48 On Two new Species of Potto. 



affording moans ol" comparison. Tliislar;j;e Gaboon spccios i.^ 

 cliaracterizod by its long head, short tail, and dull greyish 

 colouring. 



The genus Arctocehiis is well separated from Perodicticns 

 in the t'onnation of the hand, the fuller development of the 

 mclars, the want of the shelf over the auditory meatus formed 

 by the squamosal, and the absence of the protruding processes 

 ot tiie cervical vertebra?. 



Perodicticns Batesi, sp. n. 



Size intermediate between P. potto and P. Edwardsi. 

 Colour very much richer and more rufous or almost red- 

 mahogany. Bristle-Lairs about nape strongly developed. 

 Tail very short, as short or shorter than that of P. Edioardsi. 



Type in the British Museum, no. 9S. 5. 4. 12, ? , 11th Feb., 

 1898. Benito lliver, 15 miles from mouth. CJ. L. Bates, 



no. :uo. 



Fang name " Awun." 



Measurements (taken in the flesh) : — 



Head and body 380 millim. ; tail 40; hind foot 75; 

 ear 23. 



Another specimen (a male) has practically the same 

 measurements. 



'ihe skull, except in being larger, closely resembles that of 

 P. potto; the squamosal portion of the zygomatic arch is, 

 however, broader, and the teeth are larger. 



The skull of P. Edicardsi is very readily distinguished by 

 its length and less expanded zygouiata, and at the same time 

 by tiie great breadth of the posterior portion across the 

 mastoids and auditory bulla3. 



Arctocehus aureus^ sp. n. 



Size smaller than A. caliharensis ; tail very short, the 

 terminal iiairs stiff and closely pressed together. 



The whole of the upper surface bright golden red, the hair 

 very lustrous, with no dark tips ; the lower side is dull and 

 paler, niixed with ashy grey. 



The snuut is considerably projected beyond the lower lip. 

 The front of the face, from the eyes to the point of the nose, 

 is sparsely clothed with minute hairs and is practically 

 naked ; from the side of the nose to the eyes there is a slight 

 ridge of stiffer hairs, with a few longer sensory hairs inter- 

 sj)ersed, the fur on the cheek growing forwards to assist in 

 the formation of the rid^e. Tiie immediate circle of the orbit 



