EXTINCT MAMMALIA OF NORTH AMERICA. 399 



adopted DeKay's name of E. americanus. The earlier one, E. Jackscnii, applied to a 

 specimen by an anonymous writer, as he observes, for convenience from the place 

 near which it was found, if adopted, to be correct, should be E. Jacksonensis. 



In a recent visit to New Haven, Conn., in the Museum of Yale College I saw the 

 fragment of a lower molar of an Elephant, from near Keal del Monte, sixty miles 

 north of the city of Mexico. The tooth is of the coarse-plated variety, and presented 

 seven double plates and a single plate in a space of four and three-quarter inches. 



SOLIDUNGULA. 



EQUID^. 



EQUUS. 



Hqnns fossilis. 



Horse, Auckland : Beechey's Nar. Voy. Pacific 1831, Appendix, 595, PI. Ill, Figs. 

 Equus fossilis, Richardson : Zool. Voy. Herald 1854, 17. 



Remains found in the frozen cliffs of Eschscholtz Bay, Alaska, may probably be- 

 long to the same species as the Equus fossilis of Europe, the probable ancestor of the 

 Domestic Horse of to-day. Quaternary. 



£qaiis major. 



Horse, Equus, Mitchell : Cat. Org. Rem., N. York 1826, 7, 8. Cooper : Month. Am. Jour. Geol. 

 1831, 207 ; Am. Jour. Sc. 1831, XX, 371 ; Edinb. New Phil. Jour. 1831, XI, 353. Carpen- 

 ter : Am. Jour. Sc. 1838, XXXIV, 201, Figs. 1—3. Dickerson : Proc. Acad. Nat. Sc. 1846, 

 106. Leidy : Proc. Acad. Nat. Sci. 1847, 328, PI. Fig. 6, supposed new species. In part of 

 Tuomey : Rep. Geol. S. Carolina 1848, 165, 166, 208. Gibbes : Pr. Am. As. Adv. Sc. 1849, 

 II, 193, resembling E. plicidens ; 1850, III, 66, supposed new species. Holmes : Ibid. 68. 



Equus major, DeKay : Nat. Hist. New York, Zool. I, 1842, 108. Leidy : The present work, p. 265. 



Equus Americanus, Leidy : Pr. Ac. Nat. Sc. 1847, 265, PI. II, 328; 1851, 140 ; 1853, 241 ; 1854, 

 200. Gibbes : Pr. Amer. Assoc. Adv. Sc. 1849, II, 194 ; 1850, III, 66. Pictet : Traits de 

 Paleont. 1853, 1, 318. 



Equus complicatus, Leidy: Pr. Ac. Nat. Sc. 1858, 11; 1868, 175; Holmes' Post-pli. Fos. S. Carol. 

 1860, 100, PI. XV, Figs. 2—5, 7, 9, 11—15, XVI, Figs. 19—22, 24—26, 30, 31 ; The present 

 work, page 265. 



Remains of an extinct species, about as large as the corresponding parts of the 

 largest living varieties of the Domestic Horse, found in association with remains of 

 Mastodon americanus, Megalonyx Jeffersoni, etc. Molar teeth generally distinguishable 

 by the comparatively complex course of the enamel lines on the triturating surfaces. 



For the species I have adopted the name of DeKay, as it was evidently to this one 

 he refers, although he gave no distinctive character other than size. Quaternary. 



