26 ALLEN'S NATURALIST'S LIBRARY. 



THE POTTOS. GENUS PERODICTICUS. 



Perodicticus, Bennett, P. Z. S., 1839, p. 109; Huxley, P. Z. S., 



1864, p. 235. 

 Arctocebns, Gray, P. Z. S., 1863, p. 150 ; Mivart, P.Z.S., 1864. 



p. 644. 



This genus contains two species, both confined to the 

 West Coast of Africa. The Pottos are slender-bodied ani- 

 mals, with oval heads and blunt Dog-shaped muzzles. Their 

 eyes are large and full, and their external ears erect, with 

 shelf-like lamellae inside. They have slender and sub-equal 

 limbs. The second digit of the fore-limb is rudimentary and 

 nail-less; it is supported on one wrist-bone, and has two 

 phalanges or finger-bones. The great toe is opposable, and 

 the fourth and fifth digits of both limbs are united together 

 by membrane as far as the first joint. The processes of the 

 vertebrae in the neck and back are long and protruding. The 

 tail is very short. 



The pre-maxillse (which carry the incisor teeth) do not project 

 in front, nor does the bony palate extend farther back than the 

 end of the posterior molar teeth. Of the upper teeth the 

 incisors are equal in size (Fig. 6) ; the median and posterior 

 pre-molars have on their crowns three cusps, of which the two 

 outer are the larger ; the anterior and median molars are cin- 

 gulate, have four-cusped crowns, and are larger than the pre- 

 molars ; the posterior is narrow from before backwards, and its 

 crown presents only two or three cusps. Of the lower teeth, the 

 anterior pre-molar is recurved and larger than the canine, with a 

 ridge on its inner face and a cusped heel behind ; the median 

 and posterior ones are shorter than their anterior fellow, each 

 having a strong posterior cusped heel; the anterior and median 



