Page:EB1911 - Volume 05.djvu/383

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370
CARNIVORA


Asia and Africa, and while many of the species, like the Egyptian H. ichneumon and the ordinary Indian mongoose, H. mungo, are pepper-and-salt coloured, the large African H. albicauda has the terminal two-thirds of the tail clothed with long white hairs (see Ichneumon).

The following distinct African and Malagasy generic representatives of the subfamily are recognized, viz. Helogale, with 3/3 premolars, and containing the small South African H. parvula and a variety of the same. Bdeogale crassicauda and two allied tropical African species differ from Herpestes in having only four toes on each foot. The orbit is nearly complete, and the tail of moderate length and rather bushy. In Cynictis, which has the orbit completely closed, there are five front and four hind toes; and the skull is shorter and broader than in Herpestes, rather contracted behind the orbits, the face short, and the anterior chamber of the auditory bulla very large. The front claws are elongated. Includes only C. penicillata from South Africa.

All the foregoing herpestines have the nose short, with its under surface flat, bald, and with a median longitudinal groove. The remaining forms have the nose more or less produced, with its under side convex, and a space between the nostrils and the upper lip covered with closely pressed hairs, and without any median groove. The South African Rhynchogale muelleri, a reddish animal with five toes to each foot and 4/4 (abnormally 5/5) premolars, alone represents the first genus. The cusimanses (Crossarchus), which differ by having only 3/3 premolars, and thus a total of 36 teeth, include, on the other hand, several species. The muzzle is elongated, the claws on the fore-feet are long and curved, the first front toe is very short; the under surface of the metatarsus naked; and the tail shorter than the body, tapering. Fur harsh. Includes C. obscurus, the cusimanse, a small burrowing animal from West Africa, of uniform dark-brown colour, C. fasciatus, C. zebra, C. gambianus and others. Lastly, we have Suricata, a more distinct genus than any of the above. The dental formula is as in the last, but the teeth of the molar series are remarkably short in the antero-posterior direction, corresponding with the shortness of the skull generally. Orbits complete behind. Vertebrae: C. 7, D. 15, L. 6, S. 3, Ca. 20. Though the head is short and broad, the nose is pointed and rather produced and movable, while the ears are very short. Body shorter and limbs longer than in Herpestes. Toes 4-4. Claws on fore-feet very long and narrow, arched, pointed and subequal. Hind-feet with shorter claws, soles hairy. Tail rather shorter than the body. One species only is known, the meerkat or suricate, S. tetradactyla, a small grey-brown animal, with dark transverse stripes on the hinder part of the back, from South Africa.

The names Galidictis, Galidia and Hemigalidia indicate three generic modifications of the Herpestinae, all inhabitants of Madagascar. The best-known, Galidia elegans, is a lively squirrel-like little animal with soft fur and a long bushy tail, which climbs and jumps with agility. It is of a chestnut-brown colour, the tail being ringed with darker brown. Galidictis vittata and G. striata chiefly differ from the ichneumons in their coloration, being grey with parallel longitudinal stripes of dark brown.

Considerable diversity of opinion prevails with regard to the serial position of the aard-wolf, or maned jackal (Proteles cristatus), of southern and eastern Africa, some authorities making it the representative of a family by itself, others referring it to the Hyaenidae, while others again regard it as a modified member of the Viverridae. After all, the distinction either way cannot be very great, since the two families just named are intimately connected by marks of the extinct Ictitherium, With the Viverridae it agrees in having the auditory bulla divided, while in the number of dorsal vertebrae it is hyena-like. The cheek-teeth are small, far apart, and almost rudimentary in character (see fig. 4), and the canines long and rather slender. The dental formula is i3/3, c1/1, p.m. 4/3 or 4; total 30 or 32. Vertebrae: C. 7, D. 15, L. 5, S. 2, Ca. 24. The fore-feet with five toes; the first, though short, with a distinct claw. The hind-feet with four subequal toes; all, like those of the fore-foot, furnished with strong, blunt, non-retractile claws (see Aard-Wolf).

The hyenas or hyaenas (Hyaenidae) differ from the preceding family (Viverridae) in the absence of a distinct vertical partition between the two halves of the auditory bulla; and are further characterized by the absence of an alisphenoid canal, the reduction of the molars to 1/1, and the presence of 15 dorsal vertebrae. The dental formula in the existing forms Hyena tribe. (to which alone all these remarks apply) is i3/3, c1/1. p4/3 m1/1; total 34; the teeth, especially the canines and premolars, being very large, strong and conical. Upper sectorial with a large, distinctly trilobed blade and a moderately developed inner lobe placed at the anterior extremity of the blade. Molar very small, and placed transversely close to the hinder edge of the last, as in the Felidae. Lower sectorial consisting of little more than the bilobed blade. Zygomatic arches of skull very wide and strong; and sagittal crest high, giving attachment to very powerful biting muscles. Orbits incomplete behind. Vertebrae: C. 7, D. 15, L. 5, S. 4, Ca. 19. Limbs rather long, especially the anterior pair, digitigrade, four subequal toes on each, with stout non-retractile claws, the first toes being represented by rudimentary metacarpal and metatarsal bones. Tail rather short. A large post-anal median glandular pouch, into which the largely developed anal scent glands pour their secretion.

EB1911 Carnivora Fig. 4 - Skull and Dentition of Aard-Wolf.jpg

Fig. 4.—Skull and Dentition of Aard-Wolf (Proteles cristatus.)

The three well-characterized species of Hyaena are divisible into two sections, to which some zoologists assign generic rank. In the typical species the upper molar is moderately developed and three-rooted; and an inner tubercle and heel more or less developed on the lower molar. Ears large and pointed. Hair long, forming a mane on the back and shoulders. Represented firstly by H. striata, the striped hyena of northern and eastern Africa and southern Asia; and H. brunnea of South Africa, in some respects intermediate between this and the next section. In the second section, forming the subgenus Crocuta, the upper molar is extremely small, two- or one-rooted, often deciduous; the lower molar without trace of inner tubercle, and with an extremely small heel. Ears moderate, rounded. Hair not elongated to form a mane. The spotted hyena, Hyaena (Crocuta) crocuta, of which, like the striped species, there are several local races, represents this group, and ranges all over Africa south of the Sahara. In dental characters the first section inclines more to the Viverridae, the second to the Felidae; or the second may be considered as the more specialized form, as it certainly is in its visceral anatomy, especially in that of the reproductive organs of the female. (See Hyena.)

(B) Arctoidea.—So far as the auditory region of the skull is concerned, the existing representatives of the dog tribe or Canidae are to a great extent intermediate between the cat and civet group (Aeluroidea) on the one hand, and the typical representatives of the bear and weasel group on the other. They were consequently at one time classed in an intermediate group—the Cynoidea; but fossil forms show such a complete transition from dogs to bears as to demonstrate the artificial character of such a division. Consequently, the dogs are included in the bear-group. In this wider sense the Arctoidea will be characterized by the tympanic bone being disk-shaped and forming the whole of the outer wall of the tympanic cavity; the large size of the external auditory meatus or tube; and the large and branching maxillo-turbinal bone, which cuts off the naso-turbinal and two adjacent bones from the anterior nasal chamber. The tympanic bulla has no internal partition. There is a large carotid canal. Cowper’s glands are lacking; and there is a large penial bone.

From all the other members of the group the Canidae are broadly distinguished (in the case of existing forms) by the large and well-developed tympanic bulla, with which the paroccipital process is in contact. An alisphenoid canal is present. The feet are digitigrade, usually with five (in one instance four) front and always four hind-toes. The molars—generally Dog tribe. 2/3—have tall cusps, and the sectorials are large and powerful (figs. 1 and 2). The intestine has both a duodeno-jejunal flexure and a caecum. A prostate gland is present; but there are no glands in the vasa deferentia; the penial bone is grooved; and anal glands are generally developed. The distribution of the family is cosmopolitan. The normal dentition is i3/3, c1/1, p4/4, m2/3; total 42; thus differing from the typical series only by the loss of the last pair of upper molars (present in certain extinct forms). In the characters of the teeth the group is the most primitive of all Carnivora. Typically the upper secterial (fig. 1, II) consists of a stout blade, of which the anterior cusp is almost obsolete, the middle cusp large, conical and pointed backwards, and the posterior cusp in the form of a compressed ridge; the inner lobe is very small, and placed at the fore part of the tooth. The first molar is more than half the antero-posterior length of the sectorial, and considerably wider than long; its crown consists of two prominent conical cusps, of which the anterior is the larger, and a low, broad inward prolongation, supporting two more or less distinct cusps and a raised inner border. The second molar resembles the first in general form, but is considerably smaller. The lower sectorial (fig. 2, II) is a large tooth, with a strong compressed bilobed blade, the hinder lobe being considerably the larger and more pointed, a small but distinct inner tubercle