EXTERNAL CHARACTERS OF LUTRA CANADENSIS. 299 



each other and from the main plantar pad. This last is per- 

 fectly naked and papillate for a broadly crescentic space, there 

 being a central furry projection from behind. But the most 

 remarkable feature, peculiar to this species, as far as is known, 

 is the presence of three or four small, definite, circular, elevated 

 papillae, arranged along the posterior border of the naked space. 

 I do not understand these singular structures, the appearance 

 of which almost forces the presumption that they are the excre- 

 tory pores of glandular organs beneath the integument. 



The claws are similar on both fore and hind feet. They are 

 short, stout, compressed, much arched, rapidly contracted from 

 the thick base to an acute point. Those in front are ratlier 

 larger, sharper, and more arched than the hinder ones. 



The fur of the Otter is of great beauty, very thick, close, 

 short, and shining, an exaggeration, in correspondence with the 

 completely aquatic habits of the animal, of that of the Mink or 

 Muskrat. The longer hairs are stout and glistening; the very 

 copious under fur is lanuginous and lustreless. The sheen is 

 only visible in its perfection when the pelt is viewed with the 

 lay of the hairs j from the other direction the color is plain. As 

 in most other species, the color is a rich dark liver-brown, or 

 deep chestnut-brown above, more or less blackish or with a 

 purplish gloss ; paler below, especially anteriorly, on the under 

 parts and sides of the head, the throat, and breast. This pale- 

 ness is very variable, from a slight lightening of the general 

 tone to a pale dull brownish or grayish, or even muddy white. 

 The change is insensible, and there are no special markings 

 anywhere. The roots of the hairs, even on the darkest parts 

 of the pelage, are quite light brown, or often even dingy white, 

 but the fur is so close that this does not appreciably affect the 

 tone of the surface. The top of the tail is ordinarily the darkest 

 part of the animal. The whiskers are partly colorless, partly 

 brown. The nasal pad, palms, and soles are dark-colored. 



Beneath the root of the tail are two glandular eminences. 



Few animals vary more in stature than the Otter. Some 

 individuals are, in round terms, twice as large and heavy as 

 others apparently equally mature, and, at any rate, capable of 

 reproduction. An average total length of full-grown individu- 

 als is 4 to 4J feet ; some specimens, however, touching 5 feet, 

 while others fall short of the first-named dimension. The spe- 

 cies appears to grow several years after puberty. !N^ose to 

 root of tail 3 feet; tail 1 J feet; nose to eye 1^ to 2 inches; nose 



