LUTKA 



357 



length) ; palm bare, a large, heart-shaped, obscurely trilobed 

 tubercular mass behind base of digits, and a round posterior 

 tubercle separated from the larger pad by a deep groove ; sole 

 with a bare area and heart-shaped pad essentially as on palm, 

 but with posterior tubercle represented by an ill-defined prolonga- 

 tion of the main pad ; posterior portion of sole densely furred. 

 Fur very dense and waterproof, alike in texture throughout the 

 body and tail, the hairs of underfur 10 to 15 mm. in length, the 

 longer overlying hairs, which almost completely conceal the 

 underfur, about 25 mm. in length. Mammae : 6* (probably i 3-3). 

 Colour. — Winter pelage : upper parts, legs, feet and tail a 

 rich dark brown (about the prout-brown of Ridgway or some- 



RG. 72. 

 Lutra lutra. Nat. size. 



what darker), with a drabby cast more evident in some lights 

 than in others, the hairs with a conspicuous metallic gloss ; 

 underfur light grey, the extreme tips of its hairs changing 

 abruptly to prout-brown ; on underparts the drab becomes more 

 conspicuous as well as paler, usually assuming a tinge of cream- 

 buff, the throat and cheeks fading to buffy white ; interramial 

 region and upper lip with irregular white mottlings, the hairs of 

 which are white to base ; whiskers and claws light horn-colour. 



The exact colour is subject to considerable variation, but the 

 material examined is not sufficient to show whether such 

 differences as occur are correlated with locality or season. 



* Southwell, Field, en, p. 1043, December 19, 1903. 



