CARN2VORA. 



773 



3. Hystricomorpha. Porcupines (Hystrix), agoutis (Dasyprocfa)^ 



guinea-pigs (Cavia], and the S. American capybara (Hydro- 

 chorus^ the largest living Rodent, measuring about 4 ft. in 

 length. 



4, Lagomorpha. Hares and rabbits (Lepus), and the picas or 



tailless hares (Lagomys), with incisors -. 



In the first three sub-orders there is only a single pair of upper 

 incisors, and the three may be united as Simplicidentata, in contrast 

 with the Duplicidentata, where there are two pairs. Only in the latter 

 does the enamel extend to the posterior surface of the incisors, which 

 are also peculiar (in this order) in having well-developed milk pre- 

 decessors. 



FIG. 416. Skull of tiger, lateral view. 



PX.> Premaxilla ; mx., maxilla. Note the insertion of upper canine 

 (c. 1 ) just behind the suture line, and the fact that the lower 

 canine (c. z ) bites in front of it. na., Nasals ; la., lachrymal 

 bone with foramen;./}'., frontal; pa., parietal; so., supra- 

 occipital ; pa., paroccipital process ; au., auditory aperture (the 

 reference line crosses the inflated bulla) ; sg., zygomatic process 

 of squamosal; a., angle of lower jaw; /., jugal ; ca., 

 carnassial tooth of upper jaw ; co., coronoid process of lower 

 jaw. 



Order CARNIVORA 



This order includes lions and tigers, foxes and dogs, bears 

 and otters, etc. 



Most of the Carnivora feed on animal food, and the most 

 typical forms prey upon other animals and devour their 



