THE MANATIS AND DUGONGS. 167 



young is held between the flippers of the female parent and pressed close to her 

 breast, upon which are situated the single pair of teats ; and as both parent 

 and offspring hold their rounded and somewhat human-shaped heads above 

 water, there is no reasonable doubt that it is these animals that have given 

 rise to the old legends of mermaids and mermen. The representatives of 

 both the existing genera are usually found associating in small herds, their 

 range including the coasts of the warmer portions of the Atlantic Ocean, the 

 Red Sea, Indian Ocean, parts of the Bay of Bengal, and the seas of Australia. 

 The northern sea-cow was, however, an inhabitant of colder regions, being 

 only found in Behring Strait. 



The manatis (Manatus\ of which there appear to be three well-defined 

 species from the tropical coasts of the Atlantic, are chiefly fluviatile creatures, 

 seldom venturing into the ocean, but ascending long distances 

 up the larger rivers, and being especially abundant in the Manatis. 

 Amazon. They grow to a length of about twelve feet, and 

 are heavy, ungainly-looking creatures, with the thick and almost bark-like 

 skin traversed by a number of fine wrinkles. Although in old age the skin 

 may be nearly naked, in early life it is sparsely covered with soft hairs. 

 Externally these animals are specially distinguished by the position of the 

 nostrils at the extremity of the muzzle, the rounded form of the rudder-like 

 tail, -and the usual retention of three rudimental nails on each of the flippers. 

 In the front of the jaws no incisor teeth are visible, although in the young 

 state rudiments exist beneath th0 horny plates investing this region ; but 

 the cheek-teeth, of which eleven pairs are developed in each jaw, are fully 

 developed and approximate in structure to those of the hippopotamus. As 

 a rule, however, only six pairs of the latter teeth are in use at any one time, 

 the anterior ones falling out before those at the hinder end of the series have 

 cut the gums. In the skeleton the extremity of the skull and lower jaw are 

 comparatively short and bub slightly bent downwards, while, as already 

 mentioned, there are only six vertebrae in the neck. 



The triangular muzzle of the manati is remarkable for the circumstance 

 that the extremities of the upper lip are developed into a pair of large fleshy 

 flaps, which can be either brought into apposition with one another or 

 widely separated, so that the animal can, when they are in the former 

 position, seize and retain a leaf between them. Commercially, manatis are 

 valued for their thick hides and the abundant supply of oil yielded by their 

 fat ; and they have in consequence of late years been greatly reduced in 

 numbers. 



The dugong (Hallcore dugong), which ranges from the Red Sea along the 

 Indian and Malayan coasts to Australia, may be distinguished externally 

 from the manatis by the nostrils being situated on the 

 superior aspect of the muzzle, the concave hinder border Dugong. 

 of the tail, and the total disappearance of all traces of nails 

 from the flippers. In the skull the front extremity of both of the upper 

 and lower jaws are extremely massive and deep, with a very marked and 

 sudden downward flexure, while the dentition is of a totally different type 

 from that of the manatis. None of the teeth develop roots, and consequently 

 grow throughout the life of their owner ; the number in the adult condition 

 including a pair of upper incisors and five pairs of cheek-teeth in each jaw. 

 In the males the upper incisors take the form of large downwardly-directed 

 tusks, partially invested with enamel ; but in the female these teeth never 

 pierce the gums. The cheek-teeth, which are quite devoid of enamel, and 



