Paul’s, St., rocks of.
Pearlstone.
Peperino.
Peron, M., on calcareous rocks of Australia.
Phonolite, hills of. -laminated. -with more fusible hornblende.
Pitchstone. -dikes of.
Plants, extinct.
Plutonic rocks, separation of constituent parts of, by gravity.
Porto Praya.
Prevost, M. C., on rarity of great dislocations in volcanic islands.