996 The Perissodactyla. [Nov 
Š ee.” 
In the Lophiodontine line we have Helaletes (Marsh) without 
diastema, like Systemodon. In Heptodon the diastema appears, E 
Ma 
Fic. 6. Fore-leg and foot of HHyraco- 
therium venticolum Cope, two-thirds nat- 
from front; 4, ulna and radius from be- 
hind; c; anterior foot from before. i 
i In 
and in the succeeding genera the first premolars de 
Hyrachyus the heel of the last inferior molar vanishes, Y% 
e nasal bones bear traces of dermal horns in C 
close 
Passage to the Tapiride is equally easy, through R he 
resemblance of Protapirus (Filh.) to Tapiravus (Marsh) ° 
