14 THE HORSE FAMILY. 



head, absence of forelock, upright mane, and tail sparsely haired 

 at the root. Indeed, the grounds for separating this race from 

 the next are based on considerations of nomenclature and con- 

 venience rather than on structural differences. Nevertheless, 

 the cheek-teeth appear to be relatively and absolutely smaller 

 in the cavern race, the length of the row of six upper teeth in 

 a specimen from Bruniquel being about 7^ inches. 



Skulls from the superficial deposits of Walthamstow, Essex, 

 of which one (N.H. 18) is exhibited in the table-case, probably 

 indicate a race nearly allied to, if not identical with, the Cave- 

 Horse. As in the Mongolian Wild Horse, the face is bent 

 downwards only in a slight degree on the line of the basal axis 

 of the skull. 



-- ,. The Mongolian Wild Horse [Equus cabalhis prze- 



^ valsLii, fia:. 14) is a small race, standina; about 



Wllrl llnrco ^ o / ^ o 



12 hands at the shoulder, and characterised by the root 

 of the tail being short-haiied, a short upright mane, the absence 

 of a forelock, and the yellow dun or somewhat rufous body-colour, 

 with the mane and tail black, the legs dark brown or black, at 

 least as high as the fetlocks, a narrow dark stripe down the back, 

 and generally (probably always when pure-bred) a white muzzle. 

 The head is relatively large, especially as regards the face, the 

 ears are proportionately tall, and the hoofs rather narrow. The 

 interval between the first upper cheek-tooth and the outermost 

 incisor is relatively very short. The cheek-teeth (fig. 16, A) are 

 both absolutely and relatively very large, the length of the upper row 

 of six in a skull with a basal length of 18|- inches being 7^ inches, 

 or only one-quartei- of an inch less than in the skull of the Shire 

 Mare '' Starhght'' (N.H. 23, fig. 16, B), of which the basal length 

 is 23 inches. Other distinctive features of the upper cheek-teeth 

 are the absence of complex foldings in the enamel and the 

 relatively large size (antero-posteriorly) of the anterior pillar {a), 

 which is produced considerably in advance of the point of con- 

 nection with the main body of the tooth, and is much flattened 

 on the inner side. This feature is most pronounced in the 

 premolars. The large relative size of the cheek-teeth is illustrated 

 by comparison with those of a Dartmoor Pony skull (N.H. 27), 



