i68 



MAMMALIA— ORDER VII.—SIRENIA. 



T^'ig- 92.— Ddooko (Hatieore dugong). 



equally developed in both sexes, form simple cylinders, increasing in size from 

 the first to the last, the latter being more complex than those in advance, 

 and consisting of two cylinders united by a narrow bridge. Although usually 



measuring from 5 to 7 feet in 

 length, dugong grow to as much 

 as from 8 to 9 feet. In colour 

 they are generally bluish -grey 

 throughout,butinsome examples 

 the under-parts are more or less 

 decidedly lighter. The essential 

 difference between the dugong 

 and manatis in the matter of 

 habits is that the former is essen- 

 tially a marine animal which 

 never attempts to ascend rivers, 

 and its food consequently con- 

 sists entirely of seaweed of 

 various kinds. In former days 

 dugong were met with in herds 

 comprising hundreds of individuals, which were remarkable for their extra- 

 ordinary tameness and fearlessness of man. Human greed has, however, done 

 the usual work, and now their haunts are tenanted only by solitary individuals 

 or pairs, which are shy and difficult of approach. Dugong oil is valued fur 

 its extremely limpid character ; and in Timor-Laut these animals are hunted 

 by the natives for the sake of their tusks, from which ear-rings and other 

 ornaments are manufactured. 



To their comparatively wide geographical distribution may be attributed 

 the escape of the manatis and dugong from complete extermination ; but the 

 rhytina, or northern sea-cow {Ehytina gigas), which, at the 

 Northern time of its discovery in 1741, existed in numbers on the 

 Sea-Cow. shores of the Commander group of islands in Behring 

 Strait, soon fell a victim to the persecution of man. In- 

 deed, it appears that within less than thirty years from the date when its 

 haunts were first invaded by Behring's pirty, the rhytini had ceased to 

 exist ; and it is now known to us only by certain descriptions and a number 

 of more or less well-preserved skeletons which have been disinterred from 

 its former haunts. In size the northern sea-cow vastly exceeded all its 

 allies, being stated to attain a length of between 20 and 30 feet, with 

 a weight in some cases of upwards of eight thousand pounds. It was 

 evidently the most specialised member of the group, teeth being entirely 

 wanting, and their function discharged by horny plates on the surfaces of 

 the mouth, while the extremities of the flippers were blunted, and the bones 

 of the digits apparently wanting. The head was small in proportion to the 

 size of the body, and the tail was more deeply forked than in the dugong. 

 So rough and ragged was the thick epidermis of the naked skin, that it has 

 been compared to the bark of an oak tree, and could only be cut by an axe. 

 While one account states that the colour of the skin was generally uniform 

 brown, although occasionally flecked with whife, a drawing taken from life 

 shows alternate dark and light transverse bandings. 



