3 1 6 Btdletin American Museum of Natural History. [Vol. XVI.] 



1. Hypertragulus calcaratus Cope. White River, Oreodon 



Beds. 



H. tricostatus Cope.^ Not H. calcaratus "Cope" Scott, Trans. 

 Wagn. Inst. Sci., 1899. 



2. Hypertragulus sp. indesc. John Day. 



Hypertragulus calcaratus Scott, Trans. Wagn. Inst., 1899, pi. i, 

 figs. 3-4. 



The John Day specimens referred by Profs. Cope and Scott 

 to H. calcaratus are a larger, more brachydont species, with 

 heavier muzzle, etc. 



3. "Hypertragulus" transversus Cope. White River, 

 Titanotherium Beds (?), Swift Current Creek. 



Cope, Mem. Geol. Sur. Can. Ill, 1S91, 22. 



Twice the hnear size of H. calcaratus, para- and meta- 

 cones uniformly convex externally, small para- and metastyles 

 and prominent hypostyle anterointernal to hypocone. It is 

 not at all probable that this species is Hypertragulus or re- 

 lated thereto. 



Hypisodus Cope. 



Dentition, I|- C\ V"^!^- Mf. Lower canine incisiform, first pre- 

 molar small, probably incisiform. Second upper and lower premolars 



decadent at anterior end of grind- 

 £^ \^ ing series. Teeth hypsodont, skull 



^~~\_^v.^__AJ\Mt .._ \ very brachycephalic, but muzzle 



\j»!^J^s.J-r:^iiTvsv "'-'os.jJ rather long and slender. Pre- 



lachrymal vacuity irregular, orbits 



very prominent, bullae very large. 



p,. ^ ^.^. f ZL7 „■ J Lateral digits of pes extremely 



rig. 4. Dentition ot Hypisodus. b r- j 



slender although still entire; no 

 cannon-bone; ulna and radius united. 



I. Hypisodus minimus Cope. White River (Oreodon clays). 



^. " • • . I know but the one species, the H. calcaratus Cope." — Cope, Proc. Amer. 

 Phil. Soc, 1884, Vol. XXII, p. 24. This statement invaHdates H. tricostatus, and quite 

 correctly so. 



