1092 The Artiodactyla. 
AT 
The MERYCOPOTAMIDÆ embrace but one genus, Merycopotamus: 
C. and F., which is a form of considerable interest. Its superior 
molars display the simple quadriselenodont type of the later fam- 
ilies, but in the lower jaw 
the primitive condition of 
but one series of crescents 
still remains. Several spe- 
cies are known, all from 
the upper miocene of India. 
The OREODONTIDZ is 
the prevalent type of Arti- 
odactyla during Miocene 
time in North America. 
Their characters are as fol- 
lows :— 
Dentition : superior 
incisors present ; molars 
selenodont. Cervicals with 
brarterial canal. No alis- 
phenoid canal, Ulna and 
radius, and tibia and fibula 
distinct. Metapodial bones 
four on each foot, with 
incomplete distal troch- 
lear keels. Lunar bone 
not supported by magnum 
Navicular a cuboid 
bones distin 
The details a the struc- 
true express various affin- 
ities. The axis is inter- 
mediate between that of 
the suilline and ruminant 
Artiodactyla; the other 
oe eg rig ee eee cervicals are suilline, while 
size, 
rom Kentucky. the remaining vertebre 
uilline; while the 
are ruminant. The scapula is ruminant, not $ 
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