A full-grown male Walrus measures from 10 to 11 feet from the nose to the end of the very short tail, and is a heavy, bulky animal, especially thick about the shoulders. The soles of both fore and hind feet are bare, rough, and warty. The surface of the skin generally is covered with short, adpressed hair of a light, yellowishbrown colour, which, on the under parts of the body and base of the flippers, passes into dark reddish-brown or chestnut. In old animals the hair becomes more scanty, sometimes almost entirely disappearing, and the skin shows ample evidence of the rough life and pugnacious habits of the animal in the innumerable scars with which it is usually covered. It is everywhere more or less wrinkled,

but especially over the shoulders, where it is thrown into deep and heavy folds.

The tusks are formidable weapons of defence, but their principal use seems to be scraping and digging among the sand and shingle for the molluscs and crustaceans on which the Walrus feeds. They are said also to aid in climbing up the slippery rocks and ledges of ice on which so much of the animal's life is passed. Although this function of the tusks is affirmed by numerous authors, some of whom appear to have had opportunities of actual observation, it is explicitly denied by Malmgren.

Walruses are more or less gregarious in their habits, being met with generally in companies or herds of various sizes. They are only found near the coast or on large masses of floating ice, and rarely far out in the open sea; and, though often moving from one part of their feeding ground to another, they have no regular seasonal migrations. Their young are born between the months of

April and June, usually but one at a time, never more than two. Their strong affection for their young, and their sympathy for each other in times of danger, have been particularly noticed by all who have had the opportunity of observing them in their native haunts. When one of their number is wounded, the whole herd usually join in a concerted and intelligent defence. Although harmless and inoffensive when not molested, they exhibit considerable fierceness when attacked, using their great tusks with tremendous effect either on human enemies who come into too close quarters or on Polar Bears, the only other adversaries they can meet with in their own natural territory. Their voice is a loud roaring, and can be heard at a great distance; it is described by Dr. Kane as something between the mooing of a cow and the deepest baying of a mastiff, very round and full, with its bark or detached notes repeated rather quickly seven or nine times in succession."

The principal food of the Walrus consists of bivalved molluscs, especially Mya truncata and Saxicava rugosa, two species very abundant in the Arctic regions, which it digs up from the mud and sand in which they lie buried at the bottom of the sea by means of its tusks. It crushes and removes the shells by the aid of its grinding teeth and tongue, swallowing only the soft part of the animal. It also feeds on other molluscs, sand-worms, star-fishes, and shrimps. Portions of various kinds of algae or sea-weeds have been found in its stomach, but whether swallowed intentionally or not is still doubtful.

The commercial products of the Walrus are its oil, hide (used to manufacture harness and sole-leather and twisted into tiller ropes), and tusks. The ivory of the latter is, however, inferior in quality to that of the Elephant. Its flesh forms an important article of food to the Eskimo and Tchuktchis. Of the coast tribes of the last-named people the Walrus forms the chief means of support. "The flesh supplies them with food, the ivory tusks are made into implements used in the chase and for other domestic purposes, as well as affording a valuable article of barter, and the skin furnishes the material for covering their summer habitations, harness for their dog-teams, and lines for their fishing gear" (Scammon).

Geographically the Walrus is confined to the northern circumpolar regions of the globe, extending apparently as far north as explorers have penetrated, but its southern range has been much restricted of late in consequence of the persecutions of man. On the Atlantic coast of America it was met with in the sixteenth century as low as the southern coast of Nova Scotia, and in the last century it was common in the Gulf of St. Lawrence and on the shores of Labrador. It still inhabits the coast round Hudson's Bay, Davis Straits, and Greenland, where, however, its numbers are daily decreasing. It is not found on the Arctic coast of America between the 97th and

158th meridians. In Europe occasional stragglers have reached the British Isles, and it was formerly abundant on the coasts of Finmark. It is rare in Iceland, but Spitzbergen, Nova Zembla, and the western part of the north coast of Siberia are still constant places of resort, in all of which a regular war of extermination is carried on. The North Pacific, including both sides of Behring's Strait, northern Kamschatka, Alaska, and the Pribyloff Islands, are also the haunts of numerous Walruses, which are isolated from those of the North Atlantic by the long stretches of coast, both of Siberia and North America, where they do not occur. The Pacific Walrus appears to be as large as, if not larger than, that of the Atlantic; its tusks are longer and more slender, and curved inwards; the whiskers are smaller, and the muzzle (of the skull) relatively deeper and broader. These and certain other minor differences have induced some naturalists to consider it specifically distinct under the name of Trichechus obesus. Its habits appear to be quite similar to those of the Atlantic form. Though formerly found in immense herds, it is rapidly becoming scarce, as the methods of destruction used by the American whalers, who have systematically entered upon its pursuit, are far more certain and deadly than those of the native Tchuktchis, to whom, as mentioned before, the Walrus long afforded the principal means of subsistence. Fossil remains of Walruses and closely allied animals have been found in the United States, and in England, Belgium, and France, in deposits of Pliocene age.

Family PHOCIDÆ.

The true Seals are the most completely adapted for aquatic life of all the Pinnipeds. When on land the hind limbs are extended behind them and take no part in progression, which is effected by a series of jumping movements produced by the muscles of the trunk, in some species aided by the fore limbs only. The palms and soles of the feet are hairy. There is no pinna to the ear, and no scrotum, the testes being abdominal. The upper incisors have simple, pointed crowns, and vary in number in the different groups. All the forms have well-developed canines and teeth of the cheekseries. In those species of which the milk-dentition is known, there are three milk molars (Fig. 275), which precede the second. third, and fourth permanent molars; the dentition is therefore p m, the first premolar having as usual no milk-predecessor. The skull has no postorbital process and no alisphenoid canal; and the angle of the mandible is not inflected. The fur is stiff and adpressed, without woolly under fur.

Subfamily Phocinæ.-Incisors 3. All the feet with five welldeveloped claws. The toes on the hind feet subequal, the first and

fifth not greatly exceeding the others in length, and with the interdigital membrane not extending beyond the toes.

Halichorus.-Dentition: i, c, pt, m; total 34. Crowns of molars large, simple, conical, recurved, slightly compressed,

FIG. 275.-Upper permanent and deciduous dentition of the Greenland Seal (Phoca grænlandica). The first and second deciduous incisors are already absorbed.

with sharp anterior and posterior edges, but without accessory cusps, except sometimes in the two hinder ones of the lower jaw. With the exception of the last one or two in the upper jaw and the last in the lower jaw they are all uniradicular. Vertebræ : C 7, D 15, L 5, S 4, C 14.

One species, H. grypus, the Gray Seal of the coasts of Scandinavia and the British Isles (see page 604.)

Phoca.2-Dental formula as the last. Teeth smaller and more pointed. Molars (Figs. 275 and 276) with two roots (except the first in each jaw); and their crowns with accessory cusps. Vertebræ C 7, D 15, L 5, S 4, C 12-15. Head round and short. Fore feet short, with five very

On the hind feet the claws much narrower and less curved. The species of this genus are widely distributed throughout the northern hemisphere, and include P. barbata, the Bearded Seal; P. græn landica, the Greenland Seal; P. vitulina, the Common Seal (Fig. 277); and P. hispida, the Ringed Seal of the North Atlantic; P. caspica, from the Caspian and Aral Seas; and P. sibirica, from Lake Baikal.

1 Nilsson, Faun. Scandinav. vol. i. p. 377 (1820).
2 Linn. Syst. Nat. 12th ed. vol. i. p. 55 (1766).

Although the members of this subfamily swim and dive with the greatest ease, often remaining as much as a quarter of an hour or more below the surface, and are dependent for their sustenance entirely on living prey captured in the water, yet they frequently resort to sandy beaches, rocks, or ice-floes, either to sleep or to bask in the sun, and especially for the purpose of bringing forth their young. The latter appears to be the universal habit, and, strange as it may seem, the young seals-of some species at least take to the water at first very reluctantly, and have actually to be taught to swim by their parents. The number of young produced is usually one annually, though occasionally two. They are at first covered with a coat of very thick, soft, nearly white fur, and until it falls off they do not usually enter the water. This occurs in the Greenland and Gray Seal when from two to three weeks old, but in the Common Seal apparently much earlier. One of this species born in the London Zoological Gardens had shed its infantile woolly coat and was swimming and diving about in its pond within three hours after its birth. The movements of the true Seals upon the ground or ice are very different from those of the Eared-Seals. Thus the hinder limbs (by which mainly they propel themselves through the water) are on land always perfectly passive, stretched backwards, with the soles of the feet applied to each other, and often raised to avoid contact with the ground. Sometimes the fore limbs are equally passive, being placed close to the sides of the body, and motion is then effected by a shuffling or wriggling action produced by the muscles of the trunk. When, however, there is any necessity for a more rapid mode of progression the animals use the fore paws, either alternately or simultaneously, pressing the palmar surface on the ground and lifting and dragging the body forwards in a succession of short jumps. In this way they manage to move so fast that a man has to step out beyond a walk to keep up with them; but such rapid action costs considerable effort, and they very soon become heated and exhausted. These various modes of progression appear to be common to all species so far as has been observed.

Most kinds of Seals are gregarious and congregate, especially at the breeding season, in immense herds. Such is the habit of the Greenland Seal (Phoca groenlandica), which resorts in the spring to the ice-floes of the North Sea, around Jan Mayen Island, where about 200,000 are killed annually by the crews of the Scotch, Dutch, and Norwegian sealing vessels. Others, like the Common Seal of the British islands (P. vitulina), though having a wide geographical range, are never met with in such large numbers or far away from land. This species is stationary all the year round, but some have a regular season of migration, moving south in