THE FLESH-EATING PREDATORY MAMMALS 117 



divided up into complex lobes marked by deep inflections of 

 enamel (like the zigzag ridges so often met with in Rodents 

 and Ungulates). The stomach is always a simple pear-shaped 

 bag, and the cascum is either absent or short and simple in most 

 (but not all) cases. The mammae vary in number from one pair 

 to six pairs. The clavicle, or collar bone, is frequently absent, 



THE UPPER CARNASSIAL TOOTH (FOURTH PREMOLAR) IN VARIOUS CARNIVORES. 



I. In Common Seal (Phoca vitulina), two-rooted. 



n. In an extinct Creodont of the Eocene period 

 (Proviverra), three-rooted. 



in. In Bear ( Ursus arctus), two-rooted. 



iv. In Glutton (Gnlo of the Weasel group), three- 

 rooted. 



v. In the Wolf (Canis lupus), three-rooted. Very 

 similar in all other existing members of the 

 genus Canis. 



VI. In Otocyon (the Long-eared Fox), 

 vn. In Lion. 

 VHI. In a Machairodont (Mathairodus neogaus). 



and, if present, is in a rudimentary condition and incomplete. 

 There are other marked features in the bones of the limbs which 

 are characteristic of this group, but which it is not necessary to 

 describe here. In the True Carnivores, or FffJtpedia, the first 



