The Greenland, or more properly Arctic, Right Whale (Balæna mysticetus) attains, when full grown, a length of from 45 to 50 feet. Its usual vertebral formula is C 7, D 12, L 14, C 22. The external form is shown in Fig. 76 from a careful drawing by Mr. Robert Gray. In this species all the peculiarities which distinguish the head and mouth of the Whales from those of other mammals have attained their greatest development. The head is of enormous size, exceeding one-third of the whole length of the creature. The cavity of the mouth is actually larger than that of the body, thorax and abdomen together. The upper jaw is very narrow, but greatly arched from before backwards, to increase the height of the cavity and allow for the great length of the baleen blades; the rami of the mandible are widely separated posteriorly, and have a still further outward sweep before they meet at the symphysis in front, giving the floor of the mouth the shape of an immense spoon. The baleen blades attain the number of 380 or more on each side, those in the middle of the series having a length of 10 or sometimes 12 feet. They are black in colour, fine and highly elastic in texture, and fray out at the inner edge and ends into long, delicate, soft, almost silky, but very tough, hairs. The remarkable development of the mouth and the structures in connection with it, which distinguishes the Right Whale among all its allies, is entirely in relation to the nature of its food. It is by this apparatus that the animal is enabled to avail itself of the minute but highly nutritious crustaceans and pteropods which swarm in immense shoals in the seas it frequents. The large mouth enables it to take in at one time a sufficient quantity of water filled with these small organisms, and the length and delicate structure of the baleen provide an efficient strainer or hair-sieve by which the water can be drained off. If the baleen were rigid, and only as long as is the aperture between the upper and lower jaws when the month is shut, a space would be left beneath it when the jaws were separated, through which the water and the minute particles of food would escape together. But instead of this the long, slender, brush-like, elastic ends of the whalebone blades fold back when the mouth is closed, the front ones passing below the hinder ones in a channel lying between the tongue and the lower jaw. When the month is opened, their elasticity causes them to straighten out like a bow unbent, so that at whatever distance the jaws are separated the strainer remains in perfect action, filling the whole of the interval. The mechanical perfection of the arrangement is completed by the great development of the lower lip, which rises stiffly above the jaw-bone and prevents the long, slender, flexible ends of the baleen from being carried outwards by the rush of water from the mouth, when its cavity is being diminished by the closure of the jaws and raising of the tongue.

If, as appears highly probable, the “bowhead” of the Okhotsk Sea and Behring Strait belongs to this species, its range is circumpolar. Though found in the seas on both sides of Greenland, and passing freely from one to the other, it is never seen so far south as Cape Farewell; but on the Labrador coast, where a cold stream sets down from the north, its range is somewhat farther. In the Behring Sea, according to Scammon, “it is seldom seen south of the fifty-fifth parallel, which is about the farthest southern extent of the winter ice, while on the Sea of Okhotsk its southern limit is about the latitude of 54°.” As has been abundantly shown by Eschricht and Reinhardt in the case of the Greenland seas, “everything tends to prove,” Scammon says, “that the Balæna mysticetus is truly an ‘ice whale,’ for among the scattered floes, or about the borders of the ice-fields or barriers, is its home and feeding-ground. It is true that these animals are pursued in the open water during the summer months; but in no instance have we learned of their being captured south of where winter ice-fields are occasionally met with.” The occurrence of this species, therefore, on the British or any European coast is exceedingly unlikely, as when alive and in health the southern limit of its range in the North Sea has been ascertained to be from the east coast of Greenland at 64° N. lat. along the north of Iceland towards Spitsbergen, and a glance at a physical chart will show that there are no currents setting southwards which could bear a disabled animal or a floating carcase to British shores. To this à priori improbability may be added the fact that no authentic instance has been recorded of the capture or stranding of this species upon any European coast; for the cases in which it has been reported as seen in British waters may be explained by the supposition of one of the other species of the genus being mistaken for it. Still, as two other essentially Arctic Cetaceans, the Narwhal and the Beluga, have in a few undoubted instances found their way to British shores, it would be rash absolutely to deny the possibility of the Greenland Right Whale doing the same.

The southern Right Whale (B. australis, Fig. 77) resembles the last in the absence of dorsal fin and of longitudinal furrows in the skin of the throat and chest, but differs in that it possesses a smaller head in proportion to its body, shorter baleen, a different shaped contour of the upper margin of the lower lip, and a greater number (fifteen) of ribs and dorsal vertebræ. This form inhabits the temperate seas of both northern and southern hemispheres, and is divided into several so-called species, according to their geographical distribution:—B. biscayensis of the North Atlantic, B. japonica of the North Pacific, B. australis of the South Atlantic, and B. antipodarum and B. novæ-zealandiæ of the South Pacific. The differential characters by which they have been separated, external as well as anatomical, are, however, slight and subject to individual variation; and the number of specimens available for comparison in museums is not yet sufficient to afford the necessary data to determine whether these characters can be regarded as specific or not. The most interesting of these is the Atlantic Right Whale, which was formerly abundant in the North Atlantic, but is now so scarce as to appear verging on extinction. This was the Whale the pursuit of which gave occupation to a numerous population on the shores of the Basque provinces of France and Spain in the Middle Ages. From the tenth to the sixteenth centuries Bayonne, Biarritz, St. Jean de Luz, and San Sebastian, as well as numerous other towns on the north coast of Spain, were the centres of an active Whale “fishery,” which supplied Europe with oil and whalebone. In later times these Whales were pursued as far as the coast of Newfoundland. They were, however, already getting scarce when the voyages undertaken towards the close of the sixteenth century for the discovery of the north-eastern route to China and the East Indies opened out the seas around Spitzbergen; then for the first time the existence of the Greenland Whale became known, and henceforth the energies of the European whale-fishers were concentrated upon that animal. It is a singular fact that the existence of the Atlantic Right Whale was quite overlooked by naturalists till lately, all accounts referring to it being attributed to the Greenland Whale, supposed once to have had a wider distribution than now, and to have been driven by the persecution of man to its present circumpolar haunts. To the two Danish cetologists Eschricht and Reinhardt is due the credit of having proved its existence as a distinct species, from a careful collation of numerous historical notices of its structure, distribution, and habits; and their restoration of the animal, founded upon these documents, has been abundantly confirmed by the capture of various specimens in recent times, showing that it still lingers in some of the localities where it formerly was so abundant. The only known instances of its occurrence on the coasts of Europe in modern times are in the harbour of San Sebastian in January 1854, in the Gulf of Taranto, in the Mediterranean, in February 1877, and on the Spanish coast between Guetaria and Zarauz (Guipuzcoa) in February 1878. The skeletons of these three whales are preserved in the museums of Copenhagen, Naples, and San Sebastian respectively. On the coast of the United States several Whales of this species have been taken within the last few years. In the North Pacific a very similar if not identical species is regularly hunted by the Japanese, who tow the carcases ashore for the purposes of flensing and extracting the whalebone. In the tropical seas, however, according to Captain Maury’s whale charts, Right Whales are never or rarely seen; but the southern temperate ocean, especially the neighbourhood of the Cape of Good Hope, Kerguelen’s Island, Australia, and New Zealand, is inhabited by “Black Whales,” once abundant, but now nearly exterminated through the wanton destruction of the females as they visit the bays and inlets round the coast, their constant habit in the breeding time. The range of these Whales southward has not been accurately determined; but no species corresponding with the Arctic Right Whale has as yet been met with in the Antarctic icy seas.

Remains of Right Whales are of not uncommon occurrence in the Pliocene Crag deposits of England and Belgium. The tympanics of B. affinis from these deposits appear to indicate a species closely allied to B. mysticetus, in which this bone is long and angulated anteriorly (Fig. 78); while the tympanics from the same deposits described as B. primigenia are shorter and more rounded at the antero-inferior angle, thus resembling those of B. australis. A smaller species, having an estimated length of about 20 feet, has been described as Balænula balænopsis, the generic distinction being made on account of the free condition of the atlas and seventh cervical vertebræ; but it seems scarcely advisable to regard such a feature as indicating more than a less specialised species. Balæna (Balænotus) insignis is a whale of somewhat larger dimensions, in which the atlas is generally, and the seventh cervical vertebra always, free, while in young individuals the axis vertebra may likewise be separate.

Neobalæna.[132]—Head about one-fourth the total length. Skin of the throat not plicated. A small falcate dorsal fin. Vertebræ, C 7, D 17, L 3, C 16 = 43. The cervical vertebræ are united. The manus small, narrow, and tetradactylous, wanting the pollex. The ribs remarkably expanded and flattened. The scapula very low and broad, with completely developed acromion and coracoid processes. Tympanic approximating to that of Balæna, but with certain very characteristic peculiarities of shape. Baleen very long, slender, elastic, and white. A single species, at present very rare, N. marginata, from the Australian and New Zealand seas is the smallest of the Whalebone Whales, being not more than 20 feet in length.

Rhachianectes.[133]—This combines the small head, elongated form, and narrow pectoral fin of Balænoptera with the smooth skin of the throat and absence of the dorsal fin of Balæna. The baleen is the shortest and coarsest of any of the group. Its osteology is imperfectly known. One species, R. glaucus, the Gray Whale of the North Pacific.

Megaptera.[134]—Head of moderate size. Baleen plates short and broad. Vertebræ, C 7, D 14, L 11, C 21 = 53. Cervical vertebræ free. Scapula with acromion and coracoid process absent or rudimentary. Skin of throat plicated. Dorsal fin low. Pectoral limb tetradactylous, very long and narrow, attaining about one-fourth of the length of the entire animal, the metacarpus and phalanges being greatly developed, and the latter very numerous. Tympanic still more inflated than in Balænoptera, with the involuted portion more distinctly pyriform, the Eustachian part of the aperture well defined, and two well-marked longitudinal ridges on the lower surface of adult specimens.

The Whale commonly called “Humpback” (Megaptera boops) by whalers, perhaps on account of the low hump-like form of the dorsal fin, is very distinctly characterised from all others of the group, especially by the immense length of the pectoral fins or flippers, which are indented or scalloped along their margins, and are, except at their base, of a white colour, nearly all the rest of the body being black. The baleen plates are of a deep black colour. Though common in the North Atlantic between Norway and Greenland, this Whale does not frequently appear on the coasts of the British Isles. One came ashore at Newcastle in 1839; another, a young one, was taken in the estuary of the Dee in 1863, and its skeleton is preserved in the Liverpool museum; and a nearly full-grown animal was captured in the mouth of the Tay in the winter of 1883-84.[135] The usual length of the adult ranges from 45 to 50 feet, the female being larger than the male. Whales of the genus Megaptera are found in the South Atlantic and in both the North and the South Pacific. They resemble those of British seas so closely that it is doubtful whether the differences which have been observed, and upon which several species have been founded, may not be individual peculiarities; but zoologists have not yet had the opportunity of examining and comparing such a series of specimens of different ages and sexes from different localities as would be necessary to determine these points satisfactorily.

Tympanic bones of Megaptera occur in the English and Belgian Crags, although somewhat less commonly than those of Balæna and Balænoptera; they have been described under the names of Megapteropsis and Burtinopsis.

Balænoptera.[136]—Head small and flat, and pointed in front. Body long and slender. Skin of throat plicated. A small falcate dorsal fin. Baleen short and coarse. Cervical vertebræ free. Scapula low and broad, with a large acromion and coracoid process. Pectoral limb tetradactylous, small, narrow, and pointed. Tympanic (Fig. 81) long, much inflated, and rounded, with the involuted portion thickened and pyriform, and the notch for the Eustachian canal sharply defined; inner surface flattened, without the vertical groove found in Megaptera.

The Rorquals, Fin-Whales, Fin-backs, Finners, or Razor-backs, as they are variously called, have the plicated skin of the throat like that of Megaptera, the furrows being more numerous and close set; but the pectoral fin is comparatively small, the dorsal fin distinct and falcate, and the tail very much compressed before it expands into the “flukes.” The Rorquals are perhaps the most abundant and widely distributed of all the whales, being found in some of their modifications in all seas, except the extreme Arctic, and probably Antarctic regions. Owing to the small quantity and inferior quality of their whalebone, the comparatively limited amount of blubber, and their great activity and the difficulty of capturing them by the old methods, these Whales were not until recently an object of pursuit by whale-fishers; but, since the introduction of steam-vessels, and especially of explosive harpoons fired from guns in the place of those hurled by the human hand, a regular fishery has been established on the coast of Finmark. There are four distinct species of this genus in British seas. (1) Balænoptera sibbaldi, the “Blue Whale,” the largest of all known animals, attains a length of 80 or even sometimes 85 feet. Its colour is dark bluish gray, with small whitish spots on the breast; the baleen is black; the flippers are larger proportionally than in other Rorquals, measuring one-seventh of the total length of the body; and the dorsal fin is small and placed very far back. This Whale has usually 64 vertebræ, of which 16 bear ribs. Like the others of the genus, this species seems to pass the winter in the open seas, and approaches the coast of Norway at the end of April or beginning of May. At this time its sole food is a small crustacean (Euphausia inermis) which swarms in the fjords. Several specimens have been taken on the British coasts, two fine skeletons from the Firth of Forth being preserved in the Edinburgh museums. (2) Balænoptera musculus, the Common Rorqual, has a length of 65 to 70 feet, is of a grayish slate colour above and white underneath, and the baleen is slate colour variegated with yellow or brown. It has usually 62 vertebræ, of which 15 bear ribs. This is the commonest of all the large Whales on the British coasts, scarcely a winter passing without the body of one being somewhere washed ashore, usually after stormy weather, and more frequently on the south coast, as this species has a more southern range than the last, and frequently enters the Mediterranean. It feeds largely on fish, and is frequently seen feasting among shoals of herring. (3) Balænoptera borealis, often called Rudolphi’s Whale from its first describer, is a smaller species, scarcely attaining a length of 50 feet. It is bluish-black above, with oblong, light-coloured spots, whilst the under parts are more or less white; the whole of the tail and both sides of the flippers are black; the baleen is black, and the bristly ends fine, curling, and white; the flippers are very small, measuring one-eleventh of the total length of the body. There are 56 vertebræ, with 14 pairs of ribs. This species, according to Collett, feeds chiefly on minute crustaceans, mainly Calanus finmarchicus and Euphausia inermis, and not on fish. Until lately it was considered the rarest of the Whales of European seas, and was only known to science from a few individuals stranded on the coasts of northern Europe at long intervals, the skeletons of which have been preserved in museums. The most southern point at which it has been met with hitherto is Biarritz in France. Since the establishment of the whaling station near the North Cape it has been shown to be a regular summer visitor, and in 1885, 771 individuals were captured on the coast of Finmark. (4) Balænoptera rostrata, the lesser Fin-Whale or Rorqual, is the smallest species found in the northern seas, rarely exceeding 30 feet in length. Its colour is grayish-black above, whilst the under side is white, including the whole of the lower side of the tail; the inner side of the flippers is white; and there is a broad white band across the outer side, which is a very characteristic mark of the species; the baleen is yellowish-white. The dorsal fin in this and the last species is comparatively high, and placed far forwards on the body. This Whale has usually 48 vertebræ, 11 of which bear ribs. It is common in summer in the fjords of Norway, and is often seen around the British Isles. It has been taken, though rarely, in the Mediterranean; and ranges as far north as Davis’s Straits.

Rorquals are met with in almost all seas throughout the world, but further and more accurate observations are required before their specific characters and geographical distribution can be made out. Nearly all the individuals hitherto examined with any care, whether from the North Pacific, the Australian seas, or the Indian Ocean, come very near in structure to one or the other of the Atlantic forms described above, so much so that some zoologists have been induced to believe that there are but four species, each of which has a wide, almost cosmopolitan range, while others have described and named almost every individual specimen captured as belonging to a different species.[137]

Tympanics, vertebræ, and other bones of Rorquals are among the commonest cetacean remains found in the Pliocene Crags of England and Belgium. Several species, varying in dimensions, are known from these deposits, B. definita (sibbaldina) being apparently nearly related to the existing B. sibbaldi. A caudal vertebra from the Upper Eocene of Hampshire has been referred to Balænoptera, but does not afford sufficient evidence to prove the existence of the genus at that date.

Extinct Genera.—The extinct genus Cetotherium of the European Pliocene may be taken to include a number of fossil Whalebone Whales allied to the Balænopterine group, several of which have been described under other names, such as Plesiocetus, Heterocetus, and Amphicetus. They are readily characterised by the form of the tympanic bone, which is much narrower in front than behind, the roughened inferior surface being in the shape of an isosceles triangle, and the notch for the Eustachian canal being smaller, and descending nearer to the inferior border of the inner wall than in Balænoptera. The skull is longer than the latter, with a greater interval between the occiput and the frontal, and with longer and more flattened nasals. The relative thickness of the cervical vertebræ is also greater. In the typical forms (e.g. C. brialmonti and C. dubium) the mandibular condyle is simple; but in C. (Heterocetus) brevifrons it is furnished with a projecting posterior talon, as in the Sperm Whale.

Herpetocetus is known by a comparatively small species from the Belgian and English Crags, characterised by the extreme inflation of the egg-shaped tympanic bone, which approximates to that of Megaptera, but has the greater part of the cavity filled by bone. There is a talon to the condyle of the mandible.

Palæocetus, as already mentioned (p. 232), is founded upon the ankylosed cervical vertebræ of a small Whale originally considered as having been derived from the Kimeridge Clay, but which doubtless came from the Suffolk Crag; if it belongs to the Balænidæ it indicates a Right Whale.

Suborder Archæoceti.

Family Zeuglodontidæ.

This group is formed to include certain extinct Cetacean-like animals at present only known by more or less fragmentary portions of their skeleton and teeth, and whose position and affinities are, therefore, still subject to doubt.[138]

In the anterior part of both jaws the teeth are simple, conical, or slightly compressed, and sharp pointed. The first three in the upper jaw are distinctly implanted in the premaxillary bone, and so may be reckoned as incisors. The tooth which succeeds, or the canine, is also simple and conical, but it does not exceed the others in size. This is followed by five teeth having two distinct roots and compressed pointed crowns, with denticulated cutting-edges. The dentition is therefore i ³⁄₃, c ¹⁄₁, p and m ⁵⁄₅ = 36, resembling that of some Seals.[139] General form of the skull elongated and much depressed. Brain-cavity very small, and the skull between it and the orbits elongated and narrow. Temporal fossæ very large. A strong sagittal crest. Rostrum long and narrow, differing from that of other Cetaceans in the large extent to which the premaxillæ form the sides of the anterior extremity. Nasal bones elongated, flat, and narrow, the opening of the anterior nares being over the middle of the elongated compressed rostrum. All the cervical vertebræ free. The characters of the dorsal vertebræ and mode of articulation of the ribs appear to have resembled those of Platanista rather than Balæna, Physeter, or Delphinus. Lumbar vertebræ with elongated bodies, low neural spines, and the transverse processes placed low down on the bodies. Characters of the limbs not known with certainty.[140]

All the known fossil remains belonging to the animals of this group may be referred, provisionally at least, to the genus Zeuglodon, so named because the first section of a molar tooth examined was taken from the base of the crown, where it was beginning to divide into the two roots, and looked like two single teeth “linked or yoked together.” This name was substituted by Owen for the earlier one Basilosaurus of Harlan, with the consent of that author, on the mammalian nature of the animal being demonstrated.[141] The latter name is, however, still generally retained by American zoologists. The remains have hitherto been found chiefly in the Eocene formations of the States of Alabama, Louisiana, Mississippi, and Arkansas, and have been assigned to several species. A portion of a skull is recorded from the Barton Clay (Eocene) of Hampshire, England.

Suborder Odontoceti, the Delphinoidea, or Toothed Whales.

Calcified teeth always present after birth; generally numerous, but sometimes a very limited number (in a few cases none) are functionally developed. No baleen. Upper surface of the skull more or less asymmetrical. Nasal bones in the form of nodules or flattened plates, applied closely to the frontals, and not forming any part of the roof to the narial passage, which is directed upwards and backwards. Olfactory organ rudimentary or absent. Hinder end of the maxilla expanded and covering the greater part of the orbital plate of the frontal bone. Lachrymal bone either inseparable from the jugal, or, when distinct, very large, and forming part of the roof of the orbit. Tympanic bone not ankylosed with the periotic, which is usually only attached to the rest of the skull by ligament. Rami of mandible nearly straight, much expanded in height posteriorly, with a wide funnel-shaped aperture to the dental canal, and coming in contact in front by a flat surface of variable length, but always constituting a true symphysis. Several of the anterior ribs with well-developed capitular processes, articulating with the bodies of the vertebræ. Sternum almost always composed of several pieces, placed one behind the other, with which several pairs of ribs are always connected by the intervention of well-developed cartilaginous or ossified sternal ribs. External respiratory aperture single, the two nostrils uniting before they reach the surface, usually in the form of a transverse subcrescentic valvular aperture, situated on the top of the head. Manus always pentadactylous, though the first and fifth digits are usually very little developed. No cæcum, except in Platanista.

Family Physeteridæ.

No functional teeth in the upper jaw. Mandibular teeth various, often much reduced in number. Bones of the cranium raised so as to form an elevated prominence or crest behind the nares. Pterygoid bones thick, produced backwards, meeting in the middle line, and not involuted to form the outer wall of the post-palatine air-sinuses, but simply hollowed on their outer side. Anterior facet of periotic bone (Fig. 87) for articulation with the tympanic quite smooth; and the posterior tympanic surface of the former broad, with a median longitudinal ridge. Transverse processes of the arches of the dorsal vertebræ, to which the tubercles of the ribs are attached, ceasing abruptly near the end of the series, and replaced by processes on the body at a much lower level, and not on a line or serially homologous with them, but serially homologous anteriorly with the heads of the ribs, and posteriorly with the transverse processes of the lumbar vertebræ. (In some genera, as Physeter, the two processes, upper and lower on each side, are both present and well developed in the same vertebra in the region of transition. In others, as Ziphius and Berardius, they are not both developed on any single vertebra.) Costal cartilages not ossified.

Subfamily Physeterinæ.—Numerous teeth in the mandible, which are not set in distinct bony alveoli, but in a long groove imperfectly divided by partial septa, and held in place by the strong, fibrous gum surrounding them. No distinct lachrymal bone. Cranium strikingly asymmetrical in the region of the narial apertures, in consequence of the left opening greatly exceeding the right in size.

Physeter.[142]—Upper teeth apparently of uncertain number, rudimentary, and functionless, being embedded in the gum. Lower jaw with from 20 to 25 teeth on each side, stout, conical, recurved, and pointed at the apex until they are worn, without enamel. Upper surface of the cranium concave; its posterior and lateral edges raised into a very high and greatly compressed semicircular crest or wall. Zygomatic processes of jugal bones thick and massive. Rostrum greatly elongated, broad at the base, and gradually tapering to the apex. Upper edge of the mesethmoid forming a roughened irregular projection between the narial apertures, inclining to the left side. Mandible exceedingly long and narrow, the symphysis being more than half the length of the ramus. Vertebræ: C 7, D 11, L 8, C 24; total 50. Atlas free; all the other cervical vertebræ united by their bodies and spines into a single mass. Eleventh pair of ribs rudimentary. Head about one-third the length of the body; very massive, high and truncated, and rather compressed in front; owing its huge size and remarkable form mainly to the accumulation of an oily substance secreted by the lining membranes of great cells surrounding the narial passage and filling the large hollow on the upper surface of the cranium and overlying the rostrum. The single blowhole is longitudinal, slightly sigmoid, and placed at the upper and anterior extremity of the head to the left side of the middle line. The opening of the mouth is on the under side of the head, considerably behind the end of the snout. Pectoral fin short, broad, and obliquely truncated. Dorsal fin a mere low protuberance.

The only representative of this genus is the Cachalot or Sperm Whale (P. macrocephalus, Fig. 83), one of the most colossal of animals, quite equalling, if not exceeding, the Greenland Whale in bulk. The length of the full-grown male is from 55 to 60 feet, but the female is stated not to reach more than half that size. The general colour of the surface is black above and gray below, the colours gradually shading into each other. The Sperm Whale is one of the most widely distributed of animals, being met with usually in herds or “schools” in almost all tropical and subtropical seas, but not occurring, except accidentally, in the Polar regions. Not unfrequently specimens appear on the coasts of the British Isles, but only as solitary stragglers, or as dead carcases, floated northwards by the Gulf Stream. It is remarkable that every one of these of which we have an accurate record has been an old male. The food of this Whale consists mainly of various species of cephalopods (squid and cuttle-fish), but fish of considerable size are also eaten. The substance called “ambergris,” formerly used in medicine and now in perfumery, is a concretion formed in the intestine of this Whale, and is found floating on the surface of the seas it inhabits. Its genuineness is proved by the presence of the horny beaks of the cephalopods on which the Whale feeds.

The oil contained in the great cavity above the skull, when refined, yields “spermaceti,” and the thick covering of blubber which everywhere envelops the body produces the valuable “sperm-oil” of commerce; hence this animal has long been the subject of a regular chase, by which its numbers have been greatly diminished.

Cogia.[143]—Teeth of the upper jaw absent, or reduced to a rudimentary pair in front; in the lower jaw 9 to 12 on each side, rather long, slender, pointed, and curved, with a coating of enamel. Upper surface of the cranium concave, with thick, raised posterior and lateral margins, massive and rounded at their anterior terminations above the orbits. Upper edge of the mesethmoid forming a prominent sinuous ridge, constituting a kind of longitudinal septum to the base of the great supra-cranial cavity. Rostrum not longer than the cranial portion of the skull, broad at the base, and rapidly tapering to the apex. Zygomatic process of the jugal styliform. Mandible with the symphysis less than half the length of the entire ramus. Vertebræ: C 7, D 13 or 14, L and C 30; total 50 or 51. All the cervical vertebræ united by their bodies and arches. External characters not well known, but, judging by the somewhat conflicting accounts of those that have had an opportunity of observing them, the head is about one-sixth of the length of the body, and obtusely pointed in front; the mouth small, and placed far below the apex of the snout; the spiracle crescentic, and placed obliquely on the top of the head anteriorly to the eyes, and to the left of the middle line; the pectoral fins are obtusely falcate; and there is a triangular dorsal fin.

The history of this genus is a good illustration of the difficulties in which the study of the Cetacea has been involved by the superficial manner in which it has been investigated. The first known example, a skull from the Cape of Good Hope in the Paris Museum, was described by De Blainville under the name of Physeter breviceps. This was afterwards with good reason generically separated by Gray. Until within a very few years ago only five other individuals had been met with, each of which had been described under a different specific name (viz. grayi, macleayi, simus, floweri, and potsii), and which are arranged by Gray in two distinct genera. The most careful examination of the description given of these specimens, or of the now numerous osteological remains available, fails to detect any differences beyond those which may be attributed to age or sex, and hence, according to our present knowledge, these six supposed species must all be included under one name, C. breviceps. This animal appears to attain the length of 10 feet when adult, and has been met with at various distant localities in the Southern Ocean, and also off the coast of Madras and in the North Pacific.

Extinct Physeteroids.—Teeth of Physeteroids are of very common occurrence in the Belgian and English Crags, and evidently indicate the former existence of Whales more or less closely allied to the Sperm Whale, but often distinguished by the presence of an enamel-cap on the crowns of the teeth. The generic determination of these teeth is, however, exceedingly difficult, owing to the water-worn condition in which they are frequently found, and also on account of the impossibility of knowing whether small and large teeth may not be referable to different parts of the jaws of the same species or to individuals of different ages. Moreover, in the cases of isolated teeth it is impossible to know how many were contained in the jaws, and therefore to distinguish Physeteroid from Ziphioid teeth. Physeterula is a small form about one-third the dimensions of the Sperm Whale, and distinguished by the length of the mandibular symphysis being only about one-third that of the entire ramus; it is identified by Professor Cope with Cogia. Eucetus (Dinoziphius) is founded on teeth which are regarded as closely resembling those of Physeter, but distinguished by their subcylindrical form and the small size of the aperture of the pulp-cavity. It does not appear, however, to be certain that these teeth are not worn specimens of those described as Scaldicetus. Physetodon, from the Pliocene of Australia, is founded upon the evidence of similar teeth. The teeth from the Belgian Crag described as Scaldicetus are somewhat smaller than those of the Sperm Whale, and are readily characterised by their cap of grooved enamel. Other teeth with enamel-caps have been described as Physodon and Hoplocetus. The genus Balænodon is founded upon a very imperfect large tooth from the English Crag, which is not sufficiently well preserved to admit of exact comparison with the other types.

Subfamily Ziphiinæ.—Teeth of the mandible (at least in existing forms) quite rudimentary and concealed in the gum, except one, or very rarely two, pairs which may be largely developed, especially in the male sex. A distinct lachrymal bone. Externally the mouth is produced into a slender rostrum or beak, from above which the rounded eminence formed by a cushion of fat resting on the cranium in front of the blowhole rises somewhat abruptly. Spiracle or blowhole single, crescentic, median, as in the Delphinidæ. Pectoral fin small, ovate, the five digits all moderately well developed. A small obtusely falcate dorsal fin situated considerably behind the middle of the back. Longitudinal grooves on each side of the skin of the throat, diverging posteriorly, and nearly meeting in front. In external characters and habits the animals of this group closely resemble each other. They appear to be almost exclusively feeders on various species of cephalopods, and occur either singly, in pairs, or in small herds. By their dental and osteological characters they are easily separated into four distinct genera.

Hyperoödon.[144]—A small conical pointed tooth at the apex of each ramus of the mandible, concealed by the gum during life. Skull with the upper ends of the premaxillæ rising suddenly behind the nares to the vertex and expanded laterally, their outer edges curving backwards and their anterior surfaces arching forwards and overhanging the nares; the right larger than the left. Nasal bones lying in the hollow between the upper extremities of the premaxillæ, strongly concave in the middle line and in front; their outer edges, especially on the right side, expanded over the front of the inner border of the maxilla. Very high longitudinal crests on the maxillæ at the base of the rostrum, extending backwards almost to the nares, approaching each other in the middle line above; sometimes so massive that their inner edges come almost in contact. Anteorbital notch distinct. Mesethmoid but slightly ossified. Vertebræ: C 7, D 9, L 10, C 19; total 45. All the cervical vertebræ united. Upper surface of the head in front of the blowhole hole very prominent and rounded, rising abruptly from above the small, distinct snout.

The genus is known typically by H. rostratus (Fig. 84), but an imperfect skull has been made the type of H. planifrons—a species differing considerably in cranial characters from the typical one. The females and young males of the first-named species have the contour of the head of the same general form as in Fig. 84; the premaxillary crests of the cranium being widely separated from one another, and terminating in comparatively sharp edges. In the males, however, as age advances the summits of these crests become gradually expanded and flattened, till they are almost or quite in contact in the middle line. This development of the maxillary crests produces a corresponding elevation and flattening of the front of the head, so that in very old males this aspect presents a flattened disc-like surface rising abruptly from the beak (which thus becomes almost buried) and situated in a plane nearly at right angles to the line of the back.[145] So different, indeed, is the appearance of the skull of an old male from that of a female individual that it was long considered that they belonged to different species—the male form having been described as H. latifrons. The length of an adult male reaches 30 feet, while that of the female does not exceed 24 feet.

The Hyperoödon, sometimes called “Bottlenose,” a name also vaguely given to several species of Dolphin, is a regular inhabitant of the North Atlantic, passing the summer in the Spitzbergen seas and going farther south in winter. It resembles the Sperm Whale in possessing a large store of oil in the upper part of the head, which yields spermaceti when refined; on this account, and also for the sake of the blubber, which supplies an oil almost indistinguishable from sperm-oil, this Whale has been the object of a regular chase in recent years.

The following account of its habits is taken from a paper by Captain D. Gray, published in the Zoological Society’s Proceedings for 1882:—

“These Whales are occasionally met with immediately after leaving the Shetland Isles in March, and north across the ocean until the ice is reached, near the margin of which they are found in the greatest numbers; but they are seldom seen amongst it. Although it is not in their nature to keep in amongst the ice, they like to frequent the open bays for the shelter it gives them from the sea. Sometimes a point of ice overlaps them; it is then only that they are seen going out again towards the ocean. They are also to be met with from the entrance of Hudson’s Straits and up Davis’s Straits, as far as 70° N. lat., and down the east side round Cape Farewell, all round Iceland, north along the Greenland ice to 77° N. lat.; also along the west coast of Spitzbergen, and east to Cherry Island in lat. 72° N. and long. 19° E. Beyond these limits I have never seen them; but doubtless they are to be found as far as the Straits of Belle Isle on the west, and east to Nova Zembla. From the fact that they are not seen in summer farther south than a day’s sail from the ice, it would appear that they migrate south in the autumn, and north again in the spring. They are gregarious in their habits, going in herds of from four to ten. It is rare to see more than the latter number together, although many different herds are frequently in sight at the same time. The adult males very often go by themselves; but young bulls, cows, and calves, with an old male as a leader, are sometimes seen together. They are very unsuspicious, coming close alongside the ship, round about underneath the boats, until their curiosity is satisfied.... They vary in colour from black in the young to light brown in the older animals. The very old turn almost yellow, the beak and front of the head being quite white, with a white band round their necks; all of them are grayish-white on the belly. They can leap many feet out of the water, even having time while in the air to turn round their heads and look about them, taking the water head first, and not falling helplessly into it sideways like the larger whales. The full-grown whale is 30 feet long by 20 feet in circumference, and yields two tons of oil besides two hundredweight of spermaceti.... Their ordinary food consists of a bluish-white cuttle-fish, six inches long by three inches in circumference, and pointed towards the tail.... They evidently have a great depth to go to find them, judging from the length of time that they remain away, and from the long heavy blasts they make on coming to the surface again.”

Periotic bones of Hyperoödon are found in the Red Crag of Suffolk, presenting no character by which they can be specifically distinguished from those of the common existing species.

Ziphius.[146]—A single conical tooth of moderate size on each side of the mandible close to the anterior extremity, and directed forwards and upwards. Skull with the premaxillæ immediately in front of, and at the sides of the nares expanded, hollowed, and with elevated lateral margins, the posterior ends rising to the vertex and curving forwards, the right being considerably more developed than the left; the conjoint nasals forming a strongly pronounced symmetrical eminence at the top of the cranium, projecting forwards over the nares, flat above, most prominent and rounded in the middle line in front, and separated by a notch on each side from the premaxillæ. Anteorbital notch not distinct. Rostrum (seen from above) triangular, gradually tapering from the base to the apex; upper and outer edges of maxillæ at base of rostrum raised into low roughened tuberosities. Mesethmoid cartilage densely ossified in adult age, and coalescing with the surrounding bones of the rostrum. Vertebræ: C 7, D 10, L 10, C 22; total 49. The three anterior cervical vertebræ united, the rest free.

The type of this genus is Z. cavirostris of Cuvier, founded upon an imperfect skull picked up in 1804 on the Mediterranean coast of France, and described and figured in the Ossemens Fossiles under the impression that it was that of an extinct species. Many other individuals have, however, been subsequently met with in various parts of the world, from the Shetland Islands to New Zealand, all referable to the same genus, if not to the same species; although, as is usual in such cases, they have mostly been described under different names, the so-called genera Petrorhynchus and Epiodon being probably referable to the type species.

It is quite probable that some of the Physeteroid teeth from the Crag deposits mentioned on p. 251 may be referable to Ziphius.