Alfred Russel Wallace

“ These extreme modifications and specializations within the range of a single family, are sufficient to indicate the great antiquity of the Australian fauna; and they render it almost certain that the region it occupied was once much more extensive, so as to supply the variety of conditions and the struggle between competing forms of life, which would be required to develop so many curiously modified forms, of which we now probably see only a remnant. ”

“ The Phalangistidæ, or phalangers, are one of the most varied and interesting groups of Marsupials, being modified in a variety of ways for an arboreal life. We have the clumsy-looking tail-less koala, or native sloth; the prehensile-tailed opossum-like phalangers; the beautiful flying oppossums, so closely resembling in form the flying squirrels of North America and India, but often no larger than a mouse; the beautiful dormouse-like Dromiciæ, one species of which is only 21⁄4 inches long or less than the harvest-mouse ”

“ The Echidna, or Australian Hedgehog, although quite as remarkable in internal structure as the Ornithorhynchus, is not so peculiar in external appearance, having very much the aspect of a hedgehog or spiny armadillo. The two species of this genus are very closely allied; one inhabits East and South Australia, the other Tasmania. ”