MAMMALIA. 581 



habits and the structural modifications involved. The sub- 

 order Fissipedia are terrestrial and the Pinnipedia are 

 aquatic. 



SUB-ORDER I. — FISSIPEDIA. 



The Fissipedia (or Carnivora Vera) have always the full 

 complement of incisors (|), and one of the cheek-teeth in 

 each jaw is formed by the carnassial tooth (see page 525). 

 The limbs are formed for terrestrial locomotion and, as in 

 the typical pentadactyle limb, have the third digit as long as, 

 or longer than, the rest. 



The present day Fissipedia can be divided into the 

 yFluroidea, Cynoidea and Ardoidea, having affinities with 

 the cats, dogs and bears respectively. 



The yFluroidea are the most specialised. Their teeth 

 are reduced in number and the skull is shortened. They 

 are nearly all digitigrade. The characters of the auditory 

 region are found to form a useful distinction between these 

 and the other two divisions. Thus in the ^Fliiroidea the 

 auditory bulla is large, divided into two by an internal bony 

 septum and partially covered externally by the paroccipital 

 process of the exoccipital bone. 



Family I. — Felidae. — The Felidce comprise the true cats, with re- 

 tractile claws. Amongst them are the lion and leopard of the Ethiopian 

 and Oriental regions, the jaguar of Neogoea, the tiger of Asia, the puma 

 of America and the wild -cats and lynxes of Europe. 



Family 2. — Viverridae. — The Viverridce comprise the civets and 

 mongooses, found only in Arctogoea. They have more teeth than the 

 Felidcc and non-retractile claws. 



Family 3. — Protelidae. — The ProtelidcE consist of a single genus 

 (Pi'oteles), the aard-wolf of South Africa, a nocturnal burrowing animal 

 of degenerate necrophagous habits. 



Family 4. — Hyaenidae. — Lastly, the HycenidiB comprise the hyaenas 

 of Arctogoea, with more teeth than the FelidiB^ but with no septum to 

 the auditory bulla. 



The Cynoidea have a larger number of teeth {|y^|) and 

 longer jaws than the ^Fluroidea, in correlation with which 

 they are less strictly carnivorous. There is only a trace of 

 an auditory septum and the paroccipital process does not 

 overlap the bulla. They are mostly digitigrade but never 



