534 CENOZOIC TIME — MAMMALIAN AGE. 



an elevation of 3000 feet in a part of the island of Sicily (p. 523). 

 Thus, throughout the Tertiary period, the continent was making 

 progress in its bolder features over the surface, as well as in the 

 extent of dry land ; and the evidence is sufficient to show that 

 when the period ended, the continents had their mountains raised 

 in general to their full height. 



3. Climate. — The climate of North America during the Early 

 Tertiary is fully indicated by the abundant fossil plants of the Lig- 

 nite beds. Among the genera mentioned on p. 514, Sapindus, Pla- 

 nera, Cinnamomum, Ficus, and Sabal belong to a warm climate ; and 

 taken in connection with the other genera they indicate a mean 

 atmospheric temperature near that of the Dismal Swamp in North 

 Carolina. (A. Gray.) This corresponds to the warm-temperate zone, 

 and to the year-isothermal of 60° F. This isothermal in the West 

 passes through Fort Smith (near the meridian of 94° W.) on the 

 Arkansas Eiver, and terminates on the Pacific near Los Angeles, 

 after a long and narrow northward bend in California nearly to the 

 Shasta Peak. Plants of these kinds were growing together in the 

 Eocene forests of the Upper Missouri, where now runs the isother- 

 mal of 45°, — a line which passes close by the north shore of Lake 

 Ontario, down the St. Lawrence to Montreal, then south through 

 Vermont and east through southern Vermont and New Hampshire 

 to Portland, Me. It follows thence that the climate along this 

 line was warm-temperate. 



Brandon, Vermont, is upon the line, and, in accordance with the 

 fact, the plants of the Lignite (p. 510) include Sapindus, Cinnamomum, 

 and Illicium, indicating about the same temperature, and confirming 

 the view that the Brandon and Upper Missouri species belong to 

 the same part of the Tertiary. 



With regard to the plants of the later Tertiary, little is known. 

 The animals of the Pliocene in the Upper Missouri region include 

 Camels and other kinds characteristic of the warm-temperate zone ; 

 so that there is no sufficient evidence that the climate was cooler 

 than in the Eocene. 



Europe evidently passed through a series of changes in its cli- 

 mate from tropical to temperate. According to von Ettingshausen, 

 the Eocene flora of the Tyrol indicates a temperature between 74° 

 and 81° F. and the species are largely Australian in character. 

 The numerous palms at the same period in England correspond to 

 a climate but little cooler. 



The Miocene flora of the vicinity of Vienna the same author pro- 

 nounces to be subtropical, or to correspond to a temperature between 

 68° and 79° F, ; it most resembles that of subtropical America. 



