THE SEA OTTER. 



2C1 



In the Margined-tailed Otter* the skull characters, which we have mentioned as distinctive of 

 Ottei-s, especially the narrowness of the region between the eyes, and the shortness of the nasal 

 region, are so exaggerated, that the animal approaches towards the Sea Otter, of which we shall speak 



next. The Margined-tailed Otter, which is 

 found in Brazil and Surinam, derives its name 

 from a longitudinal ridge on each side of its 

 conical tail. The fur is of a bright bay-brown 

 colour, both above and below. 



SIDE VIEW OF SKULL OF SEA OTTER. (After Coues.) 



THE SEA OTTER.t 



This interesting animal differs in many 

 important respects from the Common Otter, 

 and in all such points shows an approxima- 

 tion to the structure of the Seals. It is a large 

 animal, about three feet long, not counting 

 the tail, which is about a foot more. Its fur 

 is dark brown, both on the upper and lower 



surfaces, and presents a frosted or silvered appearance, owing to the fact that the long stiff hairs, 

 which differ greatly from those of the under-fur, are grey or colourless at the tip. The head is 

 very short, the snout naked ; the eyes extremely small, and placed low down on the sides of the head, 

 and the whiskers are short, but stout and stiff, and mostly directed downwards ; altogether there is 

 something very Seal-like about the face. The fore-limbs and feet are small, the paws rather Cat-like in 

 their rounded form, and the claws are quite hidden by the hair. The hind feet, on the other hand, 

 are flat and expanded, being no less than six inches long by four broad, and webbed like a Duck's feet, 

 or a Seal's flippers ; they differ, however, from the Seal's, in the fact that the toes increase in length from 

 the inner to the outer side ; both above and below they are covered with dense fur, which quite hides the 

 short, stout claws. The skull is, both in its cranial and facial portions, much shorter in comparison 

 with its width than in the ordinary Otters ; its base is extremely broad, and both upper and lower 

 jaws bear on each side only eight teeth, so that there are altogether thirty-two teeth, or four less 

 than in the Common Otter. J This diminution in number is brought about, as will be seen from the 

 formula below, by reducing the upper premolars from four to three, and the lower incisors from three 

 to two on each side. The form of the grinders 

 differs altogether from what we have found, not 

 only in the Mustelidse, but in all the Land Car- 

 nivores. Their grinding surfaces present no 

 sharp cusps, or jagged cutting edges, as in most 

 Carnivorous forms ; neither are they provided 

 with numerous small tubercles and ridges, as in 

 the Bears ; but the surface of each is raised 

 into a small number of rounded eminences, re- 

 minding one of the " roches moutonn^es " of a 

 glacial district, or, as Dr. Coues remarks, dif- 

 fering from the teeth of ordinary Carnivores, 

 as water-worn pebbles differ from fresh-chipped 

 angular pieces of roclc. 



The Sea Otter is found in the North Pa- 

 cific, chiefly in the regions of Kamstchatka and 

 Alaska, and extends as far south as California. 



Like the Seal, the Sea Otter is gregarious, being often found " in bands numbering from fifty 

 up to hundreds. When in rapid movement, they make alternate undulating leaps out of the water, 



UNDER VIEW OF SKULL OF SEA OTTER. (After Coues.) 



75 



* Pter&nura Sandbachii. t Enhydra lutris. 



J Dental ." -rmula Incisors, |r| ; canines, jl, ; premolars, 3^3} molars, 2 -2~ 



