Pigment in the skin, [34]
Pipa, [143], [144], [149] f., [150]
Pit-Vipers, [644]
Placodontia, [311]
Placodus, [301];
P. gigas, [311]
Plastron, of Chelonia, [315], [321], [321];
provided with hinges, [323];
sexual characters of, [331];
movable in Emys, [350];