462 



tween the squamosal and exoccipital. The zygoma is massive, but is less developed than in 

 the Manatee. 



Presented by the Zoological Society of London. 



2550. The petrotympanic bone and otosteals, or 'ossicula auditus/ of the Halicore 

 indicus. The otosteals consist of the malleus, incus, and stapes. 



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



2551. The cochlea and ossicula auditus of a Dugong. 



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



2552. The ossicula auditus of a Dugong. 



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



The following are parts of the same skeleton of a Malayan Dugong (Halicore indicus): 



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



i 



2553. The first cervical vertebra, or atlas. 



The transverse processes are imperforate, and are represented by short and tuberous par- 

 apophyses and diapophyses : the neural arch is perforated on each side near its anterior 

 border. 



2554. The second cervical vertebra, or dentata. 



The transverse processes are represented by diapophyses only, and are consequently im- 

 perforate. 



2555. The third cervical vertebra. 



2556. The fourth cervical vertebra. 



Its right transverse process only is pierced by the vertebral artery. 



2557. The fifth cervical vertebra. 



Its transverse processes are simply notched by the vertebral artery. 



2558. The seventh cervical vertebra. 



The left transverse process only is pierced by the vertebral artery. The lower lateral part 

 of the centrum bears on each side an articular facet for the head of the first dorsal rib. 



