48 



SIMIID^. 



detected far back in its socket, is still very rudimentary and much, less developed 

 than in the more adult skull of the previous specimen. 



In the British Museum example of M. brunneus the only permanent teeth in the 

 upper jaw are the first molar and the first incisors, which are only partially exposed ; 

 the second pair of permanent incisors are only appearing behind and internal to the 

 milk pair ; the two milk- molars have not been shed. The second permanent molar 

 is seen deep in its alveolus, but only imperfectly developed. In the type of M. 

 brunneus the only permanent tooth is the first molar. 



In the lower jaw of the Liverpool monkey the permanent teeth are through 

 the jaws, but the canines and the last molar are only partially so. The type of 

 M. melanotus has all its permanent teeth in the lower jaw except its canines and the 

 last molar ; the former are only on a level with the jaw, and it appears as if the 

 milk-incisors had been shed, or, it may be, lost in the preparation of the skull. 

 The last molar is only very imperfectly developed and far back in its socket. In 

 the lower jaw of the British Museum specimen of M. brunneus the milk-canines 

 and two molars are still in the jaw ; the second permanent molar is not above the 

 surface and is only a shell ; there is no trace of the last tooth. The lower jaw of 

 the type of 31. brunneus has all its milk-teeth and its first molar. 



The dentition of M. melanotus, Ogilby, thus proves it to be an older specimen 

 than the British Museum example of M. brunneus, which in its turn is older than 

 the type in India. The skull characters of the last mentioned have been elsewhere 

 described,^ and the second example agrees with it except in a few trifling details whicli 

 do not merit enumeration. The skull of M. melanotus also is in no wise separable 

 from these two skulls — a statement which is borne out by the tabulated measure- 

 ments which I here gire, any little differences that do exist being legitimately 

 referable to individual peculiarities : — 



Occipital to premaxillsa 



Anterior margin of occipital foramen to premaxillse 



Anterior margin of occipital foramen to palate . 



Fronto-nasal process to premaxillje 



Auditory process to auditory process 



Auditory process to tip of premaxillse, in straight line 



Greatest breadth of skull behind root of zygoma 



Breadth across orbito-malar suture 



Least breadth in temporal fossa 



Breadth across zygomatic arch, at middle . 



Breadth of muzzle at base below maxillo-malar suture 



Breadth of muzzle at middle, anterior end opposite nasals 



Height of orbit 



Length of orbit 



Length of lower jaw in line with alveolar margin 



Macacus arcioides. Is. Geoff. St.-Hil. 



type sp. 



In. 



4-30 

 2-65 

 1-15 

 1-77 

 2-14 

 2-50 

 2-65 

 2-45 

 1-90 

 2-73 

 1-60 

 1-25 

 •83 

 1-00 

 2-30 



brunneus, 

 B. M. sp. 



In. 



440 

 2-90 

 1-15 

 1-60 

 2'52 

 2-75 

 2-80 

 2-52 

 1-87 

 310 

 1-66 

 1-40 

 •77 

 •95 

 2-82 



M. 



melano- 

 tus, 



B. M. sp. 



Id. 



4 46 

 2-99 

 1-27 

 1-81 

 2^40 

 2-90 

 2-68 

 2-50 

 1-87 

 2-95 

 1-65 

 1-30 

 •82 

 •95 

 2-76 



M. 

 arctoides. 

 B. M. sp. 



In. 



5-30 

 3-70 

 1-52 

 2-05 

 2-78 

 3-60 

 3 '04 

 3'03 

 1-90 

 3-50 

 1-96 

 1-48 

 •80 

 1-20 

 3-35 



M. 

 rvfescetis. 



In. 

 4-25 

 2^95 

 1^23 

 1-63 

 2-30 

 2-90 

 2-60 

 2-40 

 1-80 

 2^25 

 1-65 

 1-25 

 ■71 

 •90 

 2-75 



' Proc. Zool. Soc. 1872, pp. 203-212. 



