CAVIID.E. 253 



Genus NESOCERODON, Schlosser l . 



Cheek-teeth semi-rooted, otherwise very similar in general struc- 

 ture to Issiodoromys, from which the present writer is inclined to 

 doubt the propriety of separating the genus. The structure of the 

 teeth in different stages of wear is well exhibited in Schlosser's 

 figures, loc. cit. pi. vii. It will be seen that the well-worn upper 

 molars represented in fig. 12 present precisely the same general 

 pattern as those of Issiodoromys figured by P. Gervais in the Zool. 

 et Pal. Frangaises, 2nd ed. pi. xlvii. fig. 6 a. 



Nesocerodon quercyi, Schlosser 2 . 

 Hob. France. 



M. 1348 d. Part of the right ramus of the mandible, containing the 

 incisor and the first three cheek-teeth; from the Upper 

 Eocene of Caylux (Tarn-et-Garonne), France. This speci- 

 men agrees with the mandibles figured by Schlosser, loc. 

 cit. pi. vii. figs. 1, 7, 21. Purchased, 1884. 



Nesocerodon minor (Filhol 3 ). 

 Syn. Issiodoromys minor, Filhol 4 . 



This species is smaller than the last, but it is not impossible that 

 it will ultimately be found that there is a transition in this respect 

 between the two ; in which case the present name should stand for 

 the species. 



Hob. France. 



M. 1631. Fragment of the left maxilla, containing the four cheek- 

 teeth; from the Upper Eocene of Caylux (Tarn-et-Garonne), 

 France. This specimen agrees very closely with the one 

 described by Filhol, loc. cit., and those figured by Schlosser, 

 loc. cit. pi. vii. figs. 8, 16, 20. The length of the space 

 occupied by the four cheek-teeth in the present specimen 

 is 0,008, in Filhol's specimen 0,0075, and in Schlosser's 

 specimens 0,007 and 0,0065. Purchased, 1884. 



1 Palseontographica, vol. xxxi. p. 16 (1884), Nesokerodon. 



2 Loc. cit. p. 19. 



8 Ann. Sci. Geol. vol. vii. art. 7, p. 52 (1876), Issiodoromys. 

 * Loc. cit. 



