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GEOGRAPHICAL ZOOLOGY. 
[PART IV. 
Remarks on the Distribution of the Chelonia. 
The four families into which the Chelonia are classed have 
all of them a wide distribution, though none are universal. 
The Ethiopian region seems to be the richest, as it possesses 3 
of the four families, while no other region has more than 2 ; 
and it also possesses 7 peculiar genera. Next comes the Neo- 
tropical region with 2 families and 6 peculiar genera; the 
Australian with 3, and the Nearctic with 2 peculiar genera; 
while the Oriental and Palsearetie regions possess none that 
are peculiar. There are about 30 genera and 200 species 
in the whole order. 
Fossil Chelonia . — The earliest undoubted remains of this order 
occur in the Upper Oolite. These belong to the Cheloniidse 
and Emydidae, which are also found in the Chalk. In the 
Tertiary beds Chelonia are more abundant, and the Trionychidae 
now appear. The Testudinidae are first met with in the Miocene 
formation of Europe and the Eocene of North America, the 
most remarkable being the gigantic Colossochelys Atlas of the 
Siwalik Hills. It appears, therefore, that the families of the 
order Chelonia were already specialised in the Secondary period, 
a fact which, together with their more or less aquatic habits, 
sufficiently accounts for their generally wide distribution. 
Species of Testudo, Emys, and Trionyx, are found in the Upper 
Miocene of the south of France. 
