'Stokes' presumably refers to the Commander of H.M.S. Bloodhound. The faces of all three Nigerians show the characteristic tribal marks, three short parallel cuts, sometimes straight, sometimes crescent, on the cheeks. The practice of male and female circumcision, noted on the first drawing, was thoroughly discussed by Burton in many of his books.
He comments on the varied local costume on his return downstream from Wari: 'It is a constant mortification in these lands, the hideousness of one's so called fellow-creature. They must also deform deformity by their barbarous hankering after the cast-off finery of Europe: Royal Marines' swallowtails, beadles' great-coats, and the sky blue tiles of masquerade. What a contrast to the picturesque and beautiful costumes of Asia - the turban, the haik, and the burnus!' (My Wanderings in West Africa, p. 157)