14 UNGULATA. 



M. 2431. Fragment of aright maxilla, with m. 3 ; from the Middle 

 Eocene of Issel (Aude), France. This tooth is rather 

 larger than the specimen figured by Gaudry in ' Lcs 

 Enchainements, &c. Mammifures Tertiaires,' p. 69, fig. 70 

 (reproduced in fig. 4), and provisionally referred to this 

 species, but smaller than that of P. argentonicus figured on 

 p. 161 of the same work. Purchased, 1885. 



Pachynolophus prevosti, P. Gervais l . 

 Syn. Lophiodon prevosti, Riitimeyer 2 . 



This species is somewhat smaller than the last, with which it 

 agrees in the general characters of the upper molars. 

 Hob. Europe. 



M. 2430. Fragment of the left maxilla, containing the three true 

 molars (m. 1 broken) ; from the Middle Eocene of Gentilly, 

 near Paris. The first tooth agrees exactly with the one 

 figured by Gervais in the Zool. et Pal. Franchises, 2nd ed. 

 pi. xxxv. fig. 16. The length of the space occupied by 

 the three true molars is about 0,029. Purchased, 1885. 



Pachynolophus siderolithicus (Pictet 3 ). 

 Syn. Hyracotlierium siderolithicum, Pictet 4 . 



This species is still smaller than the last ; it is referred by Gaudry 

 to the present genus. 

 Hdb. Switzerland. 



M. 2432. Several fragments of maxillae, showing the true molars : 

 from the Eocene of Mauremont, Switzerland. The length 

 of the space occupied by the three true molars is 0,021 in 

 one specimen. The teeth agree precisely with the one 

 molar figured by Gaudry in ' Les Enchainements, &c. 

 Mammiferes Tertiaires,' p. 161, fig. 214. It appears very 

 difficult to distinguish Anchitherium siderolithicum, Riiti- 

 meyer 5 , from the present form. Purchased, 1885. 



Zool. et Pal. Frai^aises, 1st ed. vol. ii. Exp. No. 35 (1848-52). 

 Denkschr. schw. Ges. Nat. vol. xix. art. 3, p. 54 (1862). 

 Paleontologie Suisse ser. i. Vertebres de la Faune Eocene,' p. 175 (1869); 

 Hyracotherium. 

 Loc. cit. 

 Denkschr. schw. Ges. Nat. vol. xix. art. 3, p. 28, pi. iv. fig. 59 (1862). 



