lesson’s Statements_, and also to the _Journal_ of Captain Colnett, who, when near the southern point of America, observes: “During this forenoon we passed several fields of spawn, which caused the water to bear the appearance of barley covering the surface of a bank.”