388 



OSTEOLOGY AND 



with numerous tubercles. The carnassial tooth is often, but 

 by no means always, very much larger and especially longer 

 than the rest of the molar and premolar series. It is less 

 pronounced in some of the omnivorous Arctoidea. The skull of 

 the Carnivora is longer in the more primitive types, such as the 

 Canidae, and shorter in the more specialised Felidae. The orbit 

 is hardly ever completely shut off by bone, though the postorbital 

 process of the frontal sometimes approaches the corresponding 

 upward process of the zygomatic arch. The palate, which is 

 completely ossified, sometimes reaches back for some distance 

 behind the teeth ; it always extends as far as the last molar. 

 The tympanic bulla is often very inflated, and if flatter, as in the 

 Bears, is at any rate large and conspicuous. The lower jaw has 



FIG. 191. A, Atlas of Dog. Ventral view, x ^. B, Axis of Dog. Side view, x 4f. 

 o, Odontoid process ; pz, posterior zygapophysis ; s, spinous process ; sn, foramen 

 for first spinal nerve ; t, transverse process ; v, vertebrarterial canal. (From 

 Flower's Osteology.) 



a high coronoid process, and the condyle is transversely elongated, 

 this part of the bone being rolled into an almost cylindrical 

 form ; it fits very closely into the glenoid cavity, and the 

 articulation is thereby very strict an obvious advantage in a 

 creature with so great a need for power of jaw. 



In the vertebral column the atlas always has large wing-like 

 processes ; the spine of the axis vertebra has a long antero- 

 posteriorly elongated form. The transverse processes of the 

 fourth to the sixth cervicals are, as a rule, double. These 

 features, however, though characteristic of the Carnivora are not 

 by any means distinctive. The true sacrum consists of but a 

 single vertebra to which the ilia are attached ; but at most two 

 other vertebrae are fused with this. The clavicle is always small 

 and sometimes quite rudimentary, or even absent. The spine of 

 the scapula is well developed, and almost equally divides the 



