THE WEASEL FAMILY 137 



those of the seals leading a similar existence. The specialised 

 molars and general dentition of Latax forbid us to derive either 

 the sea lions or the true seals from the Otter sub-family. The 

 sea otter is a much-specialised member of this sub-family owing 

 to its long, flipper-like hind feet ; otherwise in the rest of the 

 otters the feet are short and rounded, and the toes are webbed. 

 The claws when present are curved and blunt. The head is 

 broad and flattened. The kidneys are specialised in structure. 

 In the teeth, however, the otters are a little more generalised than 

 the remaining groups of the Weasel family in that there are four 

 pairs of premolars in the upper jaw. In the lower jaw there 

 are three pairs, and the true molars are two pairs below and one 

 pair above. The single molar in the upper jaw of the otters 

 is excessively large, and the carnassial fourth premolar is also 

 a tooth of considerable size, with a formidable, three-cusped 

 cutting blade. The first premolar is very small, and often 

 absent in adult otters. 



Lutra vulgaris. The Common Otter 



Besides sharing the general characteristics of the sub-family, 

 the Common Otter may be described as follows : — The full size 

 of the male will measure from the tip of the nose to the root of 

 the tail about 2 ft. 4 in., and the tail would be another i ft. 3 in. 

 The body is long and low, the legs are short and powerful. The 

 upper part of the tail is broad, and flattened horizontally. Under- 

 neath the tail, as in so many of these carnivorous mammals, there 

 are small glands which secrete a fcctid liquid. The muzzle 

 is very broad, and the upper lip thick and overhanging the 

 lower. The vibrissas, or *' whiskers," are thick, almost quill-like. 

 The small eyes are somewhat prominent on the flat head, and are 

 situated not far behind the nostrils. The ears are short and 

 rounded, and pressed close to the nape of the neck. The lower 

 jaw at its base is broad and bulging. The fur, which is of some 

 value, consists of a very fine and soft under-fur of a pale 

 yellowish-gray colour below and brown at the tips. This is set 

 with longer and coarser hair, which is a shining umber-brown 



