SKELETON OF AKTIODACTYLA 



479 



The skull of the Barking-deer ( Cervus Muntjak) is remarkable 

 for the great length of the persistent pedicles (fig. 328, c, c) 

 which support the antlers, and which are continued from two 

 strong ridges that traverse the outer side of the frontal bone from 

 its junction with the nasals. The lacrymal presents a deep and 

 well-marked fossa, anterior to which is the antorbital vacuity. 

 The sockets of the upper canines are largely developed in the 

 maxillaries. 



In all Riuninants, and especially the horned kinds, the tem- 

 poral fossa; are small, the zygomatic arches weak, the coronoid 

 processes of the mandible fig. 319, g, narrow, the base of the 

 ascending ramus expanded; in short, the attachments of the 

 biting muscle are restricted, those of the chewing muscle ex- 

 panded. That for the masseter is shown by the ridge and 

 fossa continued forward from the zygoma below the orbit : that 

 for the ' pterygoidei ' by the 



backwardly produced and 329 



rounded angle of the lower 

 jaw. The exceptions to the 

 edentulous premaxillaries 

 have been noted. The arti- 

 cular surface for the mandi- 

 ble is broad, slightly convex, 

 with a posterior semicircular 

 channel bounded by a ridge. 



The hyoid arch includes 

 long, compressed, hammer- 

 shaped * stylohyals,' fig. 329, 

 1, having at their promixal 

 end the articular, a, and muscular, h, jirocesses, the short ^ epi- 

 hyals,' 2, the ceratohyals, 3, the basihyal, a,, and thyrohyals, 5 ; 

 attached to posterior angular processes of the basihyal. 



C. Bones of the Limbs. — Artiodactyles have the limbs ter- 

 minated by feet of 4 or 2 toes, in symmetrical pairs : but, as in 

 other Ungulates, almost restricted to locomotive functions. The 

 Hippopotamus and the Gazelle manifest in the even-toed series 

 analogous extremes in the proportions of the limbs, as do the 

 Rhinoceros and Horse in the Perissodactyles. The blade-bone 

 is long and narrow ; but the spine is more commonly produced 

 into an acromial angle in the Artiodactyles. In the Hi2:)po- 

 potamus, fig. 305, this angle is slightly produced : the coracoid 

 is recurved. The greater tuberosity of the humerus is divided 

 into two subequal processes, the inner one separated by a deep 



Hyoid arch, Sliecp. 



