Chapter XII: Cetacea--Whales and Dolphins (2)

In the vertebral column the atlas alone is free, the remaining cervicals being fused. There are only eleven dorsal vertebrae, eight lumbars, and twenty-four caudals. The breastbone of this Whale is a roughly-triangular bone made up of three pieces. Four cartilaginous sternal ribs are attached to this bone. The scapula is remarkable for the fact that it is concave on the outer and convex on the inner surface; otherwise it is quite typically Cetacean in form. The shortness of the pectoral limb is shown by the phalangeal formula, which is as follows:--I 1, II 5, III 5, IV 4, V 3. {365}

One of the reasons for the pursuit of the Sperm Whale is the desire to obtain that extremely valuable product ambergris. This substance has long been known; but its true nature was for centuries in dispute. In Dr. Johnson's _Dictionary_ (so recently as the edition of 1818!) ambergris is provided with alternative definitions; it is either the excrement of birds washed off rocks, or honeycombs that have fallen into the sea!

An old writer asserted of ambergris that it was "not the scum or excrement of the whale, but issues out of the root of a tree, which tree, howsoever it stands on the land, alwaies shoots forth its roots towards the sea, seaking the warmth of it, thereby to deliver the fattest gum that coms out of it, which tree otherwise by its copious fatness might be burnt and destroyed." These "explanations" were caused by the fact that ambergris is sometimes found floating in the sea. Ambergris is, of course, a product of the intestinal canal of the Sperm Whale; it seems to be of the nature of cholesterin, and its place of origin was conclusively proved by finding the beaks of cuttle-fish imbedded in it. When first extracted from the alimentary canal it is of greasy feel and consistency; later it hardens, and acquires its characteristic sweet earthy odour. Ambergris is used mainly as a vehicle for scents, and is a costly substance. A piece weighing 130 lbs. was valued at L500. Though now entirely used in connexion with perfumery, it was held by the ancients to be of great value as a specific in certain diseases.

The Sperm Whale is chiefly a tropical animal. Examples that have been cast up on our shores are strayed individuals. It often goes about in herds, which seem to be composed of females. Its food is chiefly cuttle-fishes, and it is said to have a predilection for those colossal cuttle-fishes whose existence has until recently been doubted. Mr. Bullen has sketched a conflict between these two giants of the deep. On the other hand it is said that its large throat, more than big enough to swallow a man (the Whale is credited with being that which swallowed Jonah), does not usually admit fishes larger than Bonitos and Albacores.

The ferocity of the Cachalot has been denied and affirmed. It certainly has great strength, for it can throw itself completely out of the water. Captain Scammon thinks that ships which are mysteriously lost at sea, with no obviously assignable cause, are sometimes the victims of the furious rushes of a bull {366} Sperm Whale. Marco Polo took much the same view, but suggested that the Whale did not deliberately attack the ship, but was deceived by the foam following in its wake into thinking "there is something to eat afloat, and makes a rush forward, whereby it shall often stave in some part of the ship."[249]

Sir W. Flower and many others are of opinion that there is but one species of Cachalot. But many names have been given to supposed other forms. The genus itself has even been divided, and to a set of vertebrae from the south Dr. Gray gave the perfectly superfluous name of _Meganeuron kreffti_. The "High-finned Cachalot" rests mainly upon the suggestions of Sir Robert Sibbald. It is supposed to have a high dorsal fin, and teeth in the upper as well as in the lower jaw. Common though it was asserted by its describer to be, there is not a bone, not a fragment even of a bone, alleged to belong to _Physeter tursio_ in any museum in the world! It seems premature, therefore, to include this mysterious creature in any list of Cetacea, though that was done by no less a naturalist than the late Mr. Thomas Bell. It is this creature round which most of the stories of ferocity congregate. It is held to be the monster from which Perseus delivered Andromeda, and which was about to devour Angelica upon the shore of Brittany. The fact of the matter is, that the Sperm Whale, like so very many other Whales, is world-wide in range; and those naturalists who did not believe in so wide a distribution found themselves obliged, in order to satisfy their own views, to create new species for those of distant localities. Hence the dozen or so of synonyms which refer to what is to be called _Physeter macrocephalus_.

The genus _Kogia_ (sometimes written _Cogia_), the so-called "Pygmy Sperm Whale," is a southern form of much smaller dimensions than its gigantic ally just described. _Kogia_ does not exceed 15 feet or so in length. It differs from _Physeter_ also in the well-marked and falcate dorsal fin, in its generally delphinoid form, in the short snout, and the more normal (for a Whale) shape of the blow-hole, which is crescentic.

There are also a number of osteological characters in which the two Physeterines differ from each other. In _Kogia_ all the cervical vertebrae are ankylosed together; the skull is short, though equally asymmetrical; the ribs are as many as twelve or {367} fourteen; the scapula has not the concave face that it has in _Physeter_. The functional teeth of the lower jaw seem to be reinforced by two on each side of the upper jaw. Moreover, the articulation of the ribs with the vertebrae does not show the very anomalous state of affairs that characterises _Physeter_, where the two heads of a rib may be upon one vertebra.

While there is no doubt as to the generic distinctness of _Kogia_, there is again the same difficulty that is met with throughout the whole of the order in settling into how many species the genus requires dividing.

We can dismiss, as unnecessary, additional generic names (_Euphysetes_, _Callignathus_), but there do appear to be reasons for allowing two species, if the accounts of their osteology are to be depended upon. One of these is _K. breviceps_, with thirteen pairs of ribs, no teeth in the upper jaw, fourteen or fifteen on each side of the lower jaw, vertebral formula C 7, D 13, L 9, Ca 25, and phalangeal formula I 2, II 8, III 8, IV 8, V 7.

The other will then be _K. simus_, with fourteen pairs of ribs, two teeth in the upper jaw, nine in each ramus of the lower jaw, vertebral formula C 7, D 14, L 5, Ca 24, and phalangeal formula I 2, II 5, III 4, IV 4, V 2.

A Californian species has been called _K. floweri_, whose teeth seem to be particularly long and recurved. And the New Zealand _K. pottsi_ has been held to be also a distinct form. There seems to be nothing of special interest to record about the way of life of these Cetaceans, which are but imperfectly known.

SUB-FAM. 2. ZIPHIINAE.--Teeth in the lower jaw not more than two on each side. A distinct lachrymal bone. Stomach with very numerous compartments.

These Whales are all of moderate size, not exceeding 30 feet or so in length. They have a falcate dorsal fin rather near the end of the body; the muzzle is prolonged, hence the name often given to them of "Beaked Whales." The throat is grooved; the blow-hole is single and median, crescentic in form, with the concavity pointing forwards. A character possibly differentiating the Ziphioids from other Whales is the fact that the body ends in a rounded projection between the flukes of the tail. This has at any rate been noted in _Mesoplodon_, _Ziphius_, and _Hyperoodon_. The Ziphioid Whales are by no means common; indeed of _Berardius_ but four or five specimens have ever been {368} met with. Most of them are southern in range, and the vast stretches of desolate coast which occur in these regions of the world account possibly for the rarity of their remains. These Whales have done duty more than once for the "Sea Serpent." Quite recently an alleged sea serpent turned out to be a couple of _Mesoplodon_ lying head to tail! The head in these Whales is small compared to the body. The skull is characterised by the strong maxillary crests, enormously developed in the male _Hyperoodon_. The vertex of the skull too is raised, forming a pronounced prominence behind the aperture of the nares (blow-hole); in many forms the rostrum is made of very dense bone, and is thus relatively abundant in rock strata. The pterygoids meet in the middle line as in the Cachalot. In addition to the few functional teeth in the lower jaw there are more numerous but small teeth in the upper jaw. These are not always to be recognised, as they are not attached to the bone, but merely imbedded in the gums, so that they come away when the skull is prepared.

The genus _Berardius_[250] differs from _Mesoplodon_ by its rather more symmetrical skull, of which the vertex is formed by the nasals. The mesethmoid is only partly ossified. The teeth are two on each side of the mandible, with their apices directed forwards. The vertebral formula is C 7, D 10, L 12, Ca 19.

_B. arnouxi_, from the seas of New Zealand, is the only species of this genus which is well known. It is 30 or 32 feet in length, and is of a velvety black colour, with a greyish belly. Instead of lowing like a cow, this Whale has been described as "bellowing like a bull"! A singular and somewhat inexplicable fact has been stated of this species. The teeth were said to be protrusible, and Sir James Hector stated that the teeth were imbedded "in a tough cartilaginous sac which adheres loosely in the socket of the jaw, and is moved by a series of muscular bundles that elevate or depress it." Sir William Flower justly observed that these statements "accord so little with anything hitherto known in mammalian anatomy that further observations on the subject are extremely desirable." Like other Ziphioids, _Berardius_ feeds mainly, if not entirely, upon cuttle-fish, a prey eminently suited to their almost toothless mouths. It is not known whether _Berardius_ has the {369} Ziphioid grooves upon the throat. Nothing is known of the structure of the internal viscera of this Whale. It appears not to be really limited to the region of New Zealand, as is often stated, for Malm has lately described a skull (_Berardius vegae_) from Bering's Straits.[251]

_Mesoplodon_[252] is a world-wide genus embracing a number of species; on the lowest estimate seven species can be distinguished, and Sir W. Flower would add two more. These are moderate-sized Whales, 15 to 17 feet in length. In the skull the mesethmoid is ossified; the nasals are sunk between the upper ends of the premaxillae. There are but a single pair of teeth in the mandible attached to nearly the middle of its length (whence the generic name). The vertebral formula is C 7, D 9 or 10, L 10 or 11, Ca 19 or 20. The sternum consists of four or five pieces. The amount to which the cervical vertebrae are fused varies; but some are always fused.

The only species which has ever been stranded on the shores of this country is _M. bidens_, an example of which was described many years ago as the "Toothless Whale of Havre"; it was an old animal which had probably lost its teeth. Nevertheless it received the separate generic and specific name of _Aodon dalei_. The animal lived for two days out of the water, and made a sound like the "lowing of a cow." An instance of the rarity of the Whales of this genus is afforded by _M. europaeus_, of which only a single skull is known; this was extracted from a dead body, found floating, about the year 1840. It has never appeared since. _M. layardi_ is remarkable on account of the very large size of its strap-shaped teeth; these curve over the upper jaw in such a way as to prevent the animal from fully opening its jaws. The case is curiously paralleled by the Sabre-toothed Tiger. This species is antarctic in range. From the opposite extremity of the globe comes _M. stejnegeri_, again known by but a single skull. It is singular on account of the large size of the brain case, and is a native of Bering's Straits. _M. hectori_ has its two teeth situated quite at the extremity of the mandible, and in this feature approximates to the genus _Berardius_. It was, indeed, confounded with that genus by one naturalist. {370}

_Ziphius_ is a genus which is also of world-wide range. Here again the number of species is at present merely a matter of opinion. The prevalent impression, however, is that but a single species exists, which will therefore have the name of _Z. cavirostris_. The genus (and for the matter of that the species too) may be thus characterised in comparison with its allies. The mesethmoid is ossified as in _Mesoplodon_, but the nasals joined together form the vertex of the skull. There are two teeth near the symphysis of the mandible, besides the usual small and "functionless" teeth in the upper jaw. The vertebral formula is C 7, D 9 or 10, L 11, Ca 21.

The throat of a _Ziphius_ from New Zealand was described by Messrs. Scott and Parker[253] as having three grooves on each side. Whether this form is the same as von Haast's _Z. novae zelandiae_ is a matter of doubt; but the individual to which his name has been applied was 26 feet long, and had but a single groove on each side. Even in the external characters of many Whales many points require clearing up. Our knowledge of _Ziphius_ dates from the year 1804, when a skull "completely petrified in appearance" was picked up upon the Mediterranean coast of France, and described by the great Cuvier. It was forty years before another specimen was found. In the New Zealand specimen of von Haast already referred to, the body was scored by numerous lacerations. These wounds may have been due to fights among the Whales themselves; the forwardly-situated teeth would be capable of inflicting such wounds. But it has also been stated that the armed suckers of gigantic cuttle-fish are responsible for these scratches.

_Hyperoodon_ is the most easily-distinguishable genus of Ziphioid Whales. Its characters are the following:--The skull has enormously-developed maxillary crests in the adult male; the mesethmoid is not fully ossified. There is but a single tooth to each ramus of the lower jaw, besides, of course, the usual small teeth in the upper jaw. The vertebral formula is C 7, D 9, L 9, Ca 18. The cervicals are fused into one mass, more or fewer being free in other Ziphioids. The sternum consists of three pieces only, the last of which is bifid posteriorly.

The name _Hyperoodon_ was given to this Whale by Colonel Lacepede on account of the rough papillae upon the palate, which {371} were mistaken by that observer for teeth. It is curious that the name is really appropriate in spite of this mistake, though of course it would be so to all the Ziphioids. In more than one feature this genus comes nearest of all the Ziphiinae to _Physeter_. Its enormous maxillary crests are paralleled in that Whale; but in _Hyperoodon_ their great thickness contrasts with the thinness of those of the Cachalot. The correspondence in the attachment of a rib to its vertebra by both heads is noteworthy. It is remarkable that in this particular _Hyperoodon_ is more like _Physeter_ than the supposed nearest ally of the latter--_Kogia_.

Of this genus two species are known. The best known is the common northern _H. rostratum_ (with many aliases); the second species from the southern hemisphere, _H. planifrons_, is only known from a single water- and pebble-worn skull. Its identification, however, depends upon the known accuracy of the late Sir William Flower.

The northern species (_Hyperoodon rostratum_) has often been recorded upon our own coasts; the first record of the stranding of this Whale was in the year 1717. In that year an example was found at Maldon, in Essex. Like the Beluga, _Hyperoodon rostratum_ gets lighter in colour with advancing years. The young are black; the old animals pale brown with some white about them. The under surface, however, is always greyish white. The length of this Whale reaches to at any rate 30 feet. But John Hunter had a specimen which he believed to be 40 feet in length. The specimen, however, consisted only of a skull, so that error might have crept in. It has already been mentioned that the old males have enormous maxillary crests. According to M. Bouvier, who has lately made an exhaustive examination of the anatomy of this Whale,[254] the females occasionally exhibit the same crests, which are thus presumably of the nature of spurs sometimes seen in old females among the Gallinaceous birds. The number of grooves upon the throat is in dispute in this Whale as in _Ziphius_. One pair is the usual allowance; but Kuekenthal found four in some embryos studied by him. Attention has already been called to the voice of Ziphioid Whales. _Hyperoodon_ neither "lows" nor "bellows," but "sobs"! _Hyperoodon rostratum_ is a gregarious Whale, going about in herds, or "gams" as they should technically be termed, of four to ten or even fifteen. This Whale {372} can leap right out of the water, and while in the air can turn its head from side to side, a capability which has not been mentioned in any other Whale. It can also stay under water for an unusually long period. Captain Gray,[255] who has made an accurate study of this species, states that so long a period as two hours is the limit of endurance; this event occurred in the case of a harpooned Whale.

FAM. 2. DELPHINIDAE.--This family, which includes the greater number of Cetacea, may thus be characterised:--Whales of small to moderate size. Teeth as a rule numerous, and present in the upper as well as in the lower jaw. Maxillae without large crests; the pterygoids, often meeting in the middle line, enclose an air space open behind. The anterior (five to eight) ribs are two headed, the posterior with tubercular head only. The sternal ribs are ossified.

The Dolphins and Porpoises, as already stated, embrace the greater number of existing species of Whales. Sir W. Flower and others who have followed him, allow nineteen genera. But as to the exact number of known species there is much uncertainty. That very careful observer, Mr. True, considers[256] that there are fifty which demand recognition. As many as one hundred have received names. The matter is one which is perhaps barely ripe for decision. All the Dolphin tribe are, for Whales, smallish animals. The Killer Whale, _Orca_, is the only genus (or species?) which usually attains to more than moderate bulk. The rather mysterious _Delphinus coronatus_, 36 feet in length, of M. de Freminville, would seem to be a Ziphioid; it was described as having a very pointed beak, and as having the dorsal fin situated near the tail; such characters suggest a _Mesoplodon_.

The genus _Delphinapterus_, the Beluga or White Whale, consists of but a single species, though as usual more than one name has been given to supposed different species. It is characterised as a genus by the following assemblage of structural features:--It has only eight to ten teeth occupying the anterior part of the jaws only. All the cervical vertebrae are free and unjoined. The vertebral formula is C 7, D 11 (or 12), L 9, Ca 23. The pterygoids are wide apart, though they converge as if about to meet at their posterior ends. There is no dorsal fin. The colour is white. {373}

The Beluga is a northern species purely. The reputed form, _D. kingii_, was said to come from Australian seas; but there seems to have been an error in this statement. It is interesting to note that the white colour, so characteristic of the genus and species, is not found in the young, which are blackish. They gradually pale as they advance towards maturity. _Delphinapterus leucas_ reaches a length of 10 feet, and like other Porpoises will ascend rivers in search of food. It is said to be specially addicted to salmon. Among the contents of the stomach have been found quantities of sand. But this habit of swallowing sand or pebbles has been noted in other Whales. Whether it is or is not accidental (taken in with ground-living food), it seems hardly likely that it is used for purposes of ballast! The Beluga has a voice; but the name "Sea Canary" is hardly suitable to it. A specimen of this species, recently described from the shores of Scotland (it is often thrown up upon our coasts), which had got entangled in the stakes of a new net, was regarded by the natives, on account of its white colour, as a ghost. Externally, besides its colour, the Beluga is remarkable for possessing a distinct neck, which is correlated of course with the freedom of the cervical vertebrae, and is also seen in Platanistidae.

The Narwhal (_Monodon_) is closely allied in structure to the last genus. It has the following anatomical characters:--The teeth are reduced to a single "horn" in the upper jaw, which is rudimentary in the female. The neck vertebrae are free. The vertebral formula is C 7, D 11, L 6, Ca 26. The pterygoids are as in _Delphinapterus_, and, as in that genus, there are no hairs upon the face or dorsal fin.

This genus is of course most obviously characterised by the twisted tusk of the male, which is occasionally double. This tusk has given to the only species of the genus, _M. monoceros_, both its generic and specific name. The animal has a spotted colour; but, as in the case of the Beluga, old animals tend to become white. The use of its horn to _Monodon_ has been debated. In the first place it is clearly a secondary sexual character. The males have been observed to cross their horns like rapiers in a fencing match. It may be that they are used in more serious combats. An ingenious suggestion is that the long and strong tusk enables its possessor to break the thick ice and {374} make a breathing hole. A third suggestion is due to Scoresby, who was led to make it from having taken out of the stomach of a Narwhal a large skate. He held that with its tusk the Whale empaled the fish and then swallowed it. The Narwhal is not large, 15 feet or so in length. But Lacepede, who was apt to compile with lack of discrimination, speaks of 60 feet long Narwhals. _Monodon_ is purely Arctic, and but three or four specimens have ever been cast up on our shores.

Of true Porpoises, genus _Phocaena_, there are apparently several species. The genus itself has the following characters:--The teeth are sixteen to twenty-six on each half of each jaw; their crowns are compressed and lobed. The pterygoids do not meet. The dorsal fin has a row of tubercles along its margin.

The Porpoise of our coasts, _P. communis_, is a smallish species 6 to 8 feet in length. There are two to four hairs present in the young; its colour is black, generally lighter on the belly. The first six cervical vertebrae are fused. The ribs vary in number from twelve to fourteen pairs. It is a gregarious Whale, and will ascend rivers; it has been seen for example in the Seine at Paris. The name Porpoise is often written Porkpisce, which of course shows its origin. Very conveniently it was regarded as a fish, and therefore allowed to be eaten in Lent. The celebrated Dr. Caius, a gourmet as well as a physician and the refounder of a college, invented a particular sauce wherewith to dress this royal dish. Some time since Dr. Gray described a Porpoise from Margate as a distinct species (see p. 342) on account of the tubercles, which are now known to be a generic character.

Dr. Burmeister's _P. spinipennis_ seems, however, to be really distinct. It was captured near the mouth of the Rio de la Plata. It is more tuberculated on the fin and back, and has fewer teeth (sixteen as against twenty-six).

Mr. True's _P. dallii_ of the Pacific (where the Common Porpoise also occurs) is characterised chiefly by its very long vertebral column, consisting of ninety-eight vertebrae; there are only sixty-eight in the other species. The Eastern genus _Neomeris_ is placed with _Phocaena_ by Dr. Blanford. It practically only differs by the absence of a dorsal fin. It is only about 4 feet long, and inhabits the seas of India, Cape of Good Hope, and Japan. The one species is called _N. phocaenoides_.

The genus _Globicephalus_ is to be defined thus:--Teeth {375} seven to twelve on each side, confined to anterior end of jaws. Skull raised into a prominence behind the blow-hole; pterygoids large and in contact. Pectoral fin long and falcate; dorsal fin present. No beak. Vertebral formula C 7, D 11, L 11 to 14, Ca 27 to 29. Six pairs of the ribs are two-headed.

The best known species of the genus is the Ca'ing Whale, _G. melas_.[257] This animal reaches a length of 20 feet, and is thus one of the largest of the Delphinidae. It is gregarious and was, even is now, much hunted in the Faeroe Islands. Its sheep-like habits (embodied in one scientific name _deductor_) enable it to be easily driven on shore in herds, which are then harpooned. The foetus of this Whale has a few hairs; the number of phalanges in the two middle digits is very great, as many as eleven to fourteen. _G. scammoni_, _G. brachypterus_, and _G. indicus_ are other reputed species of the genus allowed by True and Blanford.

_Grampus_ is a genus allied to the last. It has no teeth in the upper jaw, and but three to seven in the lower jaw, near the symphysis of the mandible. The pterygoids are in contact. There is no beak, and the pectoral fin is long. There are twelve pairs of ribs, of which six are two-headed. Apparently there is but one species, _G. griseus_, known as "Risso's Dolphin." It is a Mediterranean and Atlantic form, and is not common.

The genus _Orca_ has as characters:--Teeth ten to thirteen, long and strong. Pterygoids not quite meeting. Vertebrae C 7, D 11 to 12, L 10, Ca 23. The first two or three fused. The dorsal fin is long and pointed.

Of this genus there may be more than one species; but the best known is the Killer Whale, _O. gladiator_ (Fig. 180, p. 341), often spoken of as the "Grampus."[258] It is marked with contrasting bands of white or yellow upon a black body-colour. The animal grows to a considerable length, as much as 30 feet. _Orca_ is a powerful and rapacious Whale; and Eschricht has stated that from the stomach of one, thirteen Porpoises and fourteen Seals were extracted. They will also combine to attack larger Whales, and Scammon has related how he witnessed such an onslaught upon a Californian {376} Grey Whale. "Belua truculenta dentibus," observed Olaus Magnus of this Cetacean. The high dorsal fin has been much exaggerated in old drawings; it has been even represented as strong and sharpened at the end, so as to be capable of ripping open the belly of a Whale. The fact that it sometimes lies over a little to one side is responsible for another anecdote: that an example of this Whale was seen to retire with a couple of Seals tucked away under the flippers, another grasped by the dorsal fin, and a fourth in the mouth! "When an Orca pursues a whale," wrote Dr. Frangius, "the latter makes a terrible bellowing like a bull when bitten by a dog." It is probable, according to F. Cuvier, that this Whale is the "Aries marinus" of the ancients, certain bands of white upon the head giving an impression of curved horns. It may also be the "horrible Sea-satyre" of Edmund Spencer.

Allied to _Orca_, but distinguishable from it by some rather minute peculiarities, is _Pseudorca_. It may be thus defined:--Teeth eight to ten, much like those of _Orca_. Dorsal fin rather small, falcate. Vertebral formula C 7, D 10, L 9, Ca 24. Six or all the cervicals united. The curious fact about this Whale, which embraces only a single species, _P. crassidens_, is that it was first known in the fossil condition from remains discovered in the fens of Lincolnshire. An important day for cetologists was that on which a whole herd entered the Baltic and furnished material for a better study of this Whale. It is not, any more than its near ally _Orca_, confined to northern seas; for several examples, at first relegated to a distinct species (_P. meridionalis_), have been obtained from the seas round Tasmania.

_Orcella_ (which has been written _Orcaella_) has fourteen to nineteen small sharp teeth in each half of each jaw. The pterygoids are widely separate. The dorsal fin is small and falcate. The vertebral formula is C 7, D 14, L 14, Ca 26. Seven ribs are two-headed, and five of them reach the sternum.

This genus contains but a single species, _O. brevirostris_, which is both marine and fresh-water in habit; it occurs in the Indian seas, and in the Irrawaddy even as far up as 900 miles from the sea. Some regard the fresh-water individuals as a distinct form, _O. fluminalis_.

_Sagmatias_ is a genus known only from a skull, which is remarkable for the elevation of the premaxillae into a crest; the {377} pterygoids are short, and there are thirty-two teeth in each half of each jaw.

_Feresia_ is known from two skulls which are provided with ten to twelve teeth in each half of each jaw. It is intermediate between _Globicephalus_, _Grampus_, and _Lagenorhynchus_, according to Sir W. Flower.

The genus _Delphinus_ contains the Dolphin, _D. delphis_.[259] The genus may be characterised as follows:--Teeth small and numerous, forty-seven to sixty-five. Vertebral formula C 7, D 14 or 15, L 21 or 22, Ca 30 to 32. The atlas and axis are fused, the rest free. The palatal border of the maxillae is deeply grooved. The fins are falcate; the beak long and distinct.

The Common Dolphin of the Mediterranean shows so many variations of colour, slight differences in the proportions of the bones of the skull, and in the number of the teeth, that it has been divided up into at least seventeen "species." But M. Fischer, who has studied many of these forms, does not admit them, and most students of this group of mammals follow him in the matter. The Dolphin is and has been the most familiar of Cetaceans; in consequence it has accumulated much anecdote of a mythical character. The extreme intelligence and goodwill towards man assigned to this creature by the ancients are possibly due to the anomaly of a creature ostensibly a fish showing many of the characters of higher animals. Its unfishlike intelligence baffled the early observers, who at once endowed it with especially advanced attributes. Hence the stories of Arion and others. The leaping of the Dolphin out of the water is exemplified in many Mediterranean coins and coats of arms; the heraldic dolphin is represented with an arched back as in leaping. The Dolphin reaches a length of some 7 feet, and appears to be world-wide in range. Possibly distinct is _D. longirostris_, characterised, as the name denotes, by the very long beak; it has also more teeth and is a native of Malabar. _D. roseiventris_ again may be a third species of _Delphinus_. It comes from Torres Straits, and has the under parts rosy in colour.

The genus _Prodelphinus_ has, like _Delphinus_, a distinct beak; but it has not the grooved maxillaries. No other character of importance appears to separate it from _Delphinus_. {378}

The genus consists of some eight widely distributed species, which are none of them large Dolphins.

_Lagenorhynchus_ has the following assemblage of characters:--Head with short, not very distinct beak. Dorsal and pectoral fins falcate. Teeth small, twenty-two to forty-five in each half jaw. Vertebrae ranging in number from seventy-three to ninety-two. Pterygoid bones either in contact or separate. There are fifteen or sixteen pairs of ribs, of which six are two-headed. Of this genus Mr. True allows eight species, which have been increased by a ninth since the publication of his "Revision."[260]

Two species of _Lagenorhynchus_ are known from our coasts; the rest are mainly southern in range. The British species are, firstly, _L. albirostris_, a Dolphin of some 9 feet in length. It has a large number of vertebrae, ninety-two in number. _L. albirostris_ is a rare species, the first record of its occurrence on these shores being in 1834. Since that date some eighteen individuals have been shot or stranded on the shores of the British Isles. The second British species, _L. acutus_, differs in colour from the first. As in the last, the upper parts are black and the under parts white; but in _L. acutus_ there is also a stripe on the flanks, brownish in colour. It has fewer vertebrae, not more than eighty-two.

The next genus of Dolphins, _Sotalia_, is characterised by--Teeth tolerably large, twenty-six to thirty-five. The vertebral formula is C 7, D 11 or 12, L 10 to 14, Ca 22. The pterygoids are not in contact in the middle line. It has a distinct beak.

Of this genus there are some six species (the exact number, as in so many other genera, cannot be positively asserted), most of which are fluviatile or estuarine in habit. They are also on the whole characterised by their pale, if not actually white, coloration. _S. sinensis_ of the Amoy is white with pinkish fins. _Sotalia guianensis_ is American as its name denotes. It is figured by van Beneden as of a pale brown colour. It is very abundant in the Bay of Rio de Janeiro, and has the reputation of being a friend of man like some other Dolphins. The natives hold that it will bring to shore the bodies of drowned persons. The most singular species of the genus is that recently described by Professor Kuekenthal as _S. teueszii_.[261] This animal is purely fresh-water, being found in {379} the Camaroon river, where it is extremely rare. The nostrils (blow-hole) are prolonged into a snout-like process, a fact which is of interest in connexion with the assertion that in _Balaenoptera_ the blow-hole is puffed out during spouting. What is temporary in the Rorqual appears to be permanent in the _Sotalia_. More remarkable still, perhaps, is the assertion that it is a vegetable-feeding Dolphin. This is not a mere assertion except that it may not apply universally; for in the stomach of a specimen nothing but vegetable debris was found. But in the stomachs of other Whales (e.g. _Rhachianectes_) vegetable matter has also been found, which may perhaps have been taken in accidentally with the food.

_Steno_ comes near _Sotalia_, and Dr. Blanford has transferred to it (under the one name of _Steno perniger_) the two species, _Sotalia gadamu_ and _Sotalia lentiginosa_. It is, however, to be distinguished from _Sotalia_ by the following characters:--Teeth large and few, twenty to twenty-seven on each side of each jaw, with furrowed surfaces to crowns. Vertebrae C 7, D 12 or 13, L 15, Ca 30 to 32. Pterygoids in contact. There are but two species apparently (not counting Dr. Blanford's).

_Tursiops_ is not a very easily definable genus. These are its chief features:--Teeth large, twenty-two to twenty-six in number in each half of each jaw. Vertebral formula C 7, D 12 or 13, L 16 or 17, Ca 27. Pterygoids in contact. Beak distinct. Some five species are allowed; but it seems to be difficult to differentiate the others from _Tursiops tursio_. This, the best-known form, is quite or nearly world-wide in range, and occurs, though not abundantly, on our own coasts. Mr. True has observed that the eyelids of this Whale, which is largely hunted on the American coast, are as mobile as those of a terrestrial mammal. The name "tursio" is derived from Pliny. Belon would also derive from this word the French vernacular "marsouin." The latter term is sometimes regarded as a corruption of "Meerschwein," but it would seem to be more probably derivable from "marinum suem," from the Latin direct. _T. tursio_ has the back black to lead-colour; the under parts white. In the reputed species, _T. abusalam_, from the Red Sea, the back is a dark sea-green. _T. tursio_ reaches a length of 12 feet, but is more usually smaller.

The genus _Tursio_ must be carefully distinguished from {380} _Tursiops_. It has no dorsal fin, the teeth are small and numerous (forty-four), and the pterygoids are separate. There are two species, _T. borealis_ and _T. peronii_, the former being northern and the latter more widely spread.

The genus _Cephalorhynchus_ has for its chief characters the following:--Teeth twenty-five to thirty-one, small and sharp. Pterygoids widely separated. Dorsal fin not falcate, but triangular or ovate in form. Beak not well marked off from the head. The species of this genus are all southern in range; four are perhaps to be allowed.

FAM. 3. PLATANISTIDAE.--This family of Odontocetes may be distinguished from the Dolphins by the following assemblage of structural features:--Cervical vertebrae all free, and each one of some length (for a Cetacean). Jaws long and narrow, with a considerable length of symphysis. Teeth very numerous.

This very meagre series of differential characters is largely due to _Pontoporia_ on the Platanistid side, and to _Monodon_ and _Delphinapterus_ upon the Delphinid side. Otherwise the family Platanistidae would be extremely distinct. The two last-named genera have separate cervical vertebrae, and in the Beluga at any rate this is expressed externally by a quite distinct neck. Moreover, as Mr. True has pointed out, the pterygoid bones have not the involuted cavity below which characterises other Dolphins; and they have, what other Dolphins have not, an articulation outwards with the roofing bones of the skull. Sir W. Flower described the fact that in Inia (and the same occurs in Pontoporia) the palatines are separated from each other by the intervention of the vomer. In this feature they resemble certain Ziphioids, _Berardius_, _Oulodon_ (= _Mesoplodon_) _grayi_, and _Hyperoodon_. The true Dolphins also appear to show the same intervention of the vomer in a few cases. There is nothing, therefore, distinctive from the Delphinidae in this feature.

The existence of cartilaginous sternal ribs in _Inia_ and _Platanista_ shows affinity between these two genera and the Physeteridae. _Pontoporia_ is Dolphin-like in this particular, as it is also in the mode of articulation of the ribs with the vertebral column. But this last matter has already been dealt with. The principal reason for placing _Pontoporia_ with the other two genera is the close resemblance which its skull bears to that of _Inia_.

The first genus of this family which will be noticed is _Platanista_. {381} The following are its main characters:--Dorsal fin absent. Eyes rudimentary. Pectoral fins large and truncated at the extremity. Teeth, about twenty-nine in each half of each jaw. Scapula with the acromion coinciding with its anterior edge. Skull with enormous maxillary crests, and with the palatines entirely concealed by the pterygoids. The length of the above definition will serve to indicate how anomalous in many particulars is the structure of this "Dolphin."

There is apparently but one species, _P. gangetica_, the "Susu." The Indian vernacular name is derived from the sound that the animal makes when spouting. It is an inhabitant of the Ganges and the Indus, together with their tributaries, and ascends very high up its streams. It is also thought to be purely fluviatile and never to desert the rivers for the sea. _Platanista_ lives chiefly by grubbing in the mud for prawns and fish. Grains of rice have also been found in the stomach, but this would seem to be accidental. The long snout of the Susu has been compared to the long snout of the Gharial, a native of the same region. This Whale grows to a length of over 9 feet, but this length is exceptional. Its anatomy has been elaborately described by Dr. Anderson.[262]

The next genus, _Inia_, is thus to be characterised:--Dorsal fin rudimentary; pectorals large and ovate. Teeth, as many as thirty-two on each side, often with an additional tubercle. Skull without large maxillary crests; palatines not hidden by pterygoids, but divided by vomer. The vertebrae of this genus are few in number, only forty-one in all, which are thus distributed: C 7, D 13, L 3, Ca 18. The peculiarities of the vertebral column are several. In the first place, as has been mentioned in the definition of the family, all the cervicals are separate and individually of some length. Secondly, the axis has a better trace of an odontoid process than in any other Whale except _Platanista_, where it is even more obvious. The lumbar region is remarkable on account of its restriction to three vertebrae. The sternum, by what we must regard as convergence, is somewhat like that of the Whalebone whales. It consists of one piece only, of a roughly-oval form, to which apparently only two pairs of (cartilaginous) sternal ribs are attached. In the fore-limb the proportions between the humerus and the radius are more like {382} those of terrestrial mammals; _i.e._ the humerus is distinctly the longer, the converse usually obtaining among Whales. But _Platanista_ again agrees with _Inia_. The teeth are remarkable for the fact that the hindermost ones of the series have an additional lobe; they are not purely conical as are those of Whales generally.

There is but one species, _Inia geoffrensis_, which inhabits the Amazons, and grows to a length of 8 feet. Its colour variations are rather extraordinary, unless they can be set down to sex, which has been denied. Some individuals are wholly pink; others are black above and pink beneath. This Whale is believed by the Indians to attack a man in the water, and it is added that the _Sotalia_ of the same streams will defend him from these attacks! Naturally, therefore, superstitious reverence attaches to this Dolphin, which is tiresome to the naturalist who wants specimens, as Professor Louis Agassiz found.

In the genus _Pontoporia_[263] the dorsal fin is well developed and falcate. The teeth are very numerous, 200 in all. The ribs articulate as in Dolphins. The skull closely resembles that of Inia, and the scapula is, as in that genus, "normal."

The proper name for _Pontoporia_ is really _Stenodelphis_, which name was first used by Gervais a month or two before Gray, who separated it from the vague _Delphinus_ of its original discoverer, Gervais himself. It has a longer snout than _Inia_, which, being bent towards the extremity in a downward direction, curiously suggests the skull of a Curlew. In details, however, the skull is exceedingly like that of _Inia_. It is nearly symmetrical. The vertebral formula appears to be the following:--C 7, D 10, L 5, Ca 20 = 42, just one over the number of the vertebrae in _Inia_. The sternum is in two pieces. Of the ten pairs of ribs the first three are double-headed. These and the next have sternal moieties joining the sternum, of which the first three are ossified, the last being apparently merely a ligament.

There is a single species of the genus, _P. blainvillii_. This Whale is described by Mr. Lydekker as being of a clear brown colour, harmonising with the waters of the estuary of the Amazons and the La Plata which it inhabits. The same colour characterises _Sotalia pallida_ of those parts of the world, and {383} may be a colour adaptation. But the extant accounts of the colour of this Dolphin vary--quite possibly in accordance with real variations, such as are exhibited by _Inia_ already spoken of. _Pontoporia blainvillii_ is a smallish Dolphin some 4 feet in length.

FOSSIL ODONTOCETES.--Several of the existing genera of Dolphins are also known in a fossil condition, as well as Ziphioid Whales closely related to existing forms. We shall deal here only with a few genera of fossil Odontocetes which depart in their structure from existing forms.

The genus _Physodon_ is Miocene, and has been found in Patagonia. It appears to be most nearly allied to the Physeteridae, but should probably form a distinct family. _Physodon_ was not so large as _Physeter_, the skull measuring only some 10 feet. It thus comes nearer in point of size to _Kogia_, and it is interesting to note that its relatively-shorter snout is also suggestive of the dwarf Cachalot. The general outline of the skull is, however, more like that of _Physeter_, and there is the same deep cavity for the lodgment of spermaceti. The main feature of interest in the skull is the presence of teeth in both jaws, and the fact that two or three are lodged in the premaxillae. This is precisely what is found in the most ancient Whales, the Zeuglodonts.

Extinct Dolphins, apparently referable to the Platanistidae, are the most numerous among the earlier forms of Cetaceans, and it is significant that the earliest known forms of these go back to the Eocene.

The genus _Iniopsis_ of Mr. Lydekker,[264] with one species, _I. caucasica_, comes from rocks which seem to be of that age. The back part of the skull of this animal, the only part of the skull known, has the same squarish excavation of the maxillaries that characterises _Inia_ and _Pontoporia_. Its lower jaw was slender and possessed numerous teeth.

The long snout and jaws of Platanistids, especially exaggerated in _Pontoporia_ among living forms, are constantly found in these Tertiary Platanistids.

_Eurhinodelphis_ had a beak three and a half times the length of the cranium, whereas in _Pontoporia_ the proportions are as 2:1. The teeth too were very numerous.

The genus _Argyrocetus_, from Patagonian Tertiary strata, was an animal about as large as the existing Dolphin. It had the {384} slender rostrum and numerous teeth of the Platanistids and the squared excavations of the maxillaries. _Argyrocetus patagonicus_ possessed also archaic characters, suggesting earlier affinities still. The two condyles of the skull instead of being closely adpressed to the skull stood out in a way more like that met with in terrestrial mammals. The nasal bones instead of being abbreviated rudiments are well developed as in the archaic Zeuglodonts. The cervical vertebrae of this Whale are all perfectly free from each other and individually long. The skull is on the whole bilaterally symmetrical; this again is a feature more pronounced among the Platanistidae than among other Odontocetes. Accompanying these generalised Cetacean characters are some which show that the animal was too specialised to be the direct ancestor of any existing forms. The end of the mandible was upturned and without teeth, its form being quite unique among Cetacea. Other allied forms, such as _Zarrhachis_ and _Priscodelphinus_, showed the same length of the cervical vertebrae.

A very distinct family of extinct Whales is that of the SQUALODONTIDAE. They to some extent bridge over the gap between the existing Odontoceti and the Eocene Archaeoceti (Zeuglodonts).

The skull of these Whales was on the whole Dolphin-like. But they possessed teeth which were distinctly specialised into incisors, canines, and molars. The molars have a coarsely-serrated cutting edge as in the Zeuglodonts, and are also to some extent two-rooted. But they are more numerous, and so far approximate to the conditions which characterise the more typical modern Odontocetes. _Squalodon_ was a long-beaked form, and _Prosqualodon_ had a skull whose proportions are nearer those of _Kogia_.

SUB-ORDER 3. ARCHAEOCETI.

This division of the Whale tribe embraces but a single family, ZEUGLODONTIDAE, of which but a single genus, _Zeuglodon_, can with certainty be discriminated.

_Zeuglodon_ is an Eocene form of large size, with teeth which are limited in number and disposed in three series as incisors, canines, and molars. The molars are double-rooted, a fact which has given to the genus its name. The nasal bones being long {385} instead of rudimentary like those of other Whales, the blow-hole lies more in the middle of the face. The skull, too, is not Whale-like in a number of other points. Thus the premaxillaries take their fair share in the outline of the upper jaw; and, furthermore, bear the incisor teeth. The parietals meet above in a crest and are not excluded from the roof of the skull. The vertebrae of the neck are in no way shortened; neither are they fused together. The ribs are double-headed, and the sternum is made up of several pieces. Some naturalists, particularly Professor D'Arcy Thompson,[265] have assigned a relationship to the Seals to these ancient Cetacea; but others[266] have disputed this view chiefly on the grounds that the characters which appear to be Seal-like are simply characters which are generalised and so far at most not Whale-like. Thus the long neck and the serrated character of the teeth may be accepted as Seal-like on the one hand; but on the other, a simple serrated tooth and a long neck are not by any means features of organisation which we should consider out of the way in an ancient form of Cetacean which probably preyed upon fish. The humerus of _Zeuglodon_, according to Mr. Lydekker, puts out of court any possible near relationship to the Seals. But the matter under dispute can be further studied by reference to the three memoirs quoted below.

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