Pristiurus, [424]

Progress, law of, [19]

Progr"ss, result of, [56]

Pronephros, [389], [397], [419], [424], [449]

Prosencephalon, [48]

Prosoma, [52]

Protopterus, [148]

Protostraca, [27], [396], [417]

Proto"traca, dominance of, [28]

Protozoa, [166], [479]