FIGURE 2. Heads of species of Anchylorhynchus. Scale: 500 µm. A A. centrosquamatus, male, showing five well-defined dorsal carinae in the rostrum and scales on the head directed to the interocular fovea. B A. centrosquamatus, male, showing the pairs of lateral carinae along the scrobe, totaling 7 carinae in the rostrum. C A. pinocchio, female, showing five dorsal carinae poorly defined towards the base. D A. pinocchio, female, showing the lateral carinae poorly defined towards the base. E A. aegrotus, showing scales in the head smaller and directed to the base of the head. F A. burmeisteri, showing scales in the head directed to the rostrum. G A. tricarinatus, male, showing three well-defined dorsal carinae. H A. tricarinatus, male, showing no lateral carinae. I A. bicarinatus, male, with three well-defined dorsal carinae. H A. bicarinatus, male, with only two dorsal carinae and no central carina.