In two females examined in 2011, the Junin slender opossum had a russet back and a white strip down the middle of the belly. Additional records are from Junín, Peru.
The two females examined had dark markings around the eyes, a russet midline on the back, cinnamon sides, and a white strip along the middle of the belly.
The two animals collected in 2011 were caught in traps set on the ground. Study sites included primary-growth forest and plots growing coffee or bananas.
In the two females collected in 2011, the upper surfaces of the wrists and ankles bore hairs white to their bases, without a strong colour contrast with the digits.
Of the two females collected at San Antonio in July 2011, the young adult weighed 17 g and measured 224 mm in total length, including a 130-mm tail; the adult weighed 27 g and measured 242 mm in total length, including a 137-mm tail.
An extinction-risk assessment has not been added yet.