Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/463

Rh CARNIVORA.] M A M MALTA 439 large ears and cotTesponJing large auditory bullee, have been separ ated under the above name. Lycaon. This resembles in most of its characters the Dogs of the Lupine series, but the teeth are rather more massive and rounded, the skull shorter and broader, and it has but four toes on each limb, as in Hyaena. The one species, L. pidus, the Cape Hunting Dog (fig. 120) from south and east Africa, is very distinct exter- FIG. 120. Cape Hunting Dog (Lycaon piclus). nally from all the other Canidae. It is nearly as large as a mastiff, with large, broadly ovate erect ears, and singularly coloured, being not only variable in different individuals, but unsymmetrically marked with large spots of white, yellow, and black. It presents some curious superficial resemblances to Hymna crocuta, perhaps a case of mimetic analogy. It hunts its prey in large packs. Otocyon. Dentition: if, c }, p, m 3 -2p=!i^. total 46 or 48. The molar teeth are thus in excess of any other known heter- odont mammal. They have the same general characters as in Canis, with very pointed cusps. The lower sectorial shows little of its typical characters, having five cusps on the surface ; these can, however, be identified as the inner tubercle, the two greatly reduced and obliquely placed lobes of the blade, and two cusps on the heel. The skull generally resembles that of the smaller Foxes, particularly the Fennecs. The auditory bullse are very large. The hinder edge of the mandible has a very peculiar form, owing to the great development of an expanded, compressed, and somewhat inverted subangular process. Vertebrae: C 7, D 13, L 7, S 3, C 22. Ears very large. Limbs rather long. Toes 5-4. One species, 0. megalotis, from South Africa, rather smaller than a common Fox. Professor Huxley looks upon this as the least differentiated or most primitive existing form of Canis, regarding the presence of the four molar teeth as a survival of a condition of the dentition exhibited by the common ancestors of the existing Canidse and the existing carnivorous Marsupials. There is, however, at present no paljeontological proof of this, as none of the numerous fossil forms of CanidsR yet discovered have more than the normal number of molars. One of the best known of these is Amphicyon, from the Miocene strata of Europe and America, formerly supposed to have affinities with the Bears, having five toes on each foot, and being possibly plantigrade, but, as the structure of the skull and teeth clearly show, only a generalized Dog, in which the true molars are fully developed. Another genus, Cynodidis, of which many modi fications have been described by Filhol from the south of France, approaches the Vivcrridse, and may be a common ancestor of the Cynoid and jEluroid Carnivora. Section ARCTOIDEA. The section Arctoidea includes a considerable number of forms which agree in the essential characteristics of the structures of the base of the cranium and reproductive organs, and in the absence of a cacum to the intestinal canal. They have no Cowper s glands, and have a rudimentary prostate and a large cylindrical penial bone. All the mernbers of this group have five completely developed toes on each foot. Family True molars (or | in Mellivora). No alisphenoid canal. A large group widely diffused, especially in the northern temperate regions of the earth. The different genera are very difficult to arrange in any natural order. They are rather artificially divided, chiefly according to the characters of their feet and claws, into the Otter-like (Lutrme), Badger-like (Meline), and Weasel-like (Muste- line) forms. Subfamily Lutrinee. Feet short, rounded (except the hind feet of Enhydra}. Toes webbed. Claws small, curved, blunt. Head broad and much depressed. Upper posterior molars large and quadrate. Kidneys conglomerate. Habits aquatic. Lutra. Dentition: i f, c |, p, m $; 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, and extending along two-thirds or more of the length of the blade. True molar large, with a quadricuspidate crown, broader than long. Skull broad and depressed, contracted immediately behind the orbits. Facial portion very short; brain case large. Vertebrae- C 7, D 14-15, L 6-5, S3, C 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. The Otters are all 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 a very extensive geographical range, and so much resemble each other in outward appearance, especially in the nearly uniform brown colouring, that the species are by no means well-defined. See OTTER. L. sandbachii, a very large species from Demerara and Surinam, with a prominent ridge along each lateral margin of the tail, con stitutes the genus Pleronura of Gray. Aonyx. Feet only slightly webbed ; claws exceedingly small or altogether wanting on some of the toes. First upper premolar very small, sometimes wanting. True molars very broad and massive, presenting an approach tt&amp;gt; the form of the next genus. A. inunguis, South Africa ; A. leptonyx, Java, Sumatra. Enhydriodon. E. sivalensis is a large extinct Otter-like animal described by Dr Falconer from the Pliocene strata of the Sub- himalayan mountains. Enhydra. Dentition : i f, c , p f , TO $ ; total 32. Differs from all other known 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 constantly absent. Though the molur teeth generally resemble those of Lutra in their proportions, they differ very much in the exceeding roundness and massiveness of their crowns and bluritness of their cusps. Feet webbed. Fore feet short, with five subequal toes, with short compressed claws. Hind feet very large, depressed, and fin-like. The phalanges flattened as in the Seals. The fifth toe the longest and stoutest, the rest gradually diminishing in size to the first, all with mode rate claws. Tail moderate, cylindrical. One species, E. lutris, the Sea-Otter. It is larger than any of the true Otters, and is found only on the coasts and islands of the North Pacific, where it was formerly very abundant, but is gradu ally becoming more and more rare, on account of the numbers killed annually for their valuable fur. It is said to live on molluscs and crabs as well as fish, and the massive mill-like struc ture of the grinding teeth, so unlike that of all the known purely piscivorous mammals, would seem to indicate some such diet. Subfamily Melinse. Feet elongated. Toes straight. Claws non-retractile, slightly curved, subcompressed, blunt ; those of the fore foot especially large. Upper posterior molar variable. Kidneys simple. Habits mostly terrestrial and fossorial, Mephitis. Dentition: i f, c $, p 2 ~? , m $ ; total 32-34. 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 tooth. Facial portion of skull short and somewhat truncated in front. Vertebrae : C 7, D16, L6, S2, C21. Head small. Body elongated. Limbs moderate, subplantigrade. Ears short and rounded. Tail long, abundantly clothed with very long fine hair. Anal glands largely developed ; their secretion, which can be discharged at the will of the animal, has an intolerably offensive odour, which circumstance has ren dered the Skunks, as they are commonly called, proverbial. They are strictly nocturnal animals, terrestrial and burrowing, feeding chiefly on small mammals, birds, reptiles, insects, worms, roots, and berries. All the known species have a prevalent black colour, varied by white stripes or spots on the upper part. They generally carry the body much arched, and the tail erect, the long loose hair of which waves like a plume over the back. There are many species, all inhabitants of the American continent, over which they have an extensive range. See SKUNK. The South -American species, which have only two upper premolars, and differ in some other characters, have been genetically separated under the name of Conepatus. Arctonyx. Dentition : i f, c {, p f , m % ; total 38. Incisor line curved, the outer teeth being placed posteriorly to the others. Lower incisors proclivous. First premolars often rudimentary or absent. Upper molar much larger than the sectorial, longer in the