OTTERS. 



91 



PALATE OF THE CLAWLESS OTTER. 



u PP ermos t tooth on each side is the molar, 



immediately below which is the flesh-tooth. 



portion much expanded. All the species of these animals are thoroughly aquatic 

 in their habits. 



The typical otters, which include all the species except the sea -otter, are 

 characterised by their hind-feet being of normal form, and by the number and 

 structure of their teeth. As a rule, the total number of teeth is 36, of which, on 

 each side of the jaws, f are incisors, \ canines, f premolars, and J molars. The 

 first premolar tooth in the upper jaw is, however, always very small, and in some 

 species (as in the case of the palate here figured) may be totally wanting, thus 

 reducing the number of the teeth to 34. 

 The general characteristics of the teeth of 

 the upper jaw will be apparent from the 

 figure, and it will be seen that the hinder 

 teeth are furnished with a number of sharp 

 cusps, admirably adapted to assist in retain- 

 ing the slippery prey of these animals. In 

 addition to the peculiar characters of the 

 teeth, the skull of an otter may always be 

 recognised at a glance by its extreme con- 

 striction immediately behind the sockets of 



J 



the eyes, and the equally marked expansion 



n -, a IT- c 



ot the flattened brain-case; the portion ot 



the skull forming the face being also very 



short in proportion to the remainder. The tail is thick at the base, and some- 



what flattened from above downwards. In most cases there are short claws 



on all the feet, but in a few species they may be either rudimentary or 



absent. 



In all parts of their organisation otters are admirably adapted for their 

 particular mode of life ; their elongated forms, with but slight constriction at the 

 neck, being perfectly suited to glide through the water with the greatest ease 

 and speed ; their thick, dense fur forming a perfect protection against chill, and 

 their teeth, as we have mentioned, being specially modified in order both to hold 

 such slippery prey as fishes, and at the same time to pierce with facility their hard 

 scales. Probably, in consequence of their precisely similar habits and mode of life, 

 all the otters are so like one another that it is extremely difficult to determine the 

 exact number of species, and scarcely any group has proved more puzzling in this 

 respect to the systematic zoologist. It appears, however, that there are about ten 

 species of true otters, of which one is European and Oriental, three are exclusively 

 Oriental, two are African, and four American. The largest of all is the Brazilian 

 otter, while the two smallest species are the feline otter of South America and the 

 Indian clawless otter. The geographical distribution of the genus is wider than 

 that of any other single Mammalian genus, with the exception of certain bats ; 

 otters having been obtained from all parts of the world except the Antarctic and 

 Arctic regions, Australasia, and Madagascar. We shall allude to the various species 

 of the genus according to their geographical distribution. 



The European otter (L. vulgaris), which is the one represented 

 ' in our coloured Plate, is taken first, as being not only the type of the 



