348 THE ANATOMY OF VERTEBRATED ANIMALS. 



articulate with convex facets developed upon the anterior 

 margins of the last lumbar and first sacral vertebrae re- 

 spectively. 



In the skuU, the plane of the supra-occipital is inclined 

 upwards and forwards, and gives rise to the middle part 

 of a transverse ridge which is continued at the sides into 

 the squamosal. The ridges which limit the origins of the 

 temporal muscles above, unite in the middle line poste- 

 riorly, and thus produce a low sagittal crest. The orbit is 

 bounded behind by the united postorbital processes of the 

 frontal and the jugal. The lachrymal aperture lies in the 

 orbit. The nasal bones unite, for a short distance only, 

 with the premaxiHa. There is no prsenasal bone. The pos- 

 terior margin of the palate is opposite the penultimate molar 

 tooth. The glenoidal surface is transversely elongated and 

 convex from before backwards. 



The tympanic buUa is not very large, and is rugose 

 inferiorly. It is not ankylosed with the surroimding bones. 

 The post-tympanic process of the squamosal does not 

 approach the postglenoidal process of the same bone, below 

 the tneatus auditorius. 



The proper mastoid process is distinct, but short. There 

 is a long and strong paramastoid developed from the ex- 

 occipital. 



The rami of the mandible are ankylosed at the symphysis. 

 The perpendicular part of each ramus is long, the condyle 

 transverse and convex from before backwards, and the narrow 

 coronoid process rises far above the level of the condyle. In 

 a longitudinal section of the skull the cerebral chamber lies 

 almost altogether in front of that for the cerebellum. 



The structure of the limbs of the Horse is such as 

 might be expected from its pre-eminent cursorial powers. 



That excessive development of the epidermis which gives 

 rise to a nail takes place, in the Horse, not only upon the 

 dorsal surface of the tenninal joint of the digit, but upon 

 its ventral surface and sides, and thus produces a lioof. 



The animal is supported by these greatly-developed nails, 

 and hence is said to be unguligrade. The long axes of its 



