Page:EB1911 - Volume 05.djvu/387

 larger than the sectorial, and in the more typical genera is much longer than broad.

In the North American skunks of the genus Mephitis the dentition is i. $3⁄3$, c. $1⁄1$, p. $3⁄3$, m. $1⁄2$; total 34. Upper molar larger than the sectorial, subquadrate, rather broader than long; lower sectorial with heel less than half the length of the whole tooth. Bony palate terminating posteriorly opposite the hinder border of the last molar. Facial portion of skull short and somewhat truncated in front. Vertebrae: C. 7, D. 16, L. 6, S. 2, Ca. 21. Head small. Body elongated. Limbs moderate, subplantigrade. Ears short and rounded. Tail long, abundantly clothed with long fine hair. Anal glands largely developed; their secretion, which can be discharged at the will of the animal, has an intolerably offensive odour and has rendered skunks proverbial. The South American species, which have only two upper premolars, and differ in some other characters, are generically separated under the name of Conepatus; while the small North American arboreal skunks are distinguished as Spilogale (see ).

Passing on to the more typical members of the badger group, we have first the genus Arctonyx, with the dentition i. $3⁄3$, c. $1⁄1$, p. $4⁄4$, m. $1⁄2$; total 38. The incisor line is curved, the outer teeth being placed posteriorly to the others: lower incisors inclined

forwards. First premolars often rudimentary or absent; upper molar much larger than the sectorial, longer in the antero-posterior direction than broad; lower sectorial with a very large, low, tuberculated heel. Skull elongated and depressed; face long, narrow and concave above; bony palate extending as far backwards as the level of the glenoid fossa; and palatal bones dilated. Suborbital foramina very large. Vertebrae: C. 7, D. 16, L. 4, S. 4, Ca. 20. Snout long, naked, mobile and truncated, with large terminal nostrils, much like those of a pig. Eyes small; ears very small and rounded. Body compressed, rather than depressed. Limbs of moderate length, and partially digitigrade in walking. Tail moderate, tapering. A full soft under-fur, with longer bristly hairs interspersed. The longest-known species is A. collaris, the bhalu-soor (bear-pig) or bali-soor (sand-pig) of the natives of the mountains of north-eastern India, Burma and Borneo. It is rather larger than the badger, higher on its legs, and very pig-like in general aspect, of a light grey colour, with flesh-coloured snout and feet; nocturnal and omnivorous. Other species or local varieties have been described from north China and Burma.

In the genus Mydaus the dentition is as the last, but the cusps of the teeth are more acutely pointed. Skull elongated, face narrow and produced. Suborbital foramen small, and the palate, as in all the succeeding genera of this group, produced backwards about midway between the last molar and the glenoid fossa. Vertebrae: C. 7, D. 14-15, L. 6-5, S. 3, Ca. 12. Head pointed in front; snout produced, mobile, obliquely truncated, the nostrils being inferior. Limbs rather short and stout. Tail extremely short, but clothed with rather long bushy hair. Anal glands largely developed, and emitting an odour like that of the skunks. One species, M. meliceps, the teledu, a small burrowing animal from the mountains of Java, at an elevation of 7000 or more ft. above the sea-level; and a second (M. marchei) from the Philippines.

In the true badger of the genus Meles the dentition is i. $3⁄3$, c. $1⁄1$, p. $4⁄4$, m. $1⁄2$; total 38. The first premolar in both jaws is extremely minute and often deciduous; while the upper molar is much larger than the sectorial, subquadrate, and as broad as long. Lower sectorial with a broad, low, tuberculated heel, more than half the length of the whole tooth. The postglenoid process of the skull so strongly developed, and the glenoid fossa so deep, that the condyle of the lower jaw is firmly held in place after the soft parts are removed. Vertebrae: C. 7, D. 15, L. 5, S, 3, Ca. 18. Muzzle pointed. Ears very short. Body stout, broad. Limbs short, strong, subplantigrade. Tail short. Typified by the common badger (M. taxus or M. meles) of Europe and northern Asia, still found in many parts of England, where it lives in woods, is nocturnal, burrowing and very omnivorous, feeding on mice, reptiles, insects, fruit, acorns and roots. Other nearly allied species, M. leucurus and M. chinensis, are found in continental Asia, and M. anakuma in Japan.

In the nearly-allied genus Taxidea the dental formula is as in Meles, except that the rudimentary anterior premolars appear to be always wanting in the upper jaw. The upper sectorial is much larger in proportion to the other teeth; and the upper molar about the same size as the sectorial, triangular, with the apex turned backwards. Heel of lower sectorial less than half the length of the tooth. Skull very wide in the occipital region; the lambdoidal crest greatly developed, and the sagittal but slightly, contrary to what obtains in Meles. Vertebrae: C. 7. D. 15. L. 5, S. 3, Ca. (?). Body stoutly built and depressed. Tail short. The animals of this genus are peculiar to North America, where they represent the badgers of the Old World, resembling them much in appearance and habits. T. americana is the common American badger of the United States, T. berlandieri, the Mexican badger, being a local variety.

The third and last subfamily is that of the otters, or Lutrinae, in which the feet (with the exception of the hind pair in the sea-otter) are short and rounded, with the toes webbed, and the claws small, curved and blunt. The head is broad and

much depressed. The upper posterior cheek-teeth are large and quadrate. The kidneys are conglomerate. Habits aquatic.

In the true otter of the genus Lutra the dentition is i. $3⁄3$, c. $1⁄1$, p. $4⁄3$, m. $1⁄2$; total 36. Upper sectorial with a trenchant tricusped blade, and a very large inner lobe, hollowed on the free surface, with a raised sharp edge, extending along two-thirds or more of the length of the blade. Upper molar large, with a quadricuspidate crown, broader than long. Skull broad and depressed, contracted immediately behind the orbits; with the facial portion very short and the brain-case large. Vertebrae: C. 7, D. 14-15, L. 6-5, S. 3, Ca. 20-26. Body very long. Ears short and rounded. Limbs short. Feet completely webbed, with well-developed claws on all the toes. Tail long, thick at the base and tapering, rather depressed. Fur short and close.

Otters are more or less aquatic, living on the margins of rivers, lakes, and in some cases the sea; are expert divers and swimmers, and feed chiefly on fish. They have an extensive geographical range, and so much resemble each other in outward appearance, especially in the nearly uniform brown colouring, that in some cases the species are by no means well-defined. The Brazilian otter (L. brasiliensis) is a very large species from Brazil, Demerara and Surinam, with a prominent ridge along each lateral margin of the tail. In two small species the feet are only slightly webbed; claws exceedingly small or altogether wanting on some of the toes; the first upper premolar very small, sometimes wanting; and the molars very broad and massive. The species in question are L. inunguis of South Africa, and L. leptonyx or cinerea of India, Java and Sumatra, and have been separated as a distinct genus, Aonyx.

The sea-otter, Latax (or Enhydra) lutra, with a dentition of i. $3⁄2$, c. $1⁄1$, p. $3⁄3$, m. $1⁄2$, total 32, differs from other Carnivora in having but two incisors on each side of the lower jaw, the one corresponding to the first (very small in the true otters) being absent. Though the molar teeth generally resemble those of Lutra in their proportions, they differ in the exceeding roundness and massiveness of their crowns and bluntness of their cusps. Feet webbed; fore-feet short, with five subequal toes, with short compressed claws; hind-feet very large, depressed and fin-like, their phalanges flattened as in seals. The fifth toe the longest and stoutest, the rest gradually diminishing in size to the first, all with moderate claws. Tail moderate, cylindrical (see ).

The second suborder is formed by the seals, walruses and eared seals, which differ from the rest of the Carnivora mainly in the limbs being modified for aquatic progression; the two upper segments being very short and partially enveloped in the general integument of the body, while the third, especially in the hind extremities, is elongated, expanded and webbed. There are always five well-developed digits on each limb. In the hind-limb the two marginal digits (first and fifth) are stouter and generally larger than the others. The teeth also differ from those of the more typical Carnivora. The incisors are always fewer than $3⁄3$. The chsek series consists generally of four premolars and one molar of uniform characters, with never more than two roots, and with conical, more or less compressed, pointed crowns, which may have accessory cusps, placed before or behind the principal one, but are never broad and tuberculated. The milk-teeth are small, simple and shed or absorbed at an early age, usually either before or within a few days after birth. The brain is relatively large, the cerebral hemispheres broad in proportion to their length, and with numerous and complex convolutions. There is a very short caecum; the kidneys are divided into numerous distinct lobules. There are no Cowper’s glands. Teats two or four, abdominal. No clavicles. Tail always short. Eyes large and exposed, with flat cornea. The nostrils close by the elasticity of their walls, and are opened at will by muscular action.

The members of this group are aquatic, spending the greater part of their time in the water, swimming and diving with great facility, feeding mainly on fish, crustaceans and other marine animals, and progressing on land with difficulty, but always coming on shore for the purpose of bringing forth their young. They are generally marine, but occasionally ascend large rivers, and some inhabit inland seas and lakes, as the Caspian and Baikal. Though not numerous in species, they are widely distributed over the world, but occur most abundantly on the coasts of lands situated in cold and temperate zones.

As mentioned in the article, the true seals (Phocidae), together with the walruses, may be directly descended from the primitive Creodont Carnivora. The eared seals, on the other hand, show signs of affinity with the bears; but as they are of earlier geological age than the latter, they cannot be derived from that group.