INDEX. 
101 
Pentalica, great limestone of the Val di 
Noto seen in the valley of, 64 
Pentland, Mr., on the bones of animals 
from Australian caves, 144 
on the mammiferous remains of 
the Upper Val d'Arno, 220 
Peperino, traversed by dikes near Pala- 
gonia — see diagrams, Nos. 6 and 7, 69 
i dikes of, how formed, 70 
sections of calcareous grit and — see 
diagrams Nos. 9 and 10, 72 
Peperinos, of the Val di Noto, 71 
how formed, 71 
Perpignan, the country between Olot and, 
occasionally shaken by earthquakes. 191 
— fossil shells of — see Tables, Appen- 
dix I. 
Peru, proofs of successive elevation of the 
coast of, 130 
Pewsey, Vale of, 308 ' 
Phillips, Mr., his analysis of chalk flints, 
238 
Philosopher's Tower on Etna, 128 
Phlegrsean Fields, minor cones of the, 125 
Piana, conglomerate of, 211 
Piazza, dip of the tertiary strata at, 74 
Piedmont, tertiary strata of, 20, 211 
their relative age — see diagram, 
No. 4, 21 
Pitchstone, a thin band of, formed at the 
contact of the dikes of Somma and 
intersected beds, 124 
Placentia, character of the sediment 
transported by rivers in the territory of, 
161 
Plants, their fossilization partial, 31 
fossil, importance of, in geology, 47 
Plas Nevvydd, changes caused in sedi. 
mentary strata by a volcanic dike near, 
368 
Plastic clay and sand of the London basin, 
278 
its thickness, composition, &c, 278 
organic remains rare in the, 279 
clay and sand of the Paris basin, 
244 
alternates with calcaire grossier, 244 
Pliny does not mention the Auveigne voU 
canos in his Natural History, 269 
Pliocene period, newer, derivation of the 
term, 53 
proportion of living species in the 
fossil shells of the, 53 
marine formations of the, 62 
, contortions in strata of the, in the 
Isle of Cyclops — see wood-cut, No. 
15, 80 
, strata of the, invaded by lava — see 
wood-cut No. 16, 81 
■ subterranean rocks of fusion, formed 
during the, 107 
— — fresh-water formations of the, 137 
Pliocene period, newer, osseous breccias 
and cave deposits of the, 139 
■ alluviums of the, 145 
extinct animals in breccias of the, 
140 
Pliocene period, older, proportion of living 
species in the fossil shells of the, 54 
• position of the beds referrible to tills 
era — see diagrams Nos. 3 and 4, 20, 21 
mammiferous remains of the, 59 
tertiary formations referrible to the, 
155 
■ volcanic rocks of the, 183 
elevation of land on the East coast 
of England since the commencement of 
the, 316 
Pliocene period, fossil shells of the — see 
Table, Appendix I. 
general results derived from the 
fossil shells of the — Appendix I., p. 47 
number of species of fossil shells 
common to different formations of the — 
Appendix I., p. 47 
number of living species in the fossil 
shells of the — Appendix I., p. 47 
— number of species common to the 
Miocene and — Appendix I., p. 49 
geographical distribution of the 
living species of the — Appendix I,, 
p. 51 
strata of Sicily, their dip and di- 
rection, 73 
Pliocene strata of Sicily, origin of the, 103 
changes of the surface during and 
since their emergence, 109 
strata, newer, only visible in coun- 
tries of earthquakes, 129 
Plomb du Cantal, successive accumulation 
of the, 240 
age of the volcanic rocks of the, 
260, 262 
■ its height, form, structure, &c, 263 
fresh-water limestone covered by 
volcanic rocks on the northern side of 
the, 263 
Plutonic rocks, 353 
distinction between volcanic and, 
359 
their relative age, 364, 377 
changes produced by, 370 
why those now visible are for tha 
most part very ancient, 379 
Podolia, tertiary formations of, 215 
Poggibonsi, conglomerate of, 160 
Pont du Chateau, alternation of volcanic 
tuff and fresh-water limestone at, 258 
Portella di Calanna, furrows in the defile 
called, how formed, 147 
Pratt, Mr., on the mammiferous remains of 
the Isle of Wight, 2S1 
Pressure, effects of, on the consolidation 
of strata, 334 
