MARTENS, POLECATS, AND WEASELS. I05 



Otters, and their allies, differs widely both from the Felidce 

 and the Caiiidce. in the structure of the base of the hinder 

 part of the skull. In place of the bladder-like and rounded 

 auditory bulla characterising the two latter groups, in the 

 present family this portion of the skull is depressed, with no 

 dividing partition, its inner border being the most prominent, 

 and thence it gradually slopes away towards the tube conduct- 

 ing to the internal ear, of which tube the lower lip is prolonged. 

 The intestine is devoid of any blind appendage (caecum) ; and 

 the toes are always five in number on each foot. 



The present Family is specially distinguished from others, 

 in which the above features occur, by the following points: 

 The upper molar teeth are reduced to a single pair, which are 

 peculiar in that their inner border is wider than the outer; 

 while (with the exception of the Indian and African Ratels, 

 where they are reduced to one) there are two pairs of molar teeth, 

 the first of which is the flesh-tooth. The number of pre-molar 

 teeth is very variable, even within the limits of a single genus. 



Having, with the exception of Australasia, a world-wide 

 distribution, the members of this Family present none of that 

 external similarity of form so characteristic of the repre- 

 sentatives of the two preceding families ; and they exhibit a 

 similar diversity of habit ; some, like the Martens and Weasels, 

 being more or less fitted fur climbing, while others, like the 

 Badgers, are burrowing animals, and others, again, like the 

 I Otters, aquatic. 



MARTENS, POLECATS, AND WEASELS. GENUS MUSTELA. 

 Mustela, Linn., Syst. Nat. ed. 12 vol. i. p. 66 (1766). 



The members of this genus, together with certain allied 

 forms which are generally separated and have no representa- 

 tives in the British Isles, collectively constitute a special sub- 

 family of the Musielidx. Terrestrial and more or less arboreal 



