28 FAUNA ANTIQUA SIYALENSIS. 



characters of the middle and older tertiaries of Europe. That 

 they belong to the vertebrate series which immediately preceded 

 the existing race of animals ishardlysnsceptibleof doubt from 

 the admixtiire of existing reptUes.^ * * # And as changes of the 

 fossil fauna of Euroj)e, which mark the different subdivisions of 

 the tertiary series, have been shown to have been coincident 

 with changes of climate, and repeated elevations and depres- 

 sions of temperature — if we can only show that the climate of 

 India has been less subject to great oscillations during the 

 tertiary period, and that the surface of the land enjoyed longer 

 periods of repose, it would be, perhaps, not unj)hilosophical 

 to conceive that the epoch of the Sewalik fauna may have 

 lasted throxigh a period corresponding to more than one of 

 the tertiary periods of Europe. 



D. 



GEOLOGICAL AND CLIIIATAL BEAEINGS OF THE SEWALIK FAUNA. 



Besides the mere zoological interest of the subject, the 

 Sewalik inquiries involve these conclusions. 



1. The upheavement of a narrow belt of the plains of India 

 at the foot of the Himalayahs into hills 3,500 ft. high along 11° 

 of longitude, or about 800 miles, after the long estabUshment 

 on the continent of such modern forms as quadrumana, camel, 

 giraffe, and existing species of reptilia. 



2. A great upheavement of the Himalayahs, extending to 

 many thousand feet, and equal to the elevation of a tract 

 which formerly bore a tropical fauna, up to a height which 

 now causes a climate of nearly arctic severity. Remains of 

 rhinoceros, antelope, hysena, horse, large ruminants, &c., found 

 at 16,000 feet above the sea.^ 



3. Conditions in India during the tertiary period precisely 

 the reverse of what have held in Europe. Instead of a suc- 

 cession of periods with successive decrease of temperature, 

 India has now as high a temperature, if not higher, than it 

 ever had during the tertiary period. The upheavements have 

 operated to increase the heat. In lat. 30°, at 7,000 feet above 

 the sea, the mean temperature, making the compensation for 

 the elevation, and reducing it to the level of the sea, is 8 1*2° 

 Fahr., or equal to that of the equator. The same excess of 

 temperature holds generally over the continent, as contrasted 

 with the eastern side of the continent of Asia. 



4. Instead of numerous subdivisions of the tertiary jDcriod 

 with successive faunas, facts tend to the conclusion that India 

 had one long term, and one protracted fauna, which lived 



' Manuscript defective. — [Ed.] 



^ On this matter, see furtlier the memoir on The Fossil Ehinoceros of Tibet. — 

 [Ed]. 



