CONTENTS. j x 



— Fluctuations of climate in Post-glacial period — Comparative longevity of 

 species in the mammalia and testacea — Teeth of recent and Post-pliocene mam- 

 malia, ---..- . p AGE 107 



Chapter XI. — Post-pliocene Period, continued — Glacial Epoch. 



Geographical distribution, form, and characters of glacial drift — Fundamental rocks, 

 polished, grooved, and scratched — Abrading and striating action of glaciers — 

 Moraines, erratic blocks, and "Roches Moutonnees ''—-Alpine blocks on the Jura 

 — Colossal size of ancient Swiss glaciers — Continental ice of Greenland — Ancient 

 centres of the dispersion of erratics — Transportation of drift by floating ice- 

 bergs — Bed of the sea furrowed and polished by the running aground of floating 

 ice-islands — How to distinguish glacial drift of submarine from that of terrestrial 

 origin, - - - - - - - - - 136 



Gsapter XII. — Post-pliocene Period, continued — Glacial Epoch, concluded. 



Glaciation of Scandinavia and Russia — Glaciation of Scotland — Marine shells in 

 Scotch glacial drift — Their Arctic character — Rarity of organic remains in 

 glacial deposits — Contorted strata in drift — Glaciation of Wales, England, and 

 Ireland — Marine shells of Moel Trjfaen — Norfolk drift — Glacial formations of 

 North America — How far of submarine origin — Many species of testacea and 

 quadrupeds survived the glacial cold — Connection of the predominance of lakes 

 with glacial action — Morainic lakes — Objections to the hypothesis of the erosion 

 of large lake-basins by ice — Conversion of valleys of denudation into lakes by 

 upward and downward movements — Action of ice in preventing the silting-up 

 of lake-basins — How the bed of a sea where icebergs have abounded may, on 

 emergence, afford lake-basins — General causes of change of climate — Submer- 

 gence of the Sahara in the Post-pliocene period a cause of Alpine cold — Meteor- 

 ites in drift, -....._. 149 



Chapter XJII. — Classification of Tertiary Formations.- — Pliocene Period. 



Order of succession of sedimentary formations — Imperfection of the record — Defec- 

 tiveness and obscurity of the monuments greater in proportion to their antiquity 

 — Reasons for studying the newer groups first — General principles of classifica- 

 tion of tertiary strata — Detached formations scattered over Europe — Strata of 

 Paris and London — More modern groups — Peculiar difficulties in determining the 

 chronology of tertiary formations — Increasing proportion of living species of 

 shells in strata of newer origin — Eocene, Miocene, and Pliocene terms explained 

 — Formations of the Newer Pliocene period — Island of Ischia — Eastern base of 

 Mount Etna — Newer Pliocene strata of great height and extent in Sicily — For- 

 mations of same age in the Upper Val d'Arno — Norwich Crag — Chillesford 

 beds — Bridlington beds — Older Pliocene strata — Red Crag of Suffolk — White 

 or coralline Crag — Successive refrigeration of climate proved by the pliocene 

 shells of Suffolk and Norfolk — Antwerp Crag — Subapennine strata — Aralo-Cas- 

 pian formations, - - - - - - - - 178 



Chapter XIV. — Miocene Period. 



Upper Miocene strata of France — Faluns of Touraine — Depth of sea and littoral 

 character of fauna — Tropical climate implied by the testacea — Proportion of 

 recent species of shells — Faluns more ancient than the Suffolk Crag — Varieties 

 of Voluta Lamberti peculiar to Faluns and to Suffolk Crag — The same spe- 

 cies are common to more than one geological Period — Lower Miocene strata 

 of France — Remarks on classification, and where to draw the line of separation 



