RHYVTINIDA 221 
The Dugongs are more distinctly marine in their habits than the 
Manatees, feeding chiefly on sea-water alge. They inhabit the 
shallow bays and creeks of the Red Sea, east coast of Africa, 
Ceylon, islands of the Bay of Bengal and the Indo-Malayan 
Archipelago. (including the Philippines), and the north coast of 
Australia, ranging from Barrow Reefs on the west to Moreton Bay 
on the east. Although the distinctive characters are not very 
obvious, they have been divided into three species, according 
to the localities which they respectively inhabit :—Z. tubernacult 
from the Red Sea, H. dugong from the Indian seas, and A. australis 
from Australia. The last-named has lately been the object of a 
regular “fishery,” chiefly on account of its oil, which is peculiarly 
clear, limpid, and free from disagreeable smell, and is said to have 
the same medicinal properties as cod-liver oil. Although often stated 
in books to attain the length of 20 feet when adult, there does 
not appear to be any evidence from actual specimens in museums 
that Dugongs ever reach half that size, 8 feet being the common 
length of adult animals. 
The placentation of this genus has been recently described by 
Sir W. Turner, who first indicated its zonary form. 
Family RHYTINIDA. 
Ehytina.tNo teeth, their place being supplied functionally by 
the dense, strongly-ridged, horny oral plates. Premaxillary rostrum 
about as long as the anterior narial aperture, and moderately 
deflected. Vertebree: C7,D19, Land C 34-37. Head very small 
in proportion to the body. Tail with two lateral pointed lobes. 
Pectoral limbs small and truncated. Skin naked and covered with 
a very thick, hard, rugged, bark-like epidermis. Stomach without 
cecal appendages to the pyloric cavity. Czcum simple. 
Only one species of this genus is known, J. stelleri, the Northern 
Sea-cow, by far the largest animal of the order, attaining the length 
of 20 to 25 feet. It was formerly an inhabitant of the shores of 
two small islands in the North Pacific, Behring and the adjacent 
Copper Island, on the former of which it was discovered by the 
illfated navigator whose name the island bears, when, with his 
accomplished companion, the German naturalist Steller, he was 
wrecked upon it in 1741. Twenty-seven years afterwards (1768), 
as is commonly supposed, the last of the race was killed,” and its 
1 [lliger, Prodromus Syst. Mamm. et Avium, p. 141 (1811).—Amended from 
Rytina. 
2 Nordenskiéld, during his voyage in the Vega, obtained some information 
from the natives of Behring Island which led him to believe that a few individ- 
uals may have survived to a much later date, even to 1854; but this conclusion 
is disputed by later writers. 
