The Rio Napo white-browed titi monkey, Callicebus napoleon

Lönnberg described in 1922 a species of white-browed titi monkey that he named Callicebus cupreus napoleon. His description was based on two individuals from the Napo River (Ecuador). According to the author, the animals have a very narrow black, frontal bar and behind the same a broad white, semi lunar band. Behind the latter the crown of the head and the occiput are something between “fawn” and “rust red”, more red in front a little paler on the occiput, where the hairs are rather suddenly lengthened. The back is duller in colour, something between fawn and burnt umber a little more fawn on the rump. On the lower back the paler colour becomes more fawn, and the dark rings are les apparent. Shoulder, sides of the body and thighs grizzled grey by means of whitish and dark brown or blackish rings to the hairs. The flanks are a little overlaid with brownish. Sides of the head, whiskers, throat and entire lower side, inside of limbs, outside of limbs up to elbow and knee, hands and feet, inclusive fingers and toes, most similar to Ridgeway’s “burnt siena” with an inclination to “Sandford’s brown” of the same authors “colour standards” 1912. The base of the tail is grizzled like the flanks with more or less fawn-coloured tips. The greater part of the tail is, however, speckled greyish white and black, because the hairs have long whitish or putty-coloured tips, and below them very broad black rings, the bases being whitish, sometimes with a narrow black ring some distance above the root and separated from the broad sub apical black ring by a white ring. The hairs on top of the ears are whitish, but inside the same and on their lower parts red like the whiskers etc.

Lönnberg ends his description with the remark “if thus all is taken together, the present specimens appear to be easily distinguished from other forms of Callicebus, although the differences are not so very great”. Most other authors indeed consider this species to be a junior synonym of Callicebus leucometopus.