2 8o POUCHED MAMMALS. 



are about the size of a mouse, after which they venture abroad, although return- 

 ing to its shelter for the purpose of being suckled or sheltering for a considerable 

 time. The female exhibits the most marked attachment to her offspring, and 

 endeavours by every means in her power to prevent her pouch from being opened. 

 Rat-Tailed The rat-tailed opossum (D. rmdicaudata) is a well-known 



opossum. representative of the second group of the genus, which includes 

 three medium-sized species, characterised by their short, close fur being of one 

 kind only, and their long tails, which in two of the species are naked, although in 

 the thick-tailed opossum (D. crass! en In fa) the tail is hairy nearly to its tip. 

 Although in the two species above-named the pouch is rudimental or absent, it is 

 well-developed in the Quica opossum (Z). opossv/ni). 



Philander The philander (D. philander) and the woolly opossum 



Opossum. (£. lanigera) are easily distinguished from the members of the 

 preceding group by the presence of a distinct brown streak running down the 

 middle of the face. The pouch is represented merely by two longitudinal folds of 

 skin. The philander attains a length of from 9h to Hi inches to the root of the 

 tail; the tail itself varying from 12| to 15 inches. The fur is thick, soft, and 

 woolly, and of a dull yellowish or rufous grey colour, with the face pale grey, save 

 for the dark brown streak down the forehead, and similar dark areas round the 

 eyes ; the under-parts being some shade of yellow. This species is restricted to 

 Guiana and Brazil, but is replaced in most other parts of tropical South America 

 by the somewhat larger woolly opossum. In both species, the young, which may 

 be a dozen in number, are carried on the back of the mother, ami it is marvellous 

 with what rapidity the females when thus loaded manage to climb trees. 



The murine opossum (D. mv/rvna), ranging from Central Mexico 

 Murine Opossum. x ° ° 



to Brazil, may be taken as an example of the fourth group of the 



genus, in which all the species are small, with short, close hair, very long tails, and 

 no dark streak down the middle of the face. The pouch is absent in all the group 

 In size the murine opossum may be compared to a common mouse ; the general 

 colour of its fur being bright red. From their small size it may be inferred that 

 all the opossums of this group live exclusively upon insects. 

 Three-striped The last group of the genus includes its smallest representatives, 



opossum. among which the three-striped opossum (D. americana) of Brazil is 

 conspicuous for its coloration. The whole ten species which constitute this group 

 are shrew-like little creatures, easily recognised by their short and generally non- 

 prehensile tails, which are less than half the length of the head and body. The 

 three-striped species, which is by no means the smallest, measures from 4£ to 5^ 

 inches to the root of the tail : while the length of the tail is rather less than 

 2i inches. Its general colour is reddish grey, with three black bands running 

 down the back. Another species (D. ivnistriata) has a single dark line down the 

 back ; but in nearly all the others the colour is uniform. The smallest of all is 

 the shrew-opossum (D. sorex), from Kio Grande do Sul, in which the length of the 

 head and body is less than 3 inches. 



The water-opossum or yapock (Chironectes minima) differs from 



all the other members of the family in having the hind-toes webbed, 



and the presence of a large tubercle on the outer side of each fore-foot, giving the 



