Figure 4. – A-B in Comparative morphology of the finlet spines of the extant Polypteridae (Osteichthyes; Cladistia). Systematic interest

Figure 4. – A-B: Polypterus bichir katangae; A: The anterior face of the spine is covered by an irregular ganoine layer, and shows the basal articular head (AH) and the shaft (SH); B: The posterior face of the spine shows, the median groove and the basal foramen on the shaft; the two arrow-heads indicate the two lateral pads. C-F: P. senegalus; detail of the anterior (C), the posterior (D), the left lateral (E), and the basal face (F) of the articular head, respectively, to show the various significant processes; the arrowhead points to the median groove (F). Scale bars: A, B = 1 mm; C-F = 0.5 mm.