528 CHORDATA. 
words, to shorten the whole mandible. This shortening is 
carried to an extreme in the cat and gives the face of the 
animal its peculiar “‘ round” appearance. 
As smaller anatomical differences which are valuable in 
classification, note the alisphenoid canal in the dog but 
none in the cat, and the larger auditory bulla in the latter, 
inside which there is a more complete bony septum. 
Fig. 365.—THE PERMANENT TEETH OF THE WOLF. (Nat. size.) 
j . 
Note sniall pointed incisors, large canines and cusped molars. The large 
fourth upper premolar bites on the large first lower molar 
and both are the carnassial teeth. 
The vertebral column of the dog and cat call for little 
mention. Both have the same number of vertebre, cervical 
7, dorsal 13, lumbar 7, sacral 3, caudal 18-22. The dorso- 
lumbar are 20, compared with 19 in the ox and 23 in the 
horse. They have very little, if any, tendency to the opistho- 
ceelous condition of the horse and ox. The tail is usually 
long and flexible and is put to a variety of purposes. 
