Periblast, [471]
Peripatus, [396], [399], [400], [411], [421], [429]
Petromyzon, alimentary canal, [405], [445]
Petro"mzon, auditory organ, [378]
Petro"mzon, branchial segments, [169]
Petro"mzon, life-history, [59]
Petro"mzon, olfactory tube, [219], [226]
Petro"mzon, pronephric duct, [402]
Petro"mzon, retina and optic nerve, [95]
Petro"mzon, skeleton, [125]