XIV INTRODUCTION. 
precipitated, extends across England, from Yorkshire 
on the north-east to Dorsetshire on the south-west, 
with an average breadth of nearly thirty miles; and 
from some land which formed the shore of this arm of 
sea, were washed down the remains of small Insectivo- 
rous and probably Marsupial quadrupeds, distinct in genus 
and species from any now known in the world. With 
these small Mammals there occur elytra of beetles, and 
debris of Cycadee and other terrestrial plants. The cha- 
racter of some of the vegetable fossils and of the as- 
sociated shells, as the Vrigonie for example, and the 
great abundance in the oolitic ocean of fishes, whose nearest 
living analogue is the Port-Jackson Shark (Cestracion), 
recall many of the characteristic features of actual organic 
life in Australia. In contemplating, however, the frail and 
scanty but precious evidence of the ancient oolitic Insecti- 
vora, we naturally ask, could this link of the Mammalian 
chain of Being have existed detached and insulated? Were 
there then no representatives of carnivorous Thylacines 
and Dasyures to enjoy life at the expense of the little 
quick-breeding Phascolotheres and Amphitheres? We can 
searcely resist the latent conviction of such an association, 
notwithstanding the absence of direct proof, since we find 
so many indications of coeval conditions, apparently favour- 
able for the development of all forms of organic life: and 
it is plain, from the scarce and fragmentary parts of the 
skeletons of the hitherto discovered Stonesfield Mammalia, 
that many circumstances concurred to destroy or conceal 
such evidences. 
The non-discovery of the remains of marme Mammalia 
is more conclusive as to their non-existence. Had Whales, 
Grampuses, Porpoises, or Manatees existed in the oolitic 
ocean, it is highly improbable that every trace of their 
