rate of growth, [459];

C. cataphractus, [465];

C. intermedius, [466];

C. johnstoni, [466];

C. niloticus = vulgaris, [460] f., [449], [461];

habits, [462] f.;

C. palustris, [449], [454];

skull, [455];

C. porosus, [458];

skull, [458];