36 GUIDE TO THE AUSTRALIAN MUSEUM. 



The Sperm Whale {Physeter macrocephalns) is of equal 

 importance in commerce to the Baleen Whale on account of the 

 spermaceti found in the cavity of the head, and the sperm oil 

 from its blubber. Its mouth is not provided with whalebone, 

 but has permanent teeth in the lower jaw. There is a skeleton 

 supported oveihead in the Australian Hall. The whale, from 

 which it was taken, was caught off Wollongong in November 

 18G0, and was over 70 feet long. Over the cases in the same 

 Hull are specimens of smaller species of Sperm Whales — 



Mesoplodon thomsonii, ^ , ^, 



'- both very rare species. 



Dioplodon seychellensis, J 



and in the Osteological Hall other skeletons and skulls will be 

 found, including several of the rarer species, as Gray's Whale 

 (Ko(/ia breuiceps), &c. 



The Dolphins and Porpoises also belong to the order 



Cetacea. The common Dolphin {Deljyhinus) is found in the 

 Atlantic and Mediterranean, but a species closely resembling 

 it occurs on the Australian coast and elsewhere, while other 

 species or varieties are found all over the world. The Porpoise 

 ditiers slightly from the Dolphin in outward appearance but 

 chiefly in the shape of its head and form of its teeth. The 

 species which is familiar to boatmen in Port Jackson is how- 

 ever a Dolphin, having teeth in both jaws. The "Killer" 

 (Orca) is the Grampus. Mounted specimens are to be seen 

 in the Central Hall, Upper floor. Skeletons of Dolphins, Por- 

 poises, and Grampuses are also to be found in the Osteological 

 Hall. 



The Manatees and DugOngS form the order Sirenia 

 (from the Greek Seiren a Mermaid), and are very peculiar animals. 

 They inhaV»it the estuaries of the large rivers and the bays of the 

 tropics. There are skeletons of two species of Manatees and 

 one of the Dugong in the Osteological Hall, and mounted speci- 

 mens in the Central Hall, Upper floor. 



The Manatee — [Manatus australis) of South America, and 

 (il/. senegalemis) of Western Africa. 



