HY ENODONTID. re | 
portion of the skull figured by Filhol in the Ann. Sci. 
Géol. vol. vii. pl. xxix. fig. 143, showing the distinct 
anterior talon and the low crown of pm. 2, and differing 
thereby from No. M.1351 (4. brachyrhynchus). It appears 
that the present specimen cannot, however, be distinguished 
from the corresponding portion of the skull of H. aymarde 
figured by Filhol in the Ann. Sci. Géol. vol. xii. pl. vii., 
although that species is distinguished from 4. leptorhynchus 
by the presence of a distinct anterior talon to the last lower 
premolar. Purchased, 1884. 
M. 1671. Fragment of the left ramus of the mandible, containing 
the last premolar and the three true molars; from the 
Upper Eocene of Caylux. This specimen is precisely 
similar to the corresponding portion of No. M.1350. 
Purchased, 1884. 
4  M.1672. Fragment of the right ramus of the mandible, containing 
the last true molar; from the Upper Eocene of Caylux. 
The tooth has the elongated form characteristic of this 
species and H. cayluai; in the relatively greater depth of 
the jaw the present specimen agrees more nearly with 
fl, leptorhynchus than with H. cayluai. (Vide Filhol, 
Ann. Sci. Géol. vol. vii. art. 7, pp. 183, 206.) The 
dimensions of the specimen are compared below with 
those of the mandible of H. leptorhynchus described by 
Filhol, viz. :— 
Filhol. B.M. 
Meneth of Gamassial .. 4.2... 2... 0,018 0,019 
Height of first lobe of carnassial .. 0,010 0,010 
3 second ,, FF ** 0,006 0,007 
Depth of jaw at carnassial ...... 0,026 0,027 
Purchased, 1884. 
Hyzenodon dubius, Filhol’. 
This’ species is about the size of H. brachyrhynchus; from which 
it is at once distinguished by the much greater vertical depth of the 
mandible. 
Hab. France. 
M. 1676. Fragment of the right ramus of the mandible, containing 
the third and fourth true molars; from the Upper Eocene 
* Aun. Sci. Géol. vol. iii. art. 7, p. 29 (1872). 
