666 MANUAL OF ZOOLOGY. 



cuspidate, and canines are present (fig. 364, B). The dental 

 formula is 



,-5-5. f ~i. /W 3ZL3 OT 4=4 = 8> 

 3-3 i i 33 44 



The hind-limbs in the Bandicoots are considerable longer than 

 the fore-limbs, and their progression is therefore by a series of 

 bounds. The fore-limbs have really five toes each, but only 

 the central three of these are well developed, the outermost 

 and innermost digits being rudimentary. The three functional 

 toes are armed with long strong claws, with which the Bandi- 

 coots burrow with great ease. The marsupial pouch and 

 this is a singular point opens backwards instead of forwards. 

 In the nearly-allied genus Charopus, also from Australia, the 

 fore-foot has only two functional digits (the 2d and 3d), the 

 ist and 5th digits being wanting, and the 4th being rudimen- 

 tary; while the 4th digit of the hind-foot is the only func- 

 tional toe. 



The second family of this section namely, the true Opos- 

 sums or Didelphidcz is remarkable in being the only group of 

 the whole order which occurs out of the Australian province. 

 The Didelphidce, namely, are exclusively found in North and 

 South America, where they are known as "Opossums." A 

 considerable number of species is known, but they are mostly 

 of small size, the largest measuring not more than from two 

 to three feet, inclusive of the tail. The Virginian Opossum 

 (Didelphys Virginiana) is the only member of the family which 

 is found in North America, and it was the earliest Marsupial 

 known to science ; its place in South America being taken by 

 the widely-distributed Didelphys D'Azara. Most of the Opos- 

 sums are carnivorous, feeding upon small quadrupeds and 

 birds, but they also eat insects, and sometjmes even fruit. 

 One species (Didelphys cancrivora) lives chiefly upon Crabs ; 

 and the Yapock (Cheironectes) has webbed feet, and leads a 

 semi-aquatic life. All the Diddphidce have the hallux nail-less 

 and opposable to the other toes, so as to convert the hind-feet 

 into prehensile hands, and all have a more or less perfectly 

 prehensile tail, these being adaptations to an arboreal life. 

 The marsupial pouch is sometimes not present in a complete 

 form, but is merely represented by cutaneous folds of the 

 abdomen concealing the nipples. In the Didelphys dorsigera, 

 in which this peculiarity obtains, the young soon leave the 

 nipples, and are then carried about on the back of the mother, 

 to whom they cling by twining their prehensile tails round 



