Io8 Bulletin American Museum of Natural History. [Vol. XIV, 



II. — Revision and Discussion of Species/ 



(2) Equus curvidens Owen. 



Type Locality. — Punta Alta in Bahia Blanca, Argentina, S. A. 



Horizon. — Found together with remains of Megatherium, Megalonyx, etc. 



Type. — Superior m^ ; little worn. 



Author's description. — " A greater relative antero-posterior diameter than in 

 the recent horse, but especially is it distinguished by the greater degree of in- 

 curvation of the upper molars." 



Men suremeft ts . 



2 J Antero-posterior diameter 27 mm. 



(Transverse " 24 " 



This species must remain rather indeterminate until better 

 material reveals its true distinguishing characters. Although 

 Leidy at one time referred to it some Equus teeth found in the 

 United States and, so far as defined above, some of the teeth in 

 the American Museum collection might be placed in this species, 

 the probability is that E. curvidens differs from any of the North 

 American species, owing to its wide geographical separation from 

 them. 



(3) Equus major De Kay. 



Type Localities. — Neversink Hills, N. J.; north bank of Susquehanna near 

 Georgetown, D. C; North Carolina. 



Types. — Indeterminate, cited by author as follows : " Some teeth and verte- 

 bras belonging to the genus Equus." 



Authorls description. — " They [the teeth and vertebrae] resemble those of the 

 common domestic horse ; but from their size, apparently belong to a larger 

 animal." 



E. major is practically a nomen nudum, as no figures or measure- 

 ments were ever given and it seems impossible now to locate the 

 original specimens. 



(4) Equus americanus Leidy. 



Leidy first applied this term to three superior molar teeth (Fig. 

 7) from Natchez until he ascertained that it was preoccupied by 

 Gervais for a South American type; he then substituted the term 

 E. complicatus. 



' For dates, location of types, etc., see Chronological Table, p. 107. The names of valid 

 species are in heavy-faced type. 



