Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/409

Rh EDENTATA.] MAMMALIA 387 with five well-developed claws, those on the fore feet very long, stout, and subcompressed, the structure of the digits being essentially the same as those ofXe/iurus and Priodon. Nipples two, pectoral. Visceral anatomy closely resembling that of Dasypus, the csecum. being broad, short, and bifid. C. truncatus. The Pichiciago, a small burrowing animal, about 5 inches long, inhabits the sandy plains of the western part of the Argentine Republic, especially the vicinity of Mendoza. Its horny covering is of a pinkish colour, and its silky hair snow white. It is rare, and its habits but little known. A second species, C. reti .sa, from Bolivia, has been described by Burmeister. It is of rather larger size, and has the dorsal shield attached to the skin of the back, as far as its edge, instead of only along the median line. Subfamily Dasypodinse. Fore feet usually with all live digits developed and with nails, though the first and fifth may be suppressed. The first and second long and slender, with the normal number and relative length of phalanges. The others stout, with short broad metaoarpals, and with phalanges greatly reduced in length and generally in number by coalescence. The ungual phalanx of the third very large, that of the others gradually diminishing to the fifth. Dasypus, as now restricted, has the most normal form of manus, but the modifications so markedly developed in all the others (and culminating in Tolypcutcs) are foreshadowed, as it were, in it. Ears wide apart. Maminre one pair, pectoral. Dasypus. Teeth ^ or $, of which the anterior in the upper jaw is usually implanted in the premaxillary bone. The series of teeth extends posteriorly some distance behind the anterior root of the zygoma, almost level with the hinder edge of the palate. They are large, subcylindrical, slightly compressed, diminishing in size towards each end of the series ; the anterior two in the mandible much smaller, and more compressed than the others. Cranial por tion of the skull broad and depressed. Facial portion triangular, broad in front and much depressed. Auditory bulk completely ossified, perforated on the inner side by the carotid canal, and con tinued externally into an elongated bony meatus auditorius, with its aperture directed upwards and backwards. (In all the remain ing genera of Dasypodin-x the tympanic bone is a mere half ring, loosely attached to the cranium.) Mandible with a high ascending ramus, broad transversely-placed condyle, and high slender coronoid process. Vertebra : C 7, D 11-12, L 3, S 8, C 17-18. Head broad and fiat above. Muzzle obtusely pointed. Ears of moderate size or rather small, placed laterally, far apart. Body broad and depressed. Carapace with six or seven movable bands between the scapular and pelvic shields. Tail shorter than the body, tapering, covered with plates forming distinct rings near the base. Fore feet with five toes ; the first much more slender than the others, and with a smaller ungual phalanx and nail ; the second, though the longest, also slender. The third, fourth, and fifth gradually diminishing in length, all armed with very strong, slightly curved, compressed claws, sloping away from an elevated rounded inner border to a sharp, outer, and inferior edge. The hind foot is rather short, with all five toes armed with stout, compressed, slightly curved, obtusely pointed claws, the third the longest, the second nearly equal to it, the fourth the next, the first and fifth shorter and nearly equal. To this genus belongs one of the best-known species of the group, the Six-banded Armadillo or Encoubert (D. scxcinctus) of Brazil and Paraguay. A very similar species, D. villosus, the Hairy Armadillo, replaces it south of the Rio Plata. There are also two very small species, D. vdlcrosus and D. minutus, from the Argentine Republic and North Patagonia. The latter differs from the other three in having no tooth implanted in the premaxillary bone. Xcnurus, Teeth or f, of moderate size and subcylindrical. The most posterior placed a little way behind the anterior root of the zygoma, but far from the hinder margin of the palate. Cranium somewhat elongated, much constricted behind the orbits, and immediately in front of the constriction considerably dilated. Mandible slender ; coronoid process very small and sharp-pointed, sometimes obsolete. Vertebra: C 7, D 12-13, L 5, S 10, C 18. Head broad behind. Ears rather large and rounded, wide apart. Movable bands of carapace 12-13. Tail considerably shorter than the body, and slender, covered with nearly naked skin, with but a few small, scattered, dermal bony plates, chiefly on the under surface and near t*r3 apex. On the fore feet the first and second toes are long and slender, with small claws and the normal number of phalanges ; the other toes have but two phalanges ; the third has an immense falcate claw ; the fourth and fifth similar but smaller claws. The hind feet are comparatively small, with five toes, with small, triangular, blunt nails ; the third longest, the first shortest. The best known species of this genus, the Tatouay or Cabassou, X. unicinctus, is, after Priodon gigas, the largest of the group. It is found, though not abundantly, in Surinam, Brazil, and Paraguay. Others, X. liispidus and lugubris, have been described, but little is as yet known of them. Priodon. Teeth variable in number, and generally differing on the two sides of each jaw, usually from 20 to 25 on each side above and below, so that as many as 100 may be present altogether, but as life advances the anterior teeth fall out, and all traces of their alveoli disappear. The series extends as far back as the hinder edge of the anterior root of the zygoma. They are all very small ; ill the anterior half of each series they are strongly compressed, having flat sides and a straight free edge ; the posterior teeth are more cylindrical, with flat, truncated, free surfaces. Vertebra-: C 7, D 12, L3, S 10, C 23. Head small, elongated, conical. Ears moderate, ovate. Carapace with 12-13 movable bands. Tail nearly equal to the body in length, gradually tapering, closely covered with quadrangular scales, arranged in a quincunx pattern. Fore feet with five toes, formed on the same plan as those ofXenuriifi, but with the claw of the third of still greater size, and that of the others, especially the fifth, proportionately reduced. Hind foot short and rounded, with five very short toes, with short, broad, flat obtuse nails. The only known species, the Great Armadillo (/ . gigas), is by far the largest of existing, members of the family, measuring rather more than 3 feet from the tip of the nose to the root of the tail, the tail being about 20 inches long. It inhabits the forests of Surinam and Brazil. The powerful falcate claws of its fore feet enable it to dig with great facility. Its food consists chiefly of termites and other insects, but it is said to attack and uproot newly- made graves for the purpose of devouring the flesh of the bodies contained in them. Tolypcutcs. Teeth or -, rather large in proportion to the size of the skull, the hinder end of the series reaching nearly to the posterior margin of the palate. Vertebra : C 7, D 11, L 3, S 12..C 13. Ears placed low on the sides of the head, rather large, broadly ovate. Carapace with its scapular and pelvic shields very free at the sides of the body, forming large chambers into which the limbs can be readily withdrawn. Only three movable bands. Tail short, conical, covered with large bony tubercles. The fore feet formed on the same type as the last, but the peculiarities carried out to a still greater extent. The claw of the third toe is very long and falcate, the first and fifth greatly reduced and sometimes want ing. On the hind foot the three middle toes have broad, flat, subequal nails, forming together a kind of tripartite hoof ; the first and fifth much shorter and with more compressed nails. The Armadillos of this genus have the power of rolling them selves up into a perfect ball, the shield on the top of the head and the tuberculated dorsal surface of the tail exactly fitting into and filling up the apertures left by the notches at either end of the carapace. This appears to be their usual means of defence when frightened or surprised, as they do not burrow like the other species. They run very quickly, with a very peculiar gait, only the tips of the claws of the fore feet touching the ground. Three species are described: T. tricinctus, the Apar ; T. conurus, the Matico ; and T. muriei. Subfamily Tatusiinee. This contains but one genus, Tatusia. Teeth or Z, very small, subcylindrical. The first and second sub- compressed, the last considerably smaller than the others. They pre sent the remarkable peculiarity (unique among Edentates, so far as FIG. SS.GJt/ptodon cJavipes (Pleistocene, South America). From Owen. is yet known) of all being, with the exception of the last, preceded by two-rooted milk teeth, which are not changed until the animal has nearly attained its full size. Vertebrae: C7, D9-11, L 5, S8, C 20-27. Head narrow, with a long, .. narrow, subcylindrical., obliquely-truncated snout. Ears rather large, ovate, and erect, placed close together on the occiput. Carapace with seven to nine distinct movable bands. Body generally elongated and narrow. Tail mode rate or long, gradually tapering; its dermal plates forming very dis tinct rings for the greater part of its length. Fore feet with fou visible toes, and a concealed clawless rudiment of the fifth, all long, slightly curved, and very slender, the third and fourth