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general build the llamas and horses; they have small brains, and a facet on the calcaneum for the fibula. The cheek-dentition approximates more or less to the perissodactyle type. Both the terminal faces of the cervical vertebrae are flat, the femur carries a third trochanter, the bones of both the carpus and See also:

TARSUS (mod. Tersous)

tarsus are arranged in linear See also:

SERIES (a Latin word from serere, to join)

series, and the number of toes, although commonly three, varies between one and five, the third or See also:

MIDDLE

middle See also:

DIGIT (Lat. digit us, finger)

digit being invariably the largest. Of the two families, the first is the Proterotheriidae, which exhibits, in respect of the reduction of the digits, a curious See also:

PARALLELISM, PSYCHOPHYSICAL

parallelism to the equine See also:

LINE

line among the See also:

PERISSODACTYLA (i.e. odd-toed)

Perissodactyla; in this feature, as well as in the reduction of the See also:

TEETH (O.E. Eel); plural of tooth, O.E. top)

teeth, it is more specialized than the second See also:

FAMILY

family. The molar teeth approximate to the See also:

PALAEOTHERIUM (i.e. ancient animal)

Palaeotherium type, but have a more or less strongly See also:

DEVELOPED

developed median See also:

LONGITUDINAL

longitudinal cleft. The three-toed type is represented by Diadiaphorus, in which the dental See also:

formula is i.i,c.?, p m.l,and the feet are very like those of Hipparion. The cervical vertebrae are of normal See also:

FORM (Lat. forma)

form, the See also:

ORBIT (from Lat. orbita, a track, orbis, a wheel)

orbit (as in the second pair of upper incisors are somewhat elongated, and have a See also:

gap between and behind them, while the See also:

OUTER

outer See also:

LOWER

lower incisors are larger than the inner pair, the canines being small. The See also:

SKULL

skull has a See also:

SHORT, FRANCIS JOB (1857– )

short muzzle, with elongated nasals. Remains of this and the other representatives of the group are found in the Patagonian See also:

MIOCENE

Miocene. In Proterotherium, which includes smaller forms having the same, or nearly the same, dental formula, the molar teeth differ from those of Diadiaphorus by the deeper median longitudinal cleft, which completely divides the See also:

CROWN

crown into an inner and an outer moiety, the two cones of the inner See also:

HALF

half being See also:

UNITED

united. According to the description given by See also:

ARGENTINE

Argentine palaeontologists, this genus is also three-toed, the single-toed representative of the family being Thoatherium, in which the lateral metapodials, or splint-bones, are even more reduced than in the See also:

EQUIDAE

Equidae.

In the second family—Macraucheniidae—the dentition is See also:

COMPLETE

complete (See also:

FORTY

forty-four) and without a gap, the crowns of nearly all the teeth being of nearly See also:

UNIFORM

uniform height, while the upper molars are distinguished from those of the Proterotheriidae by a See also:

PECULIAR

peculiar arrangement of their two inner cones, and the See also:

ELEVATION

elevation of the antero-posterior portion of the cingu]um so as to form an extra See also:

PIT (O. E. pytt, cognate with Du. put, Ger. Pfutze, &c., all ultimately adaptations of Lat. puteus, well, formed from root pu-, to cleanse, whence gurus, clean, pure)

pit on the crown. To describe this arrangement in detail is impossible.here, but it may be stated that the two inner cones are closely approximated, and separated by a narrow V-shaped notch on the inner See also:

side of the crown. The elongated cervical vertebrae are peculiar in that the See also:

arch is perforated by the artery in the same manner as in the llamas. In the See also:

SANTA

Santa Cruz beds of See also:

PATAGONIA

Patagonia the family is represented by the generalized genus Oxyodontotherium (in which Theosodon may apparently be included). It comprises animals ranging up to the See also:

SIZE

size of a See also:

TAPIR

tapir, in which the nostrils were more or less in the normal anterior position, and the cheek-teeth short-crowned, with the inner cones of the upper molars well developed and separated by a notch, and the pits of moderate See also:

DEPTH

depth. The last upper premolar is simpler than the molars, and the canine, which may be See also:

double-rooted, is like the earlier premolars. The See also:

RADIUS

radius and ulna, like the See also:

TIBIA

tibia and fibula, are distinct, and the metapodials rudimentary. On the other See also:

hand, in Macrauchenia, which was a much larger See also:

LLAMA

llama-like See also:

animal, the skull is elongated and narrow, with rudimentary nasals, and the See also:

APERTURE (from Lat. aperire, to open)

aperture of the See also:

NOSE (O.Eng. nosu, cf. Dutch neus, Swed. nos, snout; the Aix in Provence. Both at Aix and at Lyons he acquired great connexion with O.Eng. nasu is obscure, cf. Ger. Nase, Lat. pares, distinction by his labours during outbreaks of the plague. In nostrils,

nose placed nearly on the line of the eyes and directed up-wards, the muzzle not improbably terminating in a short See also:

TRUNK (Fr. tronc, Lat. truncus, cut off, maimed)

trunk. Deep pits on the forehead probably served for the See also:

ATTACHMENT

attachment of See also:

SPECIAL

special muscles connected with the latter. Very curious is the structure of the cheek-teeth, which are high-crowned, with the two inner cones reduced to See also:

mere points, and the pits on the crown-See also:

SURFACE

surface large and See also:

FUNNEL (through an O. Fr. founil, found in Breton, from Lat. infundibulum, that through which anything is poured, from fundere, to pour)

funnel-shaped. In fact, the perissodactyle type is almost lost. The cervical vertebrae and See also:

LIMB

limb-bones are very See also:

long, the radius and ulna being completely, and the tibia and fibula partially, united.

The typical M. patagonica is a See also:

PLEISTOCENE

Pleistocene form as large as a See also:

CAMEL (from the Arabic Djemal or the Heb. Gamal)

camel, ranging from Patagonia to See also:

Brazil, but remains of smaller See also:

SPECIES

species have been found in the See also:

PLIOCENE (from the Gr. sr?eiov, mere, and xatvbs, recent)

Pliocene (?) of See also:

BOLIVIA

Bolivia and See also:

ARGENTINA

Argentina. The imperfectly known Scalabrinia of the Argentine Pliocene appears to occupy a position intermediate between Oxyodontotherium and Macrauchenia, having the nasal aperture situated in the middle of the length of the skull, and the crowns of the cheek-teeth nearly as tall as in the latter, but the lower molars furnished with a projecting See also:

PROCESS

process in the hinder valley, similar to one occurring in those of the former. In this See also:

PLACE (through Fr. from Lat. platea, street; Gr. IrAar6s, wide)

place may be mentioned another See also:

STRANGE, SIR ROBERT (1721-1792)

strange ungulate from the Santa Cruz beds of Patagonia, namely, Astrapotherium, sometimes regarded as typifying a suborder by itself. This huge ungulate had cheek-teeth singularly like those of a See also:

RHINOCEROS

rhinoceros, and an enormous pair of tusk-like upper incisors, recalling the upper canines of See also:

MACHAERODUS, or MACHAIRODUS

Machaerodus on an enlarged See also:

scale. In the lower See also:

JAW (Mid. Eng. jawe, jowe and geowe, O. Eng. cheowan, connected with " chaw " and " chew," and in form with " jowl ")

jaw are two large tusk-like canines, between which are three pairs of curiously-formed spatulate incisors, and in both jaws there is a long diastema. The dental formula appears to be i.3i c.9, p., m.3. Next Astrapotherium may be provisionally placed the genus Homalodontotherium, of which the teeth have much lower crowns, and are of a less decidedly rhinocerotic type than in Astrapotherium, and the whole dentition forms an even and unbroken series. The bodies of the cervical vertebrae are short, with flattened articular 792 surfaces, the humerus has an enormous deltoid See also:

crest, suggestive of fossorial See also:

POWERS, HIRAM (1805-1873)

powers, and the femur is flattened, with a third trochanter. According to the Argentine palaeontologists, the carpus is of the alternating type, and the terminal phalanges of the pentedactyle feet are bifid, and very like those of See also:

EDENTATA

Edentata. Indeed, this type of See also:

FOOT

foot shows many edentate resemblances. The astragalus is square and flattened, articulating directly with the navicular, although not with the cuboid, and having a slightly See also:

CONVEX

convex facet for the tibia. From the structure of the above-mentioned type of foot, which is stated to have been found in association with the skull, it has been suggested that Homalodontotherium should be placed in the See also:

ANCYLOPODA, or ANCYLODACTYLA

Ancylopoda (q.v.), but, to say nothing of the different form of the cheek-teeth, all the other South American Santa Cruz ungulates are so distinct from those of other countries that this seems unlikely.

It may be suggested that we have rather to See also:

DEAL

deal with an instance of parallelism—a view supported by the parallelism to the Equidae presented by certain members of the Proterotheriidae. (R.

End of Article: LITOPTERNA

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