244 



Speciincii ot Fig. "2, representing a second ur third molar : 



Lines. 



LcTigtb externally 127 



Autero-posterior diameter of triturating surface 15j 



Transverse diameter 13i 



A tooth in the collection of" the Smithsonian Institntion, apparently refer-- 

 al)le to the same species, was discovered by Mr. Clarence King on Sinker 

 Creek, Idaho. 



Equus major. 



Figs. 3 to 1 7, Plate XXXIII, represent specimens, from different localities 

 of the United States, which are viewed as pertaining to an extinct horse, 

 originally referred by the author to a species under the name of Equus com- 

 plicatus, and which is suspected to be the same as that which was first desig- 

 nated by Dr. Dekay under the name of Equus major. 



Figs. 3, 4, 7 to 10, 12, 13, represent specimens of teeth submitted to my 

 examination by Messrs. D. C Elliot and George N. Lawrence, of New York. 

 They were obtained from an asphaltum-deposit and from a stratum of clay 

 beneath, in Hardin County, Texas, and were found in association with remains 

 of mastodon and other extinct animals. 



Figs. 3, 4 represent a first upper molar of the right side. It differs in no 

 important degree from the corresponding tooth of the domestic horse, l)ut is 

 somewhat larger than usual, and is less simple in the course of the enamel 

 lines on its triturating surface. 



Figs 5, 6 represent a similar tooth, from Illinois Bluffs, Missouri, six miles 

 west of Saint Louis. According to the late Dr. B. F. Shumard, it was derived 

 from the quaternary formation of Missouri. 



Figs. 7, 8 represent a last superior molar of the right side, accompanying 

 the first molar, from Hardin County, Texas. It is remarkable for its great 

 extent of curvature compared with the corresponding tooth in the recent 

 horse. The arrangement of the enamel is similar to that in the latter, and is 

 but little more complex than usual. 



Fig. 9 represents a last lower molar, and Fig. 10 a fifth lower molar. These 

 present nothing peculiar distinguishing them from the corresponding teeth of 

 the recent horse. 



Fig. 11 represents a second or third upper molar of the right side. The 

 specimen was found liy Dr. Thomas H. Streets, in a gully of Galveston Bay, 



