development and life-history, [93], [94];

occurrence, [94];

P. aherniosum, [94];

P. atlanticum, [94];

P. elegans, [94];

P. excelsior, [95];

P. giganteum, [94];

P. minatum, [94];

P. spinosum, [94]

Pyrosomatidae, [91], [81], [110]