_, 24

Pigs, origin of, 44-46

Pika, 41

Pine-Grosbeak, 191

_Pinicola enucleator_, 191

_Planorbis dilatatus_, 24
_glaber_, 167

Plants, American, in Ireland, 166
as tests of climate, 75-80
migration of, 34

_Platyarthrus_, 299-302

_Plectrophenax nivalis_, 140

Pleistocene climate of Asia, 210, 214-215
Europe, climate in, 208-209
fauna, northern and southern animals in, 72-75
mollusca, 211-213

Pliocene deposits of Sicily, 277
geography, 276-277

Pohlig, H., 176

Polar Bear, 134
Fox, range of, 135, 149
origin of animals, 147

Pole-cat, 190

_Polydesmus gallicus_, 115, 302

Polynesian Islands, 20

_Pomatias_, 49, 321-322

_Pontoporeia affinis_, 179

Porto Santo, molluscan fauna of, 25

Pouched Marmot, 41

Praeger, R. L., 298

Praying insect, 269

_Proboscidea_, origin of, 252

_Psammodromus algirus_, 295
_hispanicus_, 295

Ptarmigan, 91, 142

_Pupa_, antiquity of, 50

_Pupa_, 297-298
_anglica_, 298
_granum_, 297
_ringens_, 102

_Pyrrhocorax alpinus_, 317

_Pyrrhula_, 191, 255
_europaea_, 191, 256
_major_, 191, 256

Rabbit, introduction of, 27, 31, 291

_Rana temporaria_, 194, 320

Range, extension of, 38

_Rangifer tarandus_, 133, 150-158

Reade, Mellard, 127-129

Red Crag, Arctic molluscs in, 235-236

Red Deer, 246-250

Red Grouse, 91, 142

Red-legged Partridge, 29

_Regulus ignicapillus_, 257
_maderensis_, 257
_teneriffae_, 257

Reid, Clement, 76, 163

Reindeer, range and varieties of, 91, 133, 149-158

Relict lakes, 176-179, 223

Reptiles, dispersal of, 21

Reptiles of Europe, 192-193

_Rhax_, 270

Rhinoceros, distribution of, 214-216

_Rhododendron ponticum_, 271

_Rhopalomesites Tardyi_, 302

Rock Sparrow, 318

Route of migration of Siberian mammals, 210

_Rupicapra tragus_, 312

Russia, marine transgression in, 172
submergence of North, 155

Ruetimeyer, L., 43, 57, 281

_Ryothemis_, 269

Saiga Antelope, 39, 204

_Saiga tartarica_, 39, 204

_Salamandra atra_, 319
_caucasica_, 319
_maculosa_, 319

_Salmonidae_, origin of, 92, 143

Sandgrouse, migration of Pallas's, 41, 205

Sars, O., 177, 223-224

Saunders, H., 256

Seal, Arctic, 174

Sea-urchin, 125

Sedgwick, A., 86

Scandinavia, absence of Orien