The details of the ventral scalation were examined in adult and young specimens of seven species of the Malagasy iguanids of the genera Chalarodon Peters, 1854 and Oplurus Cuvier, 1829, both visually and using light microscopy. For the first time, we report data on the topography, morphology and histology of epidermal glandular structures of the genus Oplurus. The modified swollen scales, callous-like in appearance, were described in the abdominal, pre-cloacal and femoral integument. Histological investigation confirmed a presence of the epidermal generation glands of the escutcheon type. In the lizards of the genus Oplurus the epidermal glands are mainly male characteristic, although partially modified ventral scales of the females suggest that they also have a potential capability to production of epidermal gland generation. A biological role of these scales is unclear, as well as their possible relations to lizard's ecology and behaviour.