Pinacocyte, [170], [213], [237]
Pincer-shaped pedicellariae, [456]
Pineau, on spontaneous generation, [43]
Pinnule, of Antedon rosacea, [581], [583];
of A. eschrichtii, [594];
of Hyocrinus, [590];
of Metacrinus, [592];
of fossil Crinoidea, [595]
Pinulus (a pentactine triaxon in which the unpaired actine bears lateral spines and projects beyond the bounding surface), [204]
Piroplasma, [120] f.