112 



VERTEBRATES I MAMMALS. 



Fig. 85 A. 



Opossum, D . iiirginiana, 

 Shaw. 



other small animals. The tail is long, prehensile, and 

 nearly naked. More than twenty species are known. In 

 some, the pouch is rudimentary. 



The Genus Didelphys comprises 

 the Common Opossum, D. virginiana, 

 Shaw, of the United States west of the 

 Hudson. It is twenty inches long to 

 the tail, which is about fifteen inches. 

 The hair is whitish with brown tips, im- 

 parting a dusky shade. It lives upon 

 trees, and feeds upon fruits, eggs, and 

 small animals. Its movements are not 

 rapid, and it often lies motionless for 

 hours in the warm sunshine. When 

 captured, or slightly wounded, it has 

 the habit of feigning itself dead, and 

 by this artifice often escapes from the inexperienced hun- 

 ter. The young, which at birth weigh only three or four 

 grains, are placed in the pouch, where they remain grow- 

 ing very rapidly till four or five weeks old, when they 

 begin to venture forth, but for a long time keep close to 

 the mother, generally clinging to her by their tails. 



The Texas Opossum, D. californica, Bennet, is found 

 from Texas westward. 



The Genus Cheironectes is characterized by palmated 

 feet. It is represented by a small species in Brazil. 



The Genus Thylacinus is distinguished from the true 

 Opossums by two incisors less in each jaw, a non-prehen- 

 sile tail, and the absence of a thumb on the hind feet. A 

 species about the size of a wolf, but with shorter legs, is 

 found in Australia. An extinct species has been found 

 imbedded in the plaster quarries of Paris, in France. 



DASYURID^E, OR DASYURUS FAMILY. This Family 

 comprises those which have two incisors and four grind- 

 ers less in each jaw than Opossums, a non-prehensile tail, 



