758 THE. MAMMOTH CAVE AND ITS INHABITANTS. 
were inhabited by postpliocene mammalia and shells. The caves 
of Anguilla include remains of twelve vertebrates,* of which seven 
are mammalia of extinct species, and several of them are of large 
size. These are associated with two recent species of molluses 
Turbo pica, and a Tudora near pupeformis.; As these large ani- 
mals no doubt required a more extended territory for their support 
than that represented by the small island Anguilla, there is every 
probability that the separation of these islands took place at a 
late period of time and probably subsequent to the spread of the 
postpliocene fauna over North America.” 
I think the reader will conclude from the facts Prof. Cope so 
clearly presents, that the subterranean fauna of this country does 
not date back of the Quaternary period. These species must have 
been created and taken up their abode in these caves (Mammoth 
Cave and those of Montgomery County, Virginia) after the breccia 
flooring their bottoms and containing the bones of Quaternary ani- 
mals had been deposited; or else migrated from Tertiary caves 
farther south, which is not probable, as it has been previously 
Shown that those blind animals inhabiting wells immediately die 
on being exposed to the light. (British Sessile-eyed Crustacea, i, 
p. 313.) 
The case becomes much simpler when we consider the age of 
the rocks in which the Adelsberg and other caves mentioned by 
Schiddte are situated. The Alps were under water in the Middle 
Eocene ; consequently the caves could not have been formed until 
the close of the Tertiary. Hence the species of the cave fauna 
were evidently created either at the close of the Tertiary, or more 
probably the beginning of the Quaternary, as “even in the later 
part of the Pliocene era there was an elevation of three thousand 
feet in a part of the Island of Sicily” (Dana). We are therefore 
led to conclude that the species of the subterranean fauna the 
world over are recent creations, probably not older than the ex- 
tinct mammals associated with man. 
b De Rijgereman which mae A fourth species of gigantic Chinchillid has been found 
which be $ ted b; 
‘A 3 a lus quadr Cope. It is represen 
One: jaws ge teeth of three individual Tris one of the largest species, equa 
; m o pe 
in section; th 
the smallest. 
m. .063 or 2.5 
Con in the outlines of the 
ae oo dwe peak agra approaches the genus Amblyrhiza. 
quadrans, and Amblyrhiza inundata > >S UOWS, 
mer. Phil. Soc., 1871, 58. 
4 
a 
E 
7 
