UPPER MIOCENE OF INDIA. 
227 
proportion of living to extinct mollusca agrees well with the 
usual character of an Upper Miocene or Falunian fauna, as 
observed in Touraine, or in -the basin of Vienna and else¬ 
where. 
The genera of mammalia point in the same direction. One 
of them, of the genus Chalicotherium (or Anisodon of Lar- 
tet), is a pachyderm intermediate between the Rhinoceros 
and Anoplothere^ and characteristic of the Uj)per Miocene 
strata of Eppelsheim, and of the south of France. With it 
occurs also an extinct form of Hippopotamus^ called Hexa- 
protodon^ and a species of Hippotherium and pig, also two 
species of Mastodon^ two of elephant, and three other ele¬ 
phantine proboscidians; none of them agreeing with any fos¬ 
sil forms of Europe, and being intermediate between the gen¬ 
era Elephas and Mastodon, constituting the sub-genus Stego- 
don of Falconer. With these are associated a monkey, al¬ 
lied to the Semnopithecus entellus^ now living in the Himalaya, 
and many ruminants. Among these last, besides the giraffe, 
camel, antelope, stag, and others, we find a remarkable new 
type, the Sivatherium^ like a gigantic four-horned deer. 
There are also new forms of carnivora, both feline and canine, 
the Machairodus among the former, also hyaenas, and a sub- 
ursine form called the Hycenarctos^ and a genus allied to the 
otter {Mihydriodon)^ of formidable size. 
The giraffe, camel, and a large ostrich may be cited as 
proofs that there were formerly extensive plains where now 
a steep chain of hills, with deep ravines, runs for many hun¬ 
dred miles east and west. Among the accompanying reptiles 
are several crocodiles, some of huge dimensions, and one not 
distinguishable, says Dr. Falconer, from a species now living 
in the Ganges ( C. Gangeticus) ; and there is still another sau¬ 
rian which the same anatomist has identified with a species 
now inhabiting India. There was also an extinct species of 
tortoise of gigantic proportions {Colossochelys Atlas)^ the 
curved shell of which was twelve feet three inches long and 
eight feet in diameter, the entire length of the animal being 
estimated at eighteen feet, and its probable height seven feet. 
Numerous fossils of the Siwalik type have also been found • 
in Perim Island, in the Gulf of Cambay, and among these a 
species of Rinotherium^ ^ genus so characteristic of the Up¬ 
per Miocene period in Europe. 
Older Pliocene and Miocene Formations in the United 
States. —Between the Alleghany Mountains, formed of older 
rocks, and the Atlantic, there intervenes, in the United States, 
a low region occupied principally by beds of marl, clay, and 
sand, consisting of the cretaceous and tertiary formation^, 
