. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. REVISION OF THE GENUS COLOPHON GRAY 377 7. Dorsal process of mandible present to absent. 8. Ventral process of mandible in basal, to median or apical position. 9. Lateral margin of pronotum moderately to sharply and deeply emarginate posteriorly. 10. Gena evenly rounded behind eye to a distinct postgenal Fig. 8. Simple female mandibular structure in Colophon westwoodi Gray. The mandibles are very similar in females of all Colophon species. Where applicable, the very uniform display of
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. REVISION OF THE GENUS COLOPHON GRAY 377 7. Dorsal process of mandible present to absent. 8. Ventral process of mandible in basal, to median or apical position. 9. Lateral margin of pronotum moderately to sharply and deeply emarginate posteriorly. 10. Gena evenly rounded behind eye to a distinct postgenal Fig. 8. Simple female mandibular structure in Colophon westwoodi Gray. The mandibles are very similar in females of all Colophon species. Where applicable, the very uniform display of character states in females was used for out-group comparison in deciding on the polarity of the transformation series. Females generally, but notably in Lucanidae, are more conservative in phenetic changes and thus can be considered in most characters to be close to a hypothetical ancestor (Figs 8, 14A). In some other characters, stages uniformly displayed by the symmetrical-aedeagus lineage, were considered as plesiomorphic states in the genus, the presence of an apico-ventral process of the anterior tibia and the presence of a dorsal process of the mandible. The synapomorphies, as displayed in the plesiomorphic and in the apo- morphic lineages of species respectively, are shown in Figures 6 and 7. From these data a cladogram was constructed (Fig. 9). On the branches the numbers of synapomorphies are marked in squares and the numbers of autapomorphies in circles, indicating the position of terminal species. THE PRESENT-DAY DISTRIBUTION OF COLOPHON SPECIES COMPARED WITH THEIR EVOLUTION It is assumed that Colophon, as a monophyletic genus, had a single ancestral specie:,. From this ancestral population, by the repeated speciation of marginal population fragments, an increasing number of species has evolved. In a slow- moving, wingless and terrestrial type of organism such as Colophon, the process of dispersion must have been slow and the chances of population fragmentation
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