Ostrich, [70].

Otoliths, [74].

Outlines of butterflies' wings, [86].

Owen, Professor, [74], [102], [123], [217], [238], [274].

Oyster of Mediterranean, [88], [98].

Oysters, [79].

P.

Paget, Mr. J., [182].

Palæotherium, [109].

Pallas, [125].