194 MARSUPIAL WATER TRESPASSERS. 



Like most aquatic animals of small size, it resides 

 in burrows which it digs in the bank, the opening 

 being beneath the surface of the water. 



In this remarkable animal we see, therefore, a most 

 instructive instance of the manner in which a compara- 

 tively slight modification of structure can transform an 

 arboreal into an aquatic animal, and enable it to live 

 with completely changed habits. Instead of traversing 

 trees, it swims and dives through the water. It seeks 

 its prey in the river, and not on the shore ; and, in- 

 stead of making its home, as the terrestrial opossums 

 do, in the hollow of a tree, or even usurping that of a 

 squirrel or some other animal that makes a warm and 

 snug nest, it excavates for itself a burrow in the bank 

 of the river, just after the fashion of the common 

 water rat of our own country. 



Before leaving the marsupials, I should like to say 

 a few words upon another marsupial trespasser, 

 although it trespasses in another direction. Assuming 

 the monkeys to be the type of arboreal animals, we 

 have the remarkable fact that by very slight modifica- 

 tions of structure, an essentially terrestrial marsupial 

 animal becomes changed into an arboreal trespasser. 

 We have already seen how the arboreal opossum can 

 take an aquatic form, and we shall now see how the 

 kangaroo itself can become arboreal. 



I allude to the famous Tree Kangaroo (Dendrologus 

 ursinus). This very remarkable animal has the fore 

 paws much longer, and the hind legs much shorter, 

 than is the case with those species which have only to 

 traverse the ground. The black claws are peculiarly 

 long and rather curved. 



