IX

THE CONEYS

233

other hand they differ from most Ungulates in the incisors growing from persistent pulps, a point in which they resemble the Rodentia. The muffle also is split as in those animals. The Hyracoidea are peculiar in the fact that in addition to the caecum at the junction of the small and large intestines, there are a pair of caeca (bird-like in being paired) some way down the large intestine. The dorsal vertebrae are unusually numerous, 22. The adult dentition according to Woodward, who has recently examined the matter, is IC () Pm M 3, while the milk dentition is IC Pm 4.

The inclusion of the canine of the permanent set of teeth in brackets signifies that it is the milk canine which occasionally

persists.

It should further be remarked about the teeth that they are both hypselodont and brachyodont, the extremes being connected by intermediate forms. Another peculiarity of the genus is the dorsal gland, which is covered with hair of a different colour to that covering the body generally. This is present in all species.

The genus Hyrax (the most recent authority on the subject, Mr. Oldfield Thomas, only allows one genus) is limited in its range to Ethiopian Africa and to Arabia, including Palestine, It does not reach Madagascar. Mr. Thomas allows fourteen species with two or three sub-species.

1 M. F. Woodward "On the Milk Dentition of Procavia (Hyrax) capensis, etc," Proc. Zool. Soc. 1892, p. 38.

"On the Species of the Hyracoidea," Proc. Zool. Soc. 1892. p. 50.

234

HYRAX CHEWING THE CUD

CHAP. IX

Some of the Coneys live in rocky ground, while others, formerly placed in the genus Dendrohyrax, frequent trees, in holes in which they sleep. The Coney of the Scriptures is familiar, who is "exceeding wise," though a "feeble folk." But the further observation that he "cheweth the cud but divided not the hoof," is obviously entirely wrong. As to the wisdom, it is said that this beast is too wary to be taken in traps; while the suggestion of chewing the cud is, according to Canon Tristram, to be interpreted in the light of a habit of working and moving its jaws which the animal has. The traveller Bruce kept one in captivity to see if it did really chew the cud, and found that it did!

CHAPTER X

UNGULATA (continued)-PERISSODACTYLA (ODD-TOED

UNGULATES)-LITOPTERNA

SUB-ORDER 8.

PERISSODACTYLA

THESE Ungulates derive their name, which is that given by the late

FIG. 121. Bones of the manus A, of Tapir (Tapirus indicus). x. B, of Rhinoceros (Rhinoceros sumatrensis). x. C, of Horse (Equus caballus). × 1. c, Cuneiform; 7, lunar; m, magnum; P, pisiform; R, radius; s, scaphoid; td, trapezoid: tm, trapezium; u, unciform; U, ulna; II-V, second to fifth digits; V in B, and II and IV in C, represented by rudimentary metacarpals. (From Flower's Osteology.)

Sir Richard Owen, from the fact that the middle digit of the hand and foot is pre-eminent. As will be seen from Fig. 121, the axis of

236

FOOT OF UNGULATES

CHAP.

R

the limb passes through the third finger, which is larger than any of the others, and is symmetrical in itself. In this the present group contrasts with the Artiodactyla, where the axis is not "mesaxonic,” but where there are two digits, on either side of the axis, which are symmetrical with each other. This arrangement of the limbs is highly characteristic, but appears to be not quite universal. In the Titanotheres, which form a group of the Perissodactyles, the fore-limbs are not quite accurately mesaxonic. Nor on the other hand can all Ungulates which show the Perissodactyle condition. be safely included in the present group. The ancient Condylarthra and the Litopterna show precisely the same state of affairs. But other features in their organisation lead to their separation from the Perissodactyles, of which, however, the Condylarthra are probably ancestors. The Litopterna on the other hand, which possess even one-toed members like Equus, are believed to represent a case of parallelism in development. The number of functional toes varies from four to one. In the ankle joint the astragalus either does not, or does only to a comparatively slight extent, articulate with the cuboid as well as with the navicular bone. Moreover the fibula when present does not as a rule articulate with the Cuneiform; 7, lunar; m, calcaneum. In the opposed group of

IV

FIG. 122.

Bones of the manus of Camel (Camelus bactrianus). × 1.

magnum; R, radius; s,

scaphoid ta, trapezoid Artiodactyles the precise reverse of these ", unciform. (From conditions obtains. It is usually stated

Flower's Osteology.)

as part of the definition of this group that they do not possess horns of the type of those met with in the Cervicornia and Cavicornia. But the strong bony bosses on the skull of many Titanotheres, so curiously reminiscent of those of the not nearly related Dinoceras and Protoceras, may well have supported horns of the Ox and Antelope pattern.

The teeth of the Perissodactyles are lophodont, more rarely bunodont. The selenodont Artiodactyle form of molar is not met with. The dental formula, moreover, is at least near the

DIVISIONS OF PERISSODACTYLES

237

complete one, the more modern forms as usual being the more deficient in numbers of teeth.

The dorso-lumbar vertebrae are as a rule twenty-three; but the extinct Titanotheres are again an exception; for, at least in Titanotherium, there are but twenty of these vertebrae-an Artiodactyle character. The femur has a third trochanter. There are so few recent Perissodactyles that an enumeration of the distinguishing characters of the viscera may very probably be useless for purposes of classification. But the living genera at any rate are to be separated from the living Artiodactyles by the invariable simplicity of the stomach coupled with a very large and sacculated caecum. The liver is simple and not much broken up into lobes, and the gall-bladder is always absent. The brain is well convoluted. The teats are in the inguinal region. The placenta in this group is of the diffused kind.

The living Perissodactyles belong to three types only, indeed to three genera only (in the estimation of most), which are the Horses, Tapirs, and Rhinoceroses. But taking into account the extinct

t

right femur of Rhinoceros (Rhinoceros indicus). x. h, Head; t, great trochanter; t', third trochanter. (From Flower's Osteology.)

forms, they may be divided primarily FIG. 123. - Anterior aspect of (according to Professor Osborn) into the four following groups :-(1) Titanotherioidea, including but one family, Titanotheriidae; (2) Hippoidea, including the families Equidae and Palaeotheriidae; (3) Tapiroidea, with two families, Tapiridae and Lophiodontidae; and (4) Rhinocerotoidea with families Hyracodontidae, Amynodontidae, and Rhinocerotidae. It is conceivable, according to the same writer, that the Chalicotheres (here treated of as a separate sub-order, Ancylopoda) should be added to the Perissodactyle series.

Fam. 1. Equidae. This family, which includes the living Horse, Zebras, and Asses, as well as a number of extinct genera agreeing with those types in structure, may be defined by the possession of but one functional toe, the two lateral ones being mere splints, or but little more. The molar teeth are hypselodont, and