The Rufescent white-browed titi monkey, Callicebus subrufus
Elliot described in 1907 a new species of white-browed titi monkey, Callicebus subrufus, from Pachitea on the Ucayali River, Peru.
The species is desribed as having a black face; a narrow black bar on forehead above eyes, succeeded by a broader one of white; rest of head on top, neck, and entire upperparts bright russet, becoming more darker and more reddish on the rumps, the hairs being slate at base, then alternately ringed with slate and bright russet, or on the rump with slate and dark russet or reddish; arms to elbows and thighs to knees grey, the hairs being seal-brown at base, then russet, and tips grey, this colour overlying the rest; hands and feet and rest of limbs bright chestnut-red; sides of face, whiskers, inner side of limbs, throat, chest, and middle of abdomen bright chestnut-red; fingers and toes yellowish grey; tail, basal third black, with chestnut hairs mixed with black at the root, remainder light grey above, whitish beneath; hair on ears white.
The reddish back, white ears and light hairs on the hands may distinguish this species from the other white-browed titi monkeys, but it is generally considered as a synonym of Callicebus leucometopus. Until genetic studies would prove otherwise, we follow this assumption.