pillar of the last premolar and first molar is only about one-third the length of the crown (Fig. 59), while the length of the metacarpal instead of being 5.5 is 7.5 times the width at the middle of the shaft (Fig. 56).

As it happens, the slender-limbed 12.2 hands Newstead pony, in its molars and metacarpals, agrees with a race which in Pleistocene times ranged from Algiers to the South of England. It is hence possible that the Arab-like 12.2 hands ponies were brought to Scotland by 'Gaulish' cavalry from a district where the native breeds had been improved by foreign horses originally brought from Spain or North Africa, i.e. by horses belonging to Prof. Ridgeway's variety, Equus caballus libycus. The chief differences in the skull, teeth, and metacarpals of the 12.2 hands Newstead pony of the 'forest' type and the 12.2 hands slender-limbed pony of the 'Celtic' or 'Libyan' type will be made evident by comparing Figs. 1 and 2 (P1. XCV.) and Figs. 56 to 59.

Long, low, 12.2 hands ponies, with rounded hind quarters, a heavy mane, a low set-on tail, a short broad dished face, and short stout limbs are still often met with in Iceland. These modern representatives of the Elephant Bed and Solutré variety especially differ from the slender-limbed 'plateau' race in having four ergots and four chestnuts—in typical 'Celtic' and 'Libyan' ponies the hind chestnuts are absent as in asses and zebras, and there are no callosities at the fetlocks.

The slender-limbed 12–13 hands Newstead ponies are especially interesting, because they form a connecting link between modern ponies of the Celtic and Libyan types and the slender-limbed prehistoric races represented by teeth or limb-bones from the Pleistocene deposits of North Africa, Central France, and the South of England, and from Neolithic deposits. In the same way the 12–13 hands coarse-limbed Newstead ponies form a connecting link between the robust, long, low broad-

FIG. 58. Upper cheek teeth (nat. size) of an Iceland pony of the 'forest' type, with teeth practically identical with those of the Solutré horse (Equus robustus). The first premolar is absent; the internal pillar (p) of the third and fourth premolars and the first molar is long; the crown of p.m. 4 is twice the length of its pillar, and the crown of m. 1 less than twice the length of its pillar. Hence p.m. 3, p.m. 4, and m. 1 of the Iceland pony are more specialised than the corresponding teeth in a pony (Fig. 59) of the 'plateau' type.

FIG. 59. Upper cheek teeth (flat. size) of a Newstead pony ('plateau' type), about 12.2 hands high (for skull see Figs. 2, Pl. XCV., and 1, Pl. XCVI.). The two last molars (m. 2 and m. 3) closely resemble the two molars from Oreston, which formed the type of Owen's Asinus fossilis; the first molar (m. 1) is slightly more complex than m. 1 from Oreston, and still more complex than a molar from Lake Karar, Algiers; in the fourth premolar (p.m. 4), which resembles p.m. 4 of 'Eric,' a Shetland pony, and p.m. 4 of Equus sivalensis. (Fig. 60), the crown is nearly three times the length of its pillar instead of less than twice the length, as in Equus fossilis and modern cart-horses. The first premolar is about half the size of p.m. 1 in Equus sivalensis.

FIG. 60. Upper cheek teeth (nat. size) of Equus sivalensis. The first premolar (p.m. 1) is large and lying in front of pm. 2; the pillar of pm. 4 is shorter than the pillar of m. 2, but larger than the pillar of m. 1. Premolar 4, in having the pillar shorter than m. 2, agrees with the Newstead pony (Fig. 59) and horses of the 'plateau' type, but differs from the Iceland pony (Fig. 58) and horses of the 'forest' and 'steppe' types. Though Equus sivalensis is the oldest true horse known, it has more highly specialised teeth than the Oreston and Newstead ponies. After Lydekker. Palaeontologia Indica, Ser. x. vol. ii.