The Dentieete (Odontoceti, Delphinoidea) in clude, besides the toothed whales, all those other cetaceans known as dolphins, narwhals, por poises, killers, etc. The most important whale in this group is the sperm whale (Plipseter macrocephulus). also called cachalot and spermaceti whale. It has a very wide geographical range, occurring in all the important oceans, but it is most abundant off New Zealand, in the Sulu Sea, about the Cape Verde Islands, and in the Indian Ocean. It occurs more generally in the tropics and warm temperate seas than elsewhere. The sperm whale reaches a length of sixty feet or possibly more, but the female is much smaller than the male. The head is enormously large, about one-half of the entire bulk of the animal and occupying more than one-third of the entire length. From the head, the body tapers to the tail, and at last rather rapidly. The gen eral color is very dark gray. nearly black on the upper parts, lighter beneath. Old bull whales usually have a large gray spot on the front of the head. The muzzle is very obtuse, almost as if squarely cut off in front, the breadth of it almost equaling the thickness of the body. In a protuberance on the upper part of it is Ole blow hole, which is single. situated a little on the left side, and in form not unlike the letter S elongated. The mouth is very large and wide; and the throat, unlike that of the Greenland whale, is very wide, sufficiently so to admit the body of a man. The upper jaw projects some feet beyond the lower, and is destitute of teeth ; the lower jaw has from 20 to 25 teeth on each side, according to the age of the animal. The teeth are conical and slightly recurved, projecting about two inches from the gum. The lower jaw is extremely narrow, the two branches being in contact throughout the greater part of its length; it fits into a groove in the upper, in which are cavities for the teeth. The eyes are small, and placed far back in the head, above the angles of the mouth; the left eye is said to be smaller than the right. Just above the eyes, the dorsal line rises considerably; the dorsal fin is also represented by a protuberance about' half-way between the neck and the tail; and these parts are seen above water in the ordinary swimming of the animal, which is at the rate of from 3 to 7 miles an hour, and just under the surface of the water, although when alarmed it swims with greater velocity. The enormous head of the sperm whale is occupied in large part by an ag gregation of numerous small chambers separated and divided by connective tissue, in front of the cranium and above the upper jawbones. called IT whalers ale case, which are tilled with the spermaeeti; sometimes as much as ten barrels of it occur in a single ease. The blubber of the sperm whale is only about a foot thick and is not notably rich in oil, a large whale yielding about 100 barrels. When aroused these whales are dangerous adversaries, and either by biting or striking with the tail they can completely destroy whale boats, while by using the head as a ram they can sink small vessels. The remain ing Dentieete are mostly of small size and com paratively little importance. See DOLPHIN; POR POISE; NARWHAL; KILLER.
The Mysticete (Nystacoceti, Bakenoidea) in clude the true whales, those without teeth. They are nearly all of large size, some of them being the largest of living animals. The largest species is probably the sulphur-bottomed whale of the Pacific Ocean ( Sibbaldius sulf urcus) , which reaches a length of 90 feet or more. and the weight of which has been calculated to approach 150 tons. Several genera of whalebone whales are recognized, but the most important is Baluena, to which belong those species that supply the most valuable whalebone and oil. The most im portant species is the Greenland or Arctic right whale (Bakena mysticetus), which is circum polar in its distribution, but does not range far to the southward, preferring the regions of ice bergs and ice-floes. It attains a size of sixty or seventy feet in length. The body is thickest a little behind the 'flippers,' or pectoral fins, taper ing conically toward the tail, and slightly toward the head. The tail is five or six feet long, and from twenty to twenty-five feet broad, formed of two diverging lobes, broadest almost where they are united, but with a slight indentation. The
pectoral fins are eight or nine feet long and four or five feet broad. The mouth is fifteen or sixteen feet long. The eyes, which are situated on the sides of the head, about a foot above and rather behind the angles of the mouth. are not larger than those of an ox; but the sense of sight seems to be acute, at least in the water. The blow-holes are situated on the most elevated part of the head; they are from eight to twelve inches long, but of comparatively small breadth. The upper parts are velvety black, the lower. parts white. The upper parts, in very old whales, sometimes become piebald, the black being mixed with white and gray. The period of gestation is uncertain; one young is produced at a birth, and is from ten to fourteen feet in length when born. The mother displays great affection for her offspring, of which whale-fishers sometimes take advantage, harpooning the young one—itself of little value— in order to secure the mother. Suckling is per formed at the surface of the water, and the mother rolls from side to side, that she and the young one may he able to breathe in turn. The usual rate of progress in swimming is about four or five miles an hour. and whales often swim not far beneath the surface of the water, with the mouth wide open to take in water from which to sift food. This whale is capable. how ever, of swimming with much greater rapidity. Its tail is extremely powerful, and a single blow of it is sufficient to destroy a large boat. Whales usually come to the surface to breathe at in tervals of eight or ten minutes, but they are capable of remaining under water for half an hour or more. When they come up to breathe, they generally remain on the surface about two minutes, (hiring which they blow eight or nine tittles, and then descend. The noise which they make in blowing is very loud, and the spout of spray ejected ascends several yards into the air, appearing at a distance like a puff of smoke. They often assume, as if in sport, a vertical posi tion, with the head down, and flap the surface of the water with the tail, making a sound which is beard Iwo or three miles off. The Green land whale is not properly gregarious. being gen erally found alone or in pairs, except when num bers are attracted to particular feeding-grounds, as is sometimes the case in the bays and inlets of northern coasts.
A closely related and very important species is the southern right whale (Italwnu nustralis), which has a smaller head, shorter baleen, and it differently shaped under lip. It has fifteen dor sal vertebra. and ribs, while the Greenland whale has generally only twelve. The southern right whale is found in all temperate seas in both the northern and southern hemispheres. although generally wanting in the tropics, and is not known to occur in the Antarctic Ocean. The right whales of the North Atlantic have been separated from those of the South Atlantie, and both from the Paeitie ocean forms, as distinct species, hut the differences are slight and inconstant. All of the right whales have been, and are still to a certain extent, pursued by whalers, and their numbers accordingly have become greatly re duced during the past century, and the North Atlantic form is now very rare. The. smallest of the whalebone whales is the New Zealand right whale (Ncolthenu niangimito), which reaches a length of only about 20 feet. Other whales of this same family are the gray whale (Rhackianectcs glaucvs) of the North Pacific, the baleen of which is very short and coarse; the hump-back whales. of the genus i\legaptera, which are nearly as large as the Greenland whale and have black baleen; and the rorquals of the genera Balamoptera and its allies. The rorquals (q.v.) are the largest whales and have a distinct and falcate dorsal fin. The pectoral fins are rather small and the skin of the throat is pli cated, as is the case with the hump-backs, which, however, have very large pectoral fins. The quals are the most abundant and widely distrib uted of whales at the present time, as it is only recently that they have been sought by the whalers. The blue whale (Bahama Sibbuldi) is the largest of the North Atlantic forms, while the sulphur-bottom, already referred to. re places it in the North Pacific. The fossil re mains of Ivhales occur in the Pliocene and later strata. See CETACEA.