570 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



of the opening of the pouch, some weeks later, they are grown to 

 a point comparable to the ordinary mammals at birth. 



The marsupials in America are all opossums or rat-like forms but 

 in Australia and Tasmania there are marsupials to represent many 

 of the variations found in the mammals of the world — wolf, bear, 

 squirrel, flying squirrel, cat, marmot, rat, rabbit, lemur, anteater, and 

 mole are all imitated in superficial points of structure and mode of 

 life. 



Marsupials most often seen in collections of living animals are 

 the various species of kangaroos, wallaby, and wallaroo; the 

 phalangers, Tasmanian devil, wombat, and opossums. 



KANGAROOS AND WALLABIES. 



The larger species, the great gray kangaroo (Macropus giganteus), 

 the red kangaroo (M. 7*ufm), and the wallaroo (M. robusfux) natur- 

 ally attract the most attention. They are showy, breed well in 

 capitivity, and the young animals, in and out of the pouch, are a 

 never-ceasing wonder to visitors. From the time when the young are 

 first noted moving in the pouch it is about three months, with these 

 large kangaroos, before the little animal first puts his head out the 

 opening. Then follows a very interesting and amusing few weeks 

 during which the young is in or out of the inarsupium at his pleasure ; 

 sometimes with foot or head out in the most grotesque positions. 

 Finally the mother, concluding that it is time completely to wean 

 her offspring, refuses him further admission to the pouch. These 

 kangaroos sometimes attain a size of over 5 feet for the head and 

 body alone; the added length of the great tail makes the animal 

 appear much larger. 



Several smaller species of kangaroos aie usually kept in the 

 antelope house. Among the most interesting at the present time are 

 the Parma wallaby (Macropus panna), the rufous-bellied wallaby 

 (M. bittardierii) , and the brush-tailed rock kangaroo (Petrogale 

 penicillata). The rock kangaroos are at home in rough country 

 rather than in level areas; the tail is less robust than in the other 

 species and is not used as a ground rest when the animal stands 

 erect. 



The nail-tailed wallaby ( Onychogale frenata) is a small species in 

 which the tip of the tail is armed with a nail-like thorn after the 

 manner of the lion. 



OTHER MARSUPIALS. 



The phalanger (THchosurus vulpecula) is another Australian 

 species, largely nocturnal, and with the habit of playing " 'possum " 

 like its American relative. It is not active in the cages and is 



