ON SKULLS OF HORSES FROM THE ROMAN FORT AT NEWSTEAD. 561 



otherwise adapted for living in the vicinity of forests, is more primitive than varieties 

 specialised for a steppe or a plateau life. 



Taking this for granted, I decided to study first a Newstead skull which seemed to 

 belong to a horse of the Forest type, i.e. a skull with a short, broad face. 



It has long been realised that in some ruminants the facial portion of the skull is 

 nearly in the same line with that of the cranium, while in others the face is bent 

 downwards so as to form a marked angle with the cranium. In the elk, e.g. when the 

 skull is placed so that the basi-cranial axis is horizontal, the nose is directed forwards ; 

 while in the sheep, with the skull placed in the same position, the nose is directed 

 downwards.* 



To an expert in equine skeletons, the skulls from the Roman fort at Newstead which 

 most closely approach the Forest type would probably not appear very remarkable : 

 being neither very long nor very bent nor irregular in outline, they would probably be 

 regarded as fairly typical skulls of what used to be termed the common horse. Never- 

 theless the Newstead skulls, with a short, broad, dished face, belong to a very distinct 

 type. They are especially characterised by (1) the large frontal index ; (2) the outline 

 of the face being concave ; (3) the face being, as in the elk, only slightly bent on the 

 cranium ; and (4) by the elevated position of the distal portion of the nasal bones. In 

 the 547 mm. Newstead skull of the Forest type (PI. I. fig. 1) the length of the face 

 is 372 mm., the width 228 mm. — hence the frontal index is 61*29 ;t in the long-faced 

 Steppe variety from Newstead the frontal index may be as low as 50, in E. grevyi it 

 may be only 47. The frontal index is high in the Forest variety, because the face is 

 broader and at the same time shorter than in the Steppe and Plateau varieties. 



Quite as distinctive as the high frontal index is the outline of the face. From the 

 highest point of the cranium to the summit of the eminence formed by the free distal 

 portions of the nasals, the outline is concave (PI. II. fig. 6). This "dished" condition 

 of the face is partly due to the distal portions of the nasals being elevated, and partly 

 to the absence of a prominence in the region of the frontal sinuses and over the 

 proximal portions of the nasal, fossae. 



In ungulates adapted for a forest life, e.g. the tapir and elk, the nasals are usually 

 short and arched upwards apparently to add to the mobility of the upper lip. In like 

 manner (though not nearly to the same extent) horses of the Forest variety are 

 specialised, the nasals being both shorter and more arched upwards than in, for example, 

 Prejvalsky's horse, a member of the Steppe variety. 



In descriptions of the skull of the horse it is frequently stated that the basal line 

 of the cranium, from the lower border of the foramen magnum to the incisor border of 

 the palate, is very nearly straight.^ 



* The difference in the relation of the face to the cranium in these two forms is perhaps accounted for by the 

 fact that the elk is a short-necked Forest form adapted for feeding on shrubs and trees, i.e. for holding the head in a 

 nearly horizontal position, while the sheep is a denizen of the mountains, adapted for holding the head when feeding 

 in a nearly vertical position. 



t For other indices, see Table I. % Flower and Lydekker, Mammals, Living and Extinct, p. 389. 



