COMMUNITY OF STRUCTURE. 61 



Wild Cats; no Edentata, neither Sloths, nor Tatous, nor 

 Ant-Eaters, nor Pangolins ; no Pachyderms, neither Ele- 

 phants, nor Hippopotamuses, nor Hogs, nor Rhinoceroses, 

 nor Tapirs, nor Wild Horses; no Ruminantia, neither 

 Camels, nor Llamas, nor Deer, nor Goats, nor Sheep, nor 

 Bulls, etc.; and yet the Mammalia of Australia are almost 

 as diversified as those of any other continent. In the 

 words of Waterhouse, 1 who has studied them with parti- 

 cular care, " the Marsupialia present a remarkable diver- 

 sity of structure, containing herbivorous, carnivorous and 

 insectivorous species ; indeed, we find amongst the Mar- 

 supial animals analogous representations of most of the 

 other orders of Mammalia. The Quadrumana are repre- 

 sented by the Phalaugers, the Carnivora by the Dasyuri, 

 the Insectivora by the small Phascogales, the Ruminantia 

 by the Kangaroos, and the Edentata by the Monotremes. 

 The Cheiroptera are not represented by any known Mar- 

 supial animals, and the Rodents are represented by a single 

 species only. The hiatus is filled up, however, in both 

 cases, by placenta! species ; for Bats and Rodents are tole- 

 rably numerous in Australia ; and, if we except the Dog, 

 which, it is probable, has been introduced by man, these 

 are the only placenta! Mammalia found in that conti- 

 nent." Nevertheless, all these animals have in common 

 some most striking anatomical characters, which distin- 

 guish them from all other Mammalia, and stamp them as 

 one of the most natural groups of that class. Their mode 

 of reproduction, and the connection of the young with the 

 mother, are different; so also is the structure of their 



brain, etc. 2 



Now, the suggestion that such peculiarities could be 



1 WATERHOUSE (G. A.), Natural pialia' in Todd's Cyclopaedia of Anat. 

 History of the Mammalia; London, and Physiol.; London, 1841, 8vo.; 

 1848, 2 vols. Svo., vol. i, p. 4. and several elaborate papers by him- 



2 See OWEN (R.), article ' Marsu- self and others, quoted there. 



