509 



2943. Most of the bones of the cranium of a very young African Rhinoceros (Rhino- 

 ceros bicornis). 



The crowns of the second and third deciduous molars are beginning to protrude from their 

 formative alveoli. The alisphenoids are connate with the basisphenoid, and the orbito- 

 sphenoids with the presphenoid. The pterygoid processes developed from the alisphenoids 

 are perforated at their base by the ectocarotids. 



Purchased. 



2944. The lower jaw of the same foetal or very young African Rhinoceros. 



The dried gum which covered the anterior end of the bone has been removed, to expose 

 the four rudimental incisors, two ou each side of the symphysis, the outer one being the 

 largest. 



Purchased. 



The following, to No. 2958 inclusive, are parts of the same skeleton of the African Rhi- 

 noceros (Rhinoceros bicomis) : 



Hunterian. 



2945. The atlas. 



The transverse processes are large, horizontally flattened, quadrate plates : the left one is 

 perforated, the right notched, by the vertebral artery, which afterwards perforates the neural 

 arch. An anterior notch indicates the original division between the bases of the neurapo- 

 physes behind which the hypapophysis developes a compressed process. 



2946. The axis. 



The transverse process is moderately long, slender, and perforated at its base ; beyond 

 which the articular surfaces for the atlas extend outwards on each side. A rough ridge is 

 developed from each side of the summit of the neural spine. 



2947. The fifth cervical vertebra. 



The pleurapophysis extends downwards and a little outwards, expanding into a broad sub- 

 quadrate plate : the diapophysis is thicker, shorter, and more obtuse than in the axis, and 

 the perforation for the vertebral artery is considerably larger : there is a metapophysial tubercle 

 exterior to the prozygapophysis. The neural spine is slender and simple. The centrum 

 presents an articular ball in front and a corresponding cup behind. 



2948. An anterior dorsal vertebra. 



It is remarkable for the great length and terminal expansion of the neural spine. There 

 are three costal articular surfaces on each side those of the centrum, which retains the form 

 of the cup and ball. 



