506 



2929. The proximal phalanx of the outer toe. 



2930. The middle phalanx of the outer toe. 



2931. The ungual phalanx of the outer toe. 



2932. The right femur vertically and longitudinally bisected. 



The canal for the medullary artery, which commences anterior to the small trochanter, ex- 

 tends downwards to open into a small medullary cavity at the middle of the shaft of the bone. 



Genus Rhinoceros. 

 Dental formula : i ^,p^,m 1=36. 



Note. The incisors are rudimental, and are absorbed in the African Khinoceroses with two 

 horns, one or both of which horns attain a great size. When the incisors are developed, the 

 median pair is the largest in the upper jaw and the smallest in the lower jaw, and the small 

 incisors are commonly lost early in both jaws. This is the case likewise with the first pre- 



molar in both jaws, which is disproportionately small. 







2933. The skeleton of a Sumatran Rhinoceros (Rhinoceros sumatrensis). 



The vertebral formula is : 7 cervical, 1 9 dorsal, 3 lumbar, 4 sacral, and 22 caudal. It 

 has acquired the permanent dentition, and retains three premolars and three true molars on 

 each side of both jaws. The epiphyses of the long bones have coalesced with their respect- 

 ive shafts. The pleurapophyses, from the fourth to the sixth cervical vertebrse inclusive, 

 have the form of broad subquadrate plates : in the seventh the diapophysis only is developed, 

 and the transverse process is consequently imperforate. The spine of this vertebra suddenly 

 acquires great increase of length, which continues more gradually to the second and third 

 dorsals, beyond which the spines quickly shorten, but gain in antero-posterior extent to the 

 eleventh dorsal, beyond which they continue of the same size, shape and inclination to the 

 lumbar region. The ribs are slender in proportion to their length. The sternum and sternal 

 ribs are wanting in the present skeleton. 



Presented by Sir Stamford Raffles, P.Z.S. 



2934. The cranium of a male Sumatran Rhinoceros (Rhinoceros sumatrensis). 



The right incisor is wanting ; the molar series consists of p 4 4, m 3 3. The present 

 cranium offers no indication of the short hinder horn in this two-horned species. A smaller 



