2, eo re >. 
ea 
‘ , ie = 
Th 5! ee 
oy 
a 
“ql 
338 STRATIGRAPHICAL GEOLOGY. [Boox VI. 
later Secondary periods, now cease. The great reptiles, too, which in 
such wonderful variety of type were the dominant animals of the — 
earth’s surface, alike on land and sea, ever since the commencement 
of the Lias, now wane before the increase of the mammalia, which 
advance in augmenting diversity of type until they reach a maximum — 
in variety of form and in bulk just before the cold epoch referred to. 
When that refrigeration passed away and the climate became milder, 
the extraordinary development of mammalian life that preceded it 
is found to have disappeared also, being only feebly represented in 
the living fauna at the head of which man has taken his place. 
Section I.—Eocene. 
§ 1. General Characters. 
Rocks.—In the Old World the most widely distributed deposit 
of this epoch is the nummulitic limestone, which extends from the 
Pyrenees through the Alps, Carpathians, Caucasus, Asia Minor, 
Northern Africa, Persia, Beloochistan, and the Suleiman Mountains, 
and is found in China and Japan. It attains a thickness of 
several thousand feet. In some places it is composed mainly of 
foraminifera (Nummulites and other genera); but it sometimes 
includes a tolerably abundant marine fauna. Here and there it has 
assumed a compact crystalline marble-like structure, and can then 
hardly be distinguished from a Mesozoic or even Paleozoic rock. 
Enormous masses of sandstone occur in the Hastern Alps (Vienna — 
sandstone, Flysch), referred partly to the same age, but seldom con- 
taining any fossils save fucoids (p. 850). The most familiar European 
type of Eocene deposits, however, is that of the Anglo-Parisian and 
F'ranco-Belgian area, where are found numerous thin local beds of 
usually soft and uncompacted clay, marl, sand, and sandstone, with 
hard and soft bands of limestone, containing alternations of marine, 
brackish, and fresh-water strata. | 
Life.—The flora of Eocene time has been abundantly preserved 
on certain horizons. In the English Eocene groups a succession of 
several distinct floras has been observed, those of the London clay 
and Bagshot beds being particularly rich. The plants from the 
London clay indicate a warm climate. They include species of 
palms (Sabal, Nipadites, Fig. 400) and proteaceous plants allied to 
the living Australian Petrophila and Isopogon ; likewise species of 
custard-apple, gourd, melon, almond, oak, walnut, Salisburia, Liquid- 
ambar, Magnolia, Eucalyptus, Bankinia. ‘The remarkable occurrence 
of Australian types in the Lower Eocene vegetation is observable 
also in that of the middle Eocene period, when proteaceous plants 
mingled in the umbrageous forests of evergreen trees —laurels, 
cypresses, and yews. Among the woodlands there grew species of 
ferns (Lygodium, Asplenium, &c.), also of many of our familiar trees 
besides those just mentioned, such as chestnuts, beeches, elms, 
- 
