I O Department of Vertebrate P alceontology . 



21. Heptodon calciculus Cope. 

 Palate and Complete Lower Jaws. 



Amer. Mus. No. 294. 



Primitive Lophiodont from the Wind River Eocene of Wy- 

 oming. Probably ancestral to the Colodons of the American 



Oligocene. 



Price, $7. 



OsBORN & WoRTMAN, Fossil Mammals of the Wasatch and Wind River 

 Groups, Collection of 1891, Bull. Amer. Mus. Nat. Hist., IV, 1892, 

 p. 127. 



22. Colodon dakotensis Osborn & Wortman. 

 Upper Jaws. 



Am. Mus. No. 1212. 



White River Oligocene, S. Dakota. 



Price, $3. 



23. Colodon occidentalis (Leidy). 

 Lower Jaws and Fore Foot. 



Am. Mils. No. 658, 



White River Oligocene, S. Dakota. 



This rare Lophiodont is known only by fragmentary speci- 

 mens. The group is intermediate between Tapirs and Horses 

 in some respects, between Tapirs and Rhinoceroses in others. 



It left no descendants. 



Price, $j. 



Osborn & Wortman, Perissodactyls of the Lower Miocene White 

 River Beds, Bull. Amer. Mus. Nat. Hist., VII, 1895, p. 362, fig. 7. 



Wortman & Earle, Ancestors of the Tapir from the Lower Miocene of 

 Dakota, Bull. Amer. Mus. Nat. Hist., V, 1893, p. 174, figs. 6 and 7. 



