Diagnosis.This is a medium-sized species distinguished externally from other species of Caenolestes by its grizzled brownish gray dorsum; its venter is cream-colored to pale grayish and lacks a pectoral spot. Ventral hairs are gray-based with light tips. The tail is noticeably bicolored with a very dark dorsum and warmer, drab brown venter. The tail is densely covered with short hairs that obscure the scales. The skull is medium-sized (Figs. 3A, 4A, and 5A). The antorbital vacuity is narrow to moderately open, ranging from crescent- to comma-shaped and is bounded by the maxillary and nasal bones (Fig. 4A; Supporting Information S2, DOI: 10.1644/13-MAMM-A-018.S2). The canine is medium to long, ranging from 2.7 to 3.1 mm in adult males and is slender and curved, most strongly near the tip of the tooth (Fig. 3A). The incisive foramen is slightly curved, especially at its anterior margin (Fig. 5A). The major palatine foramen is large and wide. The ventral-median lip of the foramen magnum has a U-shaped indentation between the left and right occipital condyles. The posterior margin of the postpalatine torus is curved and delicate. There is a diastema between 14 and the canine.