Dey NGOOP iS: Es 
OF THE 
GENERA AND SPECIES OF EXTINCT MAMMALIA AND CHELONIA DESCRIBED IN THIS WORK. 
MAMMALIA. 
UNGULATA PARIDIGITATA. 
RUMINANTIA. 
POEBROTHERIUM. Hornless; without lachrymal fossee; auditory bull very large and inflated ; 
i —aiF 
orbits closed by a post-orbital arch. Lower jaw with an angular apophysis. Dental formula: dn. “: = 
1?—1? 4—4 38—3 _ o99 
ra ae es ae 387 
most like those of the recent Musks; first premolar removed from the others by a hiatus. 
True molars composed as in existing ruminants; premolars 
PoEBROTHERIUM Witsonu. Unique species. 
AGRIOCHOERUS. Hornless; without lachrymal fossee; orbits open behind. Dental formula: 
3?—3? 1?—1? 4?—4? 3—3 9 $ 
=D a 44? True molars constructed after the type of those 
of existing ruminants; premolars with from one to four lobes, modified in form from those of the true 
molars. 
AGRIOCHOERUS ANTIQUUS. Unique species. 
in 
OREODON. Hornless; with a sagittal crest; with the pars-squamosa of the temporal bone relatively 
as well developed as in the Camel; auditory bulla none; orbits closed behind; very large lachrymal 
ioaaes ee hee Siete 
4—4 1—1 3—3 38—3 
nearly closed rows. True molars constructed after the type of those of existing ruminants; premolars 
with one or two lobes. Upper canine with a curved, trihedral, pyramidal crown; lower canine with a 
compressed conoidal crown. Incisors with flattened crowns. 
1. OrEopon CuLBeRtsonit. About the size of the Wolf of Pennsylvania. 
fossee. Dental formula: in. —44, Teeth of both jaws forming 
2. OREODON GRAciIuis. About two-thirds the size of the former. 
3. OrEODON Magor? A little larger than Oreodon Culbertsonii. 
EUCROTAPHUS. Cranium constructed like that of Oreodon, except that it possesses large, inflated 
auditory bulla. Dental formula: as in Oreodon ? 
1. Evcrorapnus Auritus. Auditory bull laterally compressed spheroidal. 
2. Eucrorarnus JAcKsont. Smaller than the preceding; auditory bullz mammillary. 
