i 9 6 THE SKULL. [CHAP. 



compressed ridge. The large tympanohyals are entirely em- 

 bedded in the tympanic, only the rough lower surface for 

 articulation with the stylohyal being exposed. 



The mandible and hyoid are like those of the Sheep, but 

 the basihyal is rather more developed, and has a rounded, 

 anterior, median projection. 



Many Ruminants (especially among the Cervidcc} have a 

 vacuity of varying extent on the side wall of the face, 

 between the frontal, lacrymal, maxillary and nasal bones, 

 leading in the macerated skull into the nasal chamber, but 

 closed in the living animal by membrane. Most of the 

 Deer and Antelopes have also a large depression on the 

 facial surface of the lacrymal bone, called the suborbital or 

 lacrymal fossa, though it has nothing to do with the tears, 

 but lodges a glandular fold of the integument, which secretes 

 a peculiar unctuous and odorous substance. In most Deer 

 the orifice of the lacrymal canal is double, and situated on 

 the margin of the orbit, whereas in most of the hollow- 

 horned ruminants it is single and placed well within the 

 margin. There are however exceptions in both cases. 



In the Deer the axis of the face is nearly in the same 

 line with that of the cranium, so that when the basicranial 

 axis is horizontal the nose is directed forwards instead of 

 downwards, as in the Sheep and Ox. The animals of this 

 family have no permanent horn cores continuous with the 

 cranium and ensheathed by true horns, but have short pro- 

 cesses on the frontal bones (pedicles], from which branching 

 antlers of true osseous structure are annually developed and 

 shed. These, as a rule, are only present in the males, 

 while the horns of the Bovida and Antilopida are usually 

 common to both sexes. 

 _. Among the Antelopes, the Saiga (Saiga tartaricd) is very 



