are now becoming fossil, 745.
----, mineralization of, 747.

Plants, fossil, of the coal strata, 87, 115, 133.

Plastic clay fossils, 142.

Plastic force, fossil shell ascribed to, 20.

Playfair on Huttonian theory, 53, 57.
----, on instability of the earth's surface, 212.
----, on gradual rise of Sweden, 523.
----, on form of the earth, 534.

Plieninger, Professor, on triassic mammifer, 137.

Pliny the Elder, 16.
----, on delta of Rhone, 258.
----, on Islands at the mouth of the Texel, 329.
----, killed by eruption of Vesuvius, A. D. 79, 364.

Pliny the Younger, on Vesuvius, 364.

Pliocene strata, fossils of, 143.

Plot on organic remains, 26.

Pluche, theory of, 1732, 83.

Plutonic rocks, how formed, 161.
----, action, changes produced by, 176, 178.

Po, R., 207.
----, frequently shifts to course, 255.
----, embankment of the, 256.
----, delta of the, 256, 284.
----, subsidence in delta of, 257.

Poisson, M., on astronomical causes of changes in climate, 127.

Polyps. _See_ Zoophytes.

Pomerania, fossil ships in, 758.

Pompeii, how destroyed, 365, 385, 387.
----, section of the mass enveloping, 386.
----, objects preserved in, 390.
----, infusorial beds covering it, 388.

Pont Gibaud, gneiss decomposed at, 248.
----, calcareous springs near, 239.

Poole Bay cut into by sea, 319.

Popayan, volcanoes and earthquakes in, 349.

Portland, fossil ammonites of, 28.
----, its peninsula wasting. 319.

Port Royal, subsidence of, 504, 517, 691, 762.

Porto Praya, Azores, calcareous stratum, 436.

Portugal, earthquakes in, 358.

Porzio on formation of Monte Nuovo, 369, 371.

Post-tertiary formations, 184.

Precession of the equinoxes, 100, 537.

Prentice, Lieut, on coral reef in Maldives, 778.

Pressure, effects of, 171.

Prestwich, Mr., on artesian wells, 234.

Prevost Const., on Stonefield fossil mammalia, 138.
----, Const., on gypseous springs, 245.
----, on rents formed by upheaval, 371.
----, on new island in Mediterranean, 433.
----, on geological causes, 718.
----, on osseous breccias of caves, 736.

Prevost, Pierre, on radiation of heat, 93.

Prevost, Mr. J. L., on number of wrecked vessels, 756.

Primary fossiliferous rocks, fossils of, 114.

Priscodelphinus, cetacean, of chalk, 145.

Pritchard, Dr., on Egyptian cosmogony, 8.
----, on recent origin of