200 CAENIYORA. 



* Genus Lutra, Linn. 



Dr. Gray, in the Catalogue of Carnivorous Mammalia/ separates Enhydris 

 lutris, or the Sea Otter, as a distinct tribe from the true Otters, under the name 

 JEnhydrina. The Lutrina or true Otters he refers to two groups depending on the 

 character of their tails ; the first having the tail rounded on the sides, and the second 

 having the tail with a cord-like ridge on each side. The first of the groups is 

 broken up into genera, viz., Barangia, Lontra^ Lutra, Nutria, Lutronectes, Aonyx, 

 Hydrogale, and Latax ; and the second group contains only the genus Pteronura. 

 These first eight genera are again referred to sub- divisions : one, including the 

 first six genera, is said to be distinguished by the palms and soles of the feet being 

 bald between the pads, and the palm pads, without any small circular warts on 

 their hinder edges ; the other, which includes the last two genera, has the under 

 surface of the feet, between the finger pads and palms, sprinkled with scattered, soft 

 hairs, and the inner part of the under surface of the two inner hind toes with a 

 band of close, short, soft hairs. In some of the animals of the first group, the nose 

 is clothed with hair, while in others it is bald, which is also the character of the 

 nose of the animals of the second group. 



The ridge-like cord on the tail of Fteronura, Gray, or JPterura of Wiegmann,^ 

 is of a doubtful nature, and is not a sufi6.cient character to give the animal generic 

 rank, as the tails of other Otters are not rounded, but have sharp margins ; and Dr. 

 Gray seems ultimately to have allowed this. The cranium and teeth also exactly 

 conform to the true Lutrine type, the only remarkable feature of the skull being its 

 great size ; but other Otters — e. g., Lutra inunguis and Lutra braziliensis — are quite 

 as remarkable in this respect. 



On examining the feet of the Otters referred by Gray to the secondary sub- 

 division of the Lutrina, I observe that the greater number were characterised by the 

 presence of scattered small hairs on the under surface of the webs, so that the 

 absence or presence of scattered hairs on the palms and soles must be abandoned as 

 a means of separating the genera. 



The sub-division of the first of the two primary groups is again sub-divided 

 into two minor groups, the first distinguished by its hairy, and the second by its 

 bald nose. But the first of these is subjected to a further sub-division, in which 

 the nose is said to be perfectly hairy in one, and partially bald in the other. To the 

 haky sub-division the genus Bai^angia is referred, but I observe that the nose 

 of the type of this genus is not perfectly clad, as the centre between the nostrils 

 is bare, and Cantor mentions that the hair becomes partially rubbed off with age ; 

 but in a full-grown animal in the India Museum, London, the nose is still 

 hairy. 



Before adverting to these genera more particularly, it may be stated that the 

 teeth of all exhibit a remarkable conformity of structure, and that they do not offer, 



» Cat. Carniv. &c., B. M. 1869, pp. 100-118. » Archiv. fur Naturgesch. 1838, p. 392, pi. 10. 



