INTRODUCTION. 59 



mals." Mr. Bennett's * opinion is next quoted, that 

 author having strongly expressed his belief that the 

 Marsupalia do not form a natural group. '' When 

 we see/' observes Mr. Bennett, " that the single pe- 

 culiarity that unites them, is bestowed upon types of 

 form so widely different from each other, we cannot 

 consider this simple metastasis of junction in a certain 

 set of organs alone, however great the importance of 

 that function in the animal economy, as furnishing 

 sufficient ground for the overthrow of every principle 

 of classification, and for setting at nought some of the 

 most strongly marked affinities that the animal king- 

 dom affords." 



In the classification of Illiger, the greater portion 

 of the Marsujnata are thrown together_, and constitute 

 the sixth family of his order PoUicata; but the Kan- 

 garoos and Hi/pspri/mni are separated from the rest, 

 and form a family by themselves, to which he applies 

 the name Salientia. 



By Storr, those Marsupial animals, which have a 

 distinct opposable thumb — the true Opossums and 

 Phalangers — are placed near the Quadrumana, and 

 form the third division of a great group, the first of 

 the divisions consisting of the genus Homo, and the 

 second being composed of the Monkeys and Lemurs. 



Mr. Ogilby,t also considering the presence of an 



* The Gardens and Menagerie of the Zoological Society 

 Delineated, vol. i., p. 265. London, 1831. 



+ Observations on the Opposable Power of the Thumb 

 in certain Mammalia, considered as a Zoological Character, 

 &c. &c. Magazine of Natural History, vol. i., p. 449, and 

 p. 517. 



