Ptychoceras Emericianum, [486].

Ptychodus gibberulus, [578].

--------- polygurus, [594].

--------- spectabilis, [578], [585].

Pulley-stones, [285].

Purbeck. See [Isle of Purbeck].

------- marble, [422], [435].

------- series, [26].

Purfleet, [317], [843].

Pustulopora pustulosa, [268], [270].