123 p. N. BOSE ON FOSSIL CARNIVORA 



only one mental foramen ; and this, or, if there are two (as in a 

 specimen of the lower jaw of M. neogceus in the British Museum 

 collection), the posterior of these is situated in front of a vertical 

 line drawn from the front base of tho anterior premolar ; whereas 

 in the Lion or the Tiger, in which there is always more than one> 

 mental foramen, the hindermost is situated behind that line. The 

 canine and the first false molar are indicated by their alveoli ; in 

 antero-posterior length the latter is larger than the corresponding 

 tooth of M. meganthereon. The next molar (pm. 4) and the car- 

 nassial are in sitic, but they are both damaged; they are about 

 the same size as the corresponding teeth in the Brazilian 3fa- 

 chcerodus. 



The remaining specimens consist of the posterior portion of a 

 skull* and a nearly entire, but mutilated, cranium f, which has 

 been a good deal crushed. 



They present the following peculiarities : — • 

 . 1. The facial portion is considerably less in length than the 

 cranial. This is a peculiarity common to the other species of Ma- 

 cJicerodus, and also to the Felis cristata of Ealconer, which, as noticed 

 by that learned comparative anatomist, is the only large feline 

 animal that presents this Hysenoid characteristic. 



2. The sagittal crest, which is very prominent, slopes gradually 

 in front up to its point of bifurcation. This characteristic is also 

 shared by the other two species of IfacJicerodus, and, it is interesting 

 to observe, by Felis cristata and F. grandicristata (?) alone of all the 

 larger forms of Felis. 



3. The zygomatic process of the squamosal is prolonged vertically 

 downwards so as to form a strong and stout pedicel, separated by a 

 narrow valley from the mastoid. 



4. The mastoid portion of the periotic is of much greater extent, 

 and is prolonged further downwards than in either the Lion or the 

 Tiger. 



5. The occipital crest is very high. 



The following measurements of M. meganthereon^ and also of the 

 bones of the skull and the upper-jaw teeth of M. neogceus^ have 

 been taken from the beautiful figures in De Blainville's Atlas :|: ; the 

 measurements of the lower jaw of the last species have been taken 

 from two specimens in the collection of the British Museum : — 



^ B. M. no. 39728 ; figs. 1, U, 15, \c, impubhshed pi. N (F. A. Sir.). 

 t B. M. no. 39729 ; figs. 2, 2a, &c., unpublished pi. N (F. A. Siy.). 

 \ Osteographie, Atlas, genus Felis, pis. xvii. and xx. 



