754 



MAMMALIA. 



placenta is (a) indeciduate, and diffuse or cotyledonary ; 

 or (b) deciduate and zonary. 



Ungulata Vera : ARTIODACTYLA and PERISSODACTYLA 



ARTIODACTYLA PIGS, CAMELS, 

 CHEVROTAINS, AND RUMINANTS. 



PERISSODACTYLA TAPIRS, 

 RHINOCEROS, HORSES. 



The third and fourth digits of each 

 foot are equally developed, and 

 the line halving the foot runs 

 between them. 



The premolars and molars are 

 usually different, hut generally 

 bunodont or selenodont. 



There are nineteen dorso-lumbar 

 vertebrae. 



The femur has no third trochanter. 



The astragalus has always equal 

 articular facets for the navicular 

 and for the cuboid. The cal- 

 caneum has an articular facet for 

 the fibula, if that bone is fully 

 developed. 



The stomach tends to be complex, 

 and the csecum is small. 



The mammae are few and inguinal, 

 or numerous and abdominal. 



The placenta is diffuse or cotyle- 

 donary. 



There are often bony outgrowths 

 from the frontals. 



There is no alisphenoid canal. 



The third digit occupies the middle 

 of the foot, is largest, and is 

 symmetrical on itself, so that the 

 line halving the foot bisects the 

 third digit. 



The premolars resemble the 

 molars. 



There are almost always twenty- 

 three dorso-lumbar vertebrae. 



The femur has a third trochanter. 



The astragalus has a large facet 

 for the navicular, a small facet 

 for the cuboid. The calcaneum 

 does not articulate with the 

 lower end of the fibula (except 

 Ala era uchen ia]. 



The stomach is always simple, and 

 the caecum is large. 



The mammae are always inguinal. 



The placenta is always diffuse. 



There are never bony outgrowths 



from the frontals. 

 There is an aMsphenoid canal 



transmitting the txternal carotid 



artery. 



Sub-Order ARTIODACTYLA. Even-toed Ungulates 



Pigs and Hippopotamus (Suina), Camels (Tylcpoda), 

 Chevrotains (Tragulina), and Ruminants (Pecora; like 

 Cattle and Deer. 



The general characters of this sub-order have been stated 

 above in contrast to those of Perissodactyla. The equal 

 development of the third and fourth digits, the fact that the 

 premolars have a single lobe while the molars have two, the 



