114 SYNOPSIS. 
ORDINARIA. 
ARCHAEOTHERIUM. With a sagittal crest; orbits closed by a post-orbital arch; glenoid arti- 
culation transverse. Lower jaw with a basal apophysis as in Anthracotherium. Dental formula: 
?—? 1?—1? 4?—4? 3—3 
ae SG Se ae ey 
verse rows of three conical tubercles or lobes; the lower ones with two transverse pairs of tubercles, of 
which that antero-internally is subdivided. Last upper premolar bilobed; penultimate upper molar com- 
pressed conoidal. Last lower premolar compressed conoidal. 
in. Crowns of upper true molars quadrate, with two trans- 
1. ArncHAEOTHERIUM Morrtont. Head about the size of that of the Lion. 
2. ARCHAEOTHERIUM ROBUSTUM. Rather larger than the preceding. 
UNGULATA IMPARIDIGITATA‘ 
SOLIPEDIA. 
ANCHITHERIUM. With a short sagittal crest; forehead broad and large; orbits large. Dental 
3—3 1-1 7—7 
c. mM. : 
3—3 1—1 7—T7 
ANcHITHERIUM Barrpit. About the size of Anchitherium aurelianense. 
formula: in. Molars constructed after the type of those of Palaeotherium. 
ORDINARIA. 
TITANOTHERIUM. Dental formula as in Palaeotherium? Upper molars quadrate, complex, inter- 
mediate in form to those of Palaeotherium and Rhinoceros ; their outer side without the double arched 
ridge characteristic of the former, and without the anterior marginal fold characteristic of the latter. 
Lower molars like those of Palacotherium, but possessing no inner basal ridge. 
TITANOTHERIUM Proutiu. Unique species. 
== 2 1—1 4—4 3—3 
ALA i) : ental fi la tne ee C.D, ee ees 
PALAEOTHERIUM. Dental formula: x = c ai p-m a m a 
molars quadrate, complex ; with an external double-arched ridge. Lower molars bilunate; the last trilunate. 
4. Upper 
PALAEOTHERIUM GIGANTEUM. ‘Twice the size of the Palacotherium magnum ; being the largest spe- 
cies of the genus. 
RHINOCEROS. With a nasal or frontal horn, or both, or none. Dental formula: in. = 
1—1 2—2 0—0  7—7 
(= too) = aw: Upper molars quadrate, complex; with a characteristic antero- 
external fold. Inferior molars composed of a pair of right angled crescentoid lobes. 
OH 
1. RwINOcEROS occrDENTALIS. With a sagittal crest; frontal horn none; nasal horn? forehead 
broad and flat. Three-fourths the size of Rhinoceros indicus. 
2. Ruinoceros NEBRASCENSIS. With a sagittal crest; frontal horn none; nasal horn? ‘Three- 
fourths the size of Rhinoceros occidentalis, 
