TIIICFUIA, in botany, a genus 'of the Monoecia .Tetrandria class and order. Natural order of Tricocue. Euphorbix, Jussieu. Essential character : male, ca lyx four-leaved ; corolla none ; filaments ovate ; female, calyx five-leaved ; corol la none ; styles conical ; capsule three horned, three-celled. There is only one species, viz. T. lxvigata, a native of Ja maica, in mountain coppices in the wes tern parts of the island, flowering in the spring months.
lRKllECUS, the walrus, in natural history, a genus of Mammalia of the or der Erma. Generic character : no fore teeth in the full grown animal, above or below ; tusks in the upper jaw solitary ; grinders with wrinkled surfaces ; body oblong ; lips doubled ; hind feet stretch ed, uniting into a tin. These animals are all natives of the sea, and feed on sea weeds and shell-fish, but are never knoWn to eat flesh. There are three species, of whiob the principal is T. ros marus, the arctic walrus, or the morse. This is an animal of a very inelegant structure. It has a small head to a vast body. Its under lip is covered with bris tles nearly of the thickness of a crow quill. In its upper jaw it has two large tusks from one to two feet in length, and weighing from three to twenty pounds. The walrus sometimes grows to ,the length of eighteen feet, and the circum ference, about the thickest part, of twelve. Pt is principally found in the high latitudes of the Northern Ocean. These animals are gregarious, and are of ten seen upon floating masses of ice, in immense numbers, the greater part sleeping, but some always on the watch, to give notice of approaching danger. They are harmless when not provoked ; but some accounts represent them as highly formidable in a state of irritation, the efforts of many being combined a gainst the enemy, and fastening 'with their teeth against boats to make holes in them, or draw them to the bottom. Others represent them as less agitated by the fury of passion, and as inclined more to flight than revenge, adding, that they are terrified by the slightest flash, and even the pointing of a musket will drive them in a moment out of sight. Their tusks serve the purposes of aiding their movements upon the ice, into which they are stuck, and on which they thus se cure their hold, and sometimes drag on their unweildv bodies. The tusks are
convertible to the purposes of ivory, and these animals are destroyed for the pro fit derivable partly from these tusks, but principally for the sake of their oil, of which a grown walrus will yield a butt. The skin maybe manufactured in to a very strong leather. The affection between the female and its young one, fbr it has seldom more than one at a birth, is such that they arc said never to sepafate, and that when one is killed the survivor refuses to quit-the dead body, and is considered by the hunter as his se cure prey. The walrus has been called, With little resemblance to justify the name, the sea. horse ; it is more similar to a cow, but most of all to a seal. See Mammalia, Plate XXI. fig. 3.
T. borealis, or the whale-tailed mans ti, inhabits the seas between Kamtschat ka and America. These animals live in families, generally consisting of a male and a female, and two young ones of dif ferent ages ; and the attachment of the male to the female is so great, that he will defend her when attacked to the last extremity ; and if she happens to be de stroyed and dragged to the shore, he will swim for tome days off the fatal and detested spot. The manati approaches very nearly to the' cete tribe, and its feet are little more than pectoral fins. It at tains the immense length of twenty-se ven feet, and the weight of four tons. In winter it is extremely lean, and its ribs may be distinctly numbered. It will, when pierced with the harpoon, some time adhere to rocks with itit feet with uncommon tenacity, and when forced from them by a cord drawn by thirty Men or more, is found to have left part of the skin of the feet behind. When any individual is harpooned, others are stat ed to swim to its aid, endeavouring, some to overturn the boat, others to break the cord, and others again, by blows with their tails, striving to dislodge the harpoon. Their sounds somewhat re sembling the snorting of a horse. They are never seen on land.