CHARACTERS OF SOME SPECIES OF LUTRIN^. 543 



skull appears to me to dijSer from tha.t .of Lutra in characters 

 which by the modern standard must be regarded as of generic 

 value. It is much higher ; the much larger orbit is thrust so far 

 forwards that its anterior rim is above the front edge of jmi. 3, 

 thus greatl}- reducing tlie length of the muzzle, lengthening the 

 floor of the orbit, bringing the frontal postorbital process over 

 the middle of the upper carnassial, and lengthening the area of 

 the cranium between those processes and the " waist." Added 

 to this, the anterior nares are much less sloped, the infraorbital 

 foramen is almost concealed in profile view by its upper bar, and 

 the teeth are out of all proportion larger, etc. 



The long-clawed African Otter (maculicoUis), the type of 

 Gray's genus Ri/droyale, differs from typical Lutra in the reduction 

 of the rhinarium and tiie simplification of the ear ; in the rela- 

 tively large, more fully webbed and hairy-soled feet with reduced 

 plantar pads; and in many cranial characters, especially the 

 shortness of the muzzle, length of the orbital floor, and the 

 generally immature aspect of the skull owing to the feeble 

 development of constrictions, crests, and prominences. 



Since the sum of the differences appear to me to be of generic 

 value, I propose the name nydrictis to replace Gray's twice 

 preoccupied name Hydrogale. 



In defence of the adoption of the name Aonyx for the African 

 small-clawed Otter I need say nothing, since the genus appears to 

 be admitted as valid. 



Tlie Oi-iental small-clawed Otter (cinerea) was nanied Amblonyx 

 by Rafinesque in 1832. By modern writers it has been referred 

 either to Aonyx or to Lutra, despite its differences from both. 

 It resembles Lutra in the rhinarium, facial vibrissa?, and the ear, 

 but differs in the structure of the feet, which are narrower 

 owing to the shorter digits being joined by narrower webs, 

 especially between the second and third and fourth and fifth 

 digits, none of the webs extending beyond the proximal ends of 

 the digital pads. The claws also are short and nearly erect or 

 sometimes, according to Blanford, absent * ; and only the 

 calcaneal a,rea of the hind foot is haiiy. The skull also is veiy 

 different from that of Lutra, and much resembles that of Lutro- 

 gale harang in the character of the muzzle and the size of the 

 teeth, but is altogether much shorter from the frontal postorbital 

 processes and the molars back to the occipital crest and condyles ; 

 the interorbital region is wider, the waist much shorter, and the 

 orbital floor less extensive owing to the shortening of the tooth 

 row. 



In external characters Amblonyx differs from Aonyw, at all 

 events, in the extension of the webbing of the fore feet to the 

 digital pads and in the normal coarseness of the facial vibrissae. 



"* Tlie ahbreviatioii of the claws of the front foot is accompanied in this Otter by 

 extreme delicac}' of tlie sense of touch in this extremity. I have seen one of these 

 animals manipulating- and playino: with a marhle in a manner recalling that of a 

 conjuror juggling with a cricket-hall. 



Proc. Zool. Soc— 195^1, No. XXXVII. 37 



