19 



syceras differs in the angulation of the profile between the horns, and in the very close 

 position of the horns. The entire width of the muzzle at the horns is not greater 

 than the elevation of the horns themselves. 



I may add that the bones of the skeleton described under the head of the M. angusti- 

 genis may well belong to the present species, or, vice versa, the horns and muzzle here 

 described may belong to the species represented by the lower jaws, to which the name 

 M. angustigenis has been given. In that case the name M. syceras becomes a synomyn, 

 and the front and nasal bones described under the M. angustigenis must be referred to a 

 different species ; perhaps the M. color adoensis. 



C^INOPUS, Cope. 

 American Naturalist, 1887, pp. 925, 1000. 



CLenopus occidentalis, Leidy. 



Cope I. c, Rhinoceros occidentalis, Leidy, Proceeds. Acad. Philadel., 1850, p. 119 ; 1851, p. 276 ; Ancient Fauna 

 of Nebraska, 1853, p. 81, plates sii, xiii; Aceratherium occideniale, Leidy, Proceeds. Acad. Philadel., 1854, p. 157; 

 Extinct Mammalia Dakota and Nebraska, p. 220, pi. xxi, fig. 34 ; xx, xxiii, 1-3. 



The only specimen from the Cypress Hills which represents this species is a fragment 



of a right mandibular ramus supporting a damaged last molar tooth. The dimensions 



of the parts are as follows : — 



Mm. 



( Anteroposterior 38 



Diameters of M. iii. 1 



[ Transverse 26 



Width of ramus at base of coronoid 33 



C.ENOPUS MITIS, Cope. 



American Naturalist, 1887, p. 925 ; Aceratherium mite, Cope, Annual Report U. S. Geol. Survey Terrs., 1S73 

 (1875J, p. 493. 



Fragments of mandibular rami of two individuals represent this species. The mea- 

 surements are as follow : — 



Measurements. 



No. 1. 



Mm. 



( Anteroposterior 25 



Diameters of base of M. iii. J. 



( Transverse 16.5 



Depth of ramus M. iii 42 



Width of ramus at base of coronoid 20 



No. 2. 



C Anteroposterior 24 



Diameters of M. i. -j 



( Transverse 19 



Depth of ramus at M. i 43 



Cjenoptjs pumiltjs, Cope. 



Aceratherium pumilum, Cope, American Naturalist, 18S5, p. 103 (name only) ; Annual Report G. & N. H. Sur- 

 vey, Canada, 1885, App. C, p. 83. 



Portions of mandibles of two individuals represent this, the smallest of the Khinocer- 



ontidse. One of the rami possesses the alveoli of the large recumbent canine teeth, indicating 



