On the Angwantibo of Old Calabar. 175 



character ; at least, this Angwantibo seems to be somewhat 

 intermediate in its characters between the first two subdivi- 

 sions of the genus Stenops as given by Van der Hoeven, viz. 

 — (a) Tail short ; index of hand very short, resembling an 

 unarmed tubercle ; and — (b) Tail very short. The Ang- 

 wantibo having the index of hand very short, resembling an 

 unarmed tubercle ; and also, the tail very short. To include 

 this animal, the first character of section (a) would require to 

 be altered to — tail short, or very short ; index of hand very 

 short, &c. It seems to me, indeed, from the discovery of this 

 Angwantibo (assuming it to be a new species), that the 

 greater or less length of the tail is not sufficiently distinctive 

 to allow any characters taken simply from it to be used for 

 the division into sections of the comprehensive genus Stenops 

 of Van der Hoeven. 



The generic character which Van der Hoeven gives of the 

 Genus Stenops — index of hand short, not longer than pollex, 

 in the sections (b) and (c), or the equivalent Genera Ny dice- 

 bus, Geoff., and Loris, Geoff. — from the examination I have 

 been able to make of these animals, appears to be due to the 

 smaller relative size of the metacarpal bone, and the phalanges 

 of the index finger, which are three in number, as in all 

 the other fingers (except the thumb). In the Potto, however, 

 and this Angwantibo (as will be afterwards described), which 

 fall under his section (a), and the genus Terodicticus, Benn, 

 the character of index of hand very short, resembling an 

 unarmed tubercle, is due, not only to the small relative size 

 of the bones of that finger, but also to the presence of only 

 two very small phalanges {the same number as in the thumb), 

 the other fingers having three. This anatomical difference 

 forms a good distinction or character between section (a), 

 the Genus Terodicticus, Benn., and the other Genera, which 

 Van der Hoeven has also included in his great Genus 

 Stenops. 



The only species noticed by Van der Hoeven under sec- 

 tion (a) of his genus Stenops, and, as far as I am aware, 

 the only one known, is the Stenops potto or Terodicticus 

 Geofif voyi of Bennett, and it, like this Angwantibo, is a native 

 of Africa ; the other described Genera, or species of Van der 



