M 14-16 mm. Similar to B. sarotra but with a granular skin and usually with a vertebral stripe.
Holotype: Adult male, ZFMK 57444, from the forestry station of Manjakatompo, Ankaratra mountains, central Madagascar. SVL 15 mm, head width 4.5 mm; eye diameter 2.3, tympanum diameter 0.8 mm; distance eye-nostril 1.5 mm, distance nostril-tip of snout 1.2 mm; hand length 4 mm, length of foot and tarsus 12 mm; Tibiotarsal articulation reaches slightly beyond eye. Foot is very slightly longer than tibia. Tips of fingers and toes are slightly enlarged. Lateral metatarsalia are separated. Semi-circular femoral glands are present (2.8x1.3 mm, distance from each other 1.6 mm). Each gland consists of 7 large granules. Inner and outer metatarsal tubercle present. Hand without web, foot with a trace of web. Vomerine teeth absent.
Dorsal skin with dispersed, relatively large and distinct tubercles. Back light brown with dark markings, dorsilaterally some of them of longish shape. A distinct yellow vertebral stripe is present. A dark streak, bordered below by white, runs from the eye to the insertion of the forelegs covering the tympanum. Red colour is present on the underside of the tarsus, on the anterior part of the femur, and the insertion of the forelegs. The belly skin is translucent, the silvery belly can be seen through the skin. The underside of the legs is reddish translucent. The granules of the femoral glands are very distinct. The throat is translucent except two silvery white lateral stripes which run parallel to the lips and become visible in calling males during the inflation of the vocal sac. In preservative the colouration has faded, but the vertebral median stripe and the white stripes on the throat are still distinct. The granules on the back are much less distinct than in life.
Other specimens: We observed several more specimens of this same species (about 7) at the type locality. All had a very similar colouration; the vertebral median stripe and, as far as we could observe it, the white stripes on the throat were always present.
Similar species: see M. wittei.
Derivatio nominis: kely (Malagasy) = small.