L 3

l 3, s 10, ca 23. head small, elongated, conical. ears moderate, ovate. armour 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 of _tatoua_, but with the claw of the third of still greater size, and that of the others, especially the fifth, proportionally reduced. hind-foot short and rounded, with five very short toes, and short, broad, flat obtuse nails. the giant armadillo is by far the largest existing member of the family, measuring rather more than 3 ft. from the tip of the nose to the root of the tail, the tail being about 20 in. long. it inhabits the forest of surinam and brazil. the powerful claws of its fore-feet enable it to dig with great facility; and its food consists chiefly of termites and other insects, although it is said to attack and uproot newly-made graves for the purpose of devouring the flesh of the bodies contained in them. the apar (_tolypeutes tricinctus_) typifies a genus in which the teeth are 9/9 or 8/9, and are rather large in proportion to the size of the skull, with the hinder end of the series reaching nearly to the posterior margin of the palate. vertebrae: c 7, d 11, l 3, s 12, ca 13. ears placed low on the sides of the head, rather large, broadly ovate. armour 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and pelvic shields very free at the sides of the body, forming large chambers into which the limbs can be readily withdrawn, and only three movable bands. tail short, conical, covered with large bony tubercles. the fore-feet formed on the same type as in the last genus, but the peculiarities carried to a still greater extent. the claw of the third toe is very long, while those of the first and fifth are greatly reduced and sometimes wanting. 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, with more compressed nails. the armadillos of this genus have the power of rolling themselves up into a 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 body-armour. 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. in addition to the apar, there are the argentine and bolivian _t. conurus_, and _t. muriei_ from argentina or patagonia. the last group of existing armadillos forms the genus _tatusia_ and the subfamily _tatusiinae_; the subfamily rank being based on the fact that of the seven or eight pairs of small subcylindrical teeth, all but the last, which is considerably smaller than the rest, are preceded by milk-teeth not changed until the animal has nearly attained full size. vertebrae: c 7, d 9-11, l 5, s 8, ca 20-27. head narrow, with a long, narrow, subcylindrical obliquely truncated snout. ears rather large, ovate and erect, placed close together on the occiput. armour with seven to nine distinct movable bands. body generally elongated and narrow. tail moderate, or long, gradually tapering; its plates forming distinct rings for the greater part of its length. fore-feet with four visible toes, and a concealed clawless rudiment of the fifth; the claws long, slightly curved, and slender, the third and fourth subequal and alike, the first and fourth much shorter. hind-feet with five toes, armed with strong, slightly curved, conical, obtusely pointed nails, and the third longest, then the second and fourth, and the first and fifth much shorter than the others. this genus differs from all the other armadillos in having a pair of inguinal teats in addition to the usual pectoral pair, and in producing a large number (4 to 10) of young at a birth, all the others having usually but one or two. the peba armadillo, _t. septemcincta_, is a well-known species, having an extensive range from texas to paraguay. it is replaced in the more southern regions of south america by a smaller species, with shorter tail, the mulita (_t. hybrida_) so called from the resemblance of its head and ears to those of a mule. _t. kappleri_ is a large species from guiana. finally we have the pichiciago, or fairy armadillo, _chlamydophorus truncatus_, typifying the subfamily _chlamydophorinae_. in most anatomical characters, especially the structure of the fore-foot, this group resembles the _dasypodinae_, but it differs remarkably from all other known armadillos, living or extinct, in the peculiar modification of the armour. the teeth, which number 8/(8-9), are subcylindrical, somewhat compressed, moderate in size, and smaller at each end (especially in front) than at the middle of the series. skull broad and rounded behind, pointed in front. muzzle subcylindrical and depressed. a conspicuous rounded rough prominence on the frontal bone, just before each orbit. tympanic prolonged into a tubular auditory meatus, curving upwards round the base of the zygoma. vertebrae: c 7, d 11, l 3, s 10, ca 15. upper part of head and trunk covered with four-sided horny plates (with small thin ossifications beneath), forming a shield, free and overhanging the sides of the trunk, and attached only along the middle line of the back. the plates are arranged in a series of distinct transverse bands, about twenty in number between the occiput and the posterior truncated end, and not divided into solid scapular and pelvic shields with movable bands between. the hinder end of the body is abruptly truncated and covered by a vertically placed, strong, solid, bony shield, of an oval (transversely extended) form, covered by thin horny plates. this shield is firmly welded by five bony processes to the hinder part of the pelvis. through a notch in the middle of its lower border the tail passes out. the latter is rather short, cylindrical in its proximal half, and expanded and depressed or spatulate in its terminal portion, and covered with horny plates. the dorsal surfaces of the fore and hind-feet are also covered with horny plates. the remainder of the limbs and under surface and sides of the body beneath the overlapping lateral parts of the back shield are clothed with rather long, soft silky hair. eyes and ears very small, and concealed by the hair. extremities short. feet large, each 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 of _tatoua_ and _priodon_. teats two, pectoral. visceral anatomy closely resembling that of _dasypus_, the caecum being broad, short and bifid. the pichiciago, a burrowing animal, about 5 in. long, inhabits the sandy plains of western argentina, especially the vicinity of mendoza. its horny covering is pinkish, and its silky hair white. a second species, _c. retusus_, from bolivia is rather larger and has the dorsal shield attached to the skin of the back as far as its edge, instead of only along the median line. (see armadillo.) _tubulidentata._--the second suborder of edentates, namely the tubulidentata, is represented at the present day only by the aard-varks, or ant-bears, of africa, constituting the family _orycteropodidae_ and the genus _orycteropus_. together with the following group, they differ from the xenarthra in the absence of additional articular facets to the lumbar vertebrae; for which reason the term nomarthra has been proposed for the tubulidentata and pholidota as collectively distinct from the xenarthra. in the present group the external surface is scantily covered with bristle-like hairs. the teeth are numerous, and traversed by a number of parallel vertical pulp-canals. femur with a third trochanter. fore-feet without the first toe, but all the other digits well developed, with strong moderate-sized nails, suited to digging, the plantar surfaces of which rest on the ground in walking. hind-feet with five subequal toes. placenta broadly zonular. the brain is very like that of the ungulata; and there are two pairs of teats, one abdominal, and the other inguinal. aard-varks feed on animal substances; and are terrestrial and fossorial in habits. the total number of teeth is from eight to ten in each side of the upper, and eight in the lower jaw; but they are never all in place at one time, as the small anterior ones are shed before the series is completed behind. in the adult they number usually five on each side above and below, of which the first two are simple and compressed, the next two larger and longitudinally grooved at the sides, the most posterior simple and cylindrical. their summits are rounded before they are worn; their bases do not taper to a root, but are evenly truncated and continually growing. each tooth is made up of an aggregation of parallel dental systems, having a slender pulp cavity in the centre, from which the dentinal tubes radiate outwards, and being closely packed together each system assumes a polygonal outline as seen in transverse section. a series of milk-teeth is developed. skull moderately elongated with the facial portion subcylindrical and slightly tapering, and the zygoma complete and slender. the palate ends posteriorly in the thickened transverse border of the palatines, and is not continued back by the pterygoids. the tympanic is annular, and not welded to the surrounding bones. the lower jaw is slender anteriorly, but rises high posteriorly, with a slender recurved coronoid, and an ascending pointed process on the hinder edge below the condyle, which is small, oval, and looks forward as much as upwards. vertebrae: c 7, d 13,