94 THE MAMMALIA OF THE DEEP RIVER BEDS. 



much wider than in Mioliippus. The magnum surface is entire, and that for the 

 unciform is larger and more oblique. This latter facet is divided into two parts by 

 a sulcus, which hardly more than emarginates that for the magnum. It seems prob- 

 able that a rudiment of the fifth metacarpal was preserved, for which a facet shows 

 on the head of mc. iv. 



Measurements. 



M. 



Breadth of radius and ulna, dislal end 035 



Depth of radius, distal end 018 



Height of lunar 015 



Width of lunar, distal end 012 



Width of unciform facet 004 



Width of mc. iii, proximal end 021 



Depth of mc. iii, proximal end 014 



Found in the upper beds of Deep river by O. C. Mortson. 



ANCHITHERIUM von Meyer. 



Teeth bracbyodont, without cement; upper molars and premolars with the pos- 

 terior transverse crest confluent with the outer wall of the crown ; conules so much 

 reduced as to be scarcely distinguishable from the remainder of the crests ; external 

 crescents deeply concave and overhanging ; in the lower cheek teeth the anterior pil- 

 lar is reduced, and on more or fewer of the teeth is wanting; posterior pillar also 

 reduced ; incisors, either the upper alone, or both upper and lower, with shallow pits. 



"Whether the coossification of the meso- and entocuneiforms is a generic charac- 

 ter remains to be seen. 



Anchitiierium equestum Scott. 



Amer. Naturalist, 1893, p. 661 . 



This animal may be at once distinguished from all other American horses by 

 the generic characters given above, since this is the only known American species of 

 Ancliiilierium in the restricted sense in which I have used that term. From the 

 best-known European species, A. aurelianense, it differs in the following respects: 

 (1) Larger size of the teeth in proportion to the skeleton; (2) absence of enamel 

 invaginations in the lower incisors ; (3) smaller size of the antero-external buttress 

 on p^2 ; (4) the transverse crests of the upper molars and premolars are less sinuous ; 

 (5) pTa has the anterior half of the crown flattened on the outside and no external 

 valley ; (6) the diastema between the lower canine and pTi is relatively shorter and 

 the symphysis much narrower; (7) the proximal end of the humerus differs in details 



