728 ALOUATTA. AOTINyE. AOTUS. 



ISLAND OF COIBA HOWLER. 



Type locality. Coiba Island, off west coast of Panama. 



Genl. Char. Similar to A. palliata, but smaller; zygomata pro- 

 portionally more expanded. A small insular race. 



Color. Like A. palliata. 



Measurements. Head and body, 560; tail, 580; foot, 130. Skull: 

 greatest length, 104.5; basal length, 86.5 ; zygomatic breadth, 79.5; 

 nasals, median length, 15.3; anterior width, 13.5; least width, 7.5; 

 interorbital breadth, n; palatal length, 53; length of upper tooth 

 row (molars and premolars), 33; condyle to angle of mandible, 62; 

 antero-posterior diameter of ascending ramus, 30. 



Subfam. II. Aotinse. Squirrel Monkeys. 



Size small; tail non-prehensile; muzzle not prominent; habits 

 nocturnal. 



175. *Aotus. 



Aotus Humboldt, Recueil d'obs. Zool. et Anat. Comp., i, 1811, p. 

 358. Type Simia trivirgata Humboldt. 



Nyctipithecus Spix, Sim. et Vesp. Bras., 1823, p. 25. 



Head round; orbits large; nasal septum narrow; nostrils approxi- 

 mate. 



FIG. 165. AOTUS AZAR/E. 

 No. 37793. Coll. U. S Nat. Mus. Nat. size. 



*To illustrate this genus, no skull of a Central American species being 

 available, that of a South American species is given. 



