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THE ANIMALS 01 THE UNITED STATES 



restricted to America, although they are nearly related to the Australian family 

 Dasyuridoe. Opossums are distinguished by a clawless opposable first toe on the 

 hind-foot, which thus serves as a hand, by the long tail being generally hairless, 

 scaly, and prehensile, and by the incisor teeth comprising five pairs in the upper 

 and three in the lower jaw. 



A few years ago only a single species of opossum (Didelphys marsupialis) 

 was recognised in the United States; but the one inhabiting north-western Mexico 

 adjacent to California is now regarded as distinct, under the name of D. californica. 

 Typically the common opossum is about as large as a cat, attaining a length of over 



18 inches with 

 i a tail about an 

 1 inch shorter. In 

 colour it displays 

 considerable 

 variation, some 

 forms being 

 white, others 

 black, and others 

 of almost every 

 int er m ediate 

 hue. In districts 

 where it is very 

 common it not 

 only lives in 

 forests, but is 

 found in towns, 

 where it shelters 

 in drain-pipes and other hiding-places dur- 

 ing the day, and pays unwelcome visits to 

 fowl-houses at night. Besides birds and 

 other small animals, it feeds on eggs, roots, 

 and fruit, and more or less everything 

 eatable, even carcases. On account of its 

 pilferings. it is much persecuted; it has 

 great vitality and is an adept at feign- 

 ing death, as is exemplified by the many 

 amusing stories told about opossums believed to be dead which afterwards 



escaped. 



Comino- to the birds of the United States, mention may first be 

 perching Birds. ^^ rf ^ distinct , y America n group of bluebirds, the best known 

 representative of which is the so-called blue robin (Sialia sialis). Somewhat larger 

 than a redbreast, this species is sky-blue above, and chiefly chestnut below. It 

 ranges from southern Canada to the Gulf of Mexico, and is one of the most popular 

 birds in the United States, owing to its graceful movements and pleasing song. 

 The true thrushes have numerous North American representatives ; and in another 

 family mention may be made of the beautiful ruby-throat. Among the wrens are 



OPOSSUM. 



