100 OSTEOLOGICAL GALLERY. 



Wombats, which, with but few exceptions, live chiefly upon vegetable 

 food ; to the latter, carnivorous both in structure and habits, the 

 Opossums, Dasyures, and Bandicoots. 



The Kangaroos (Case 24, Div. B) belong to the first group ; 

 their dental formula, when fully developed, being I. f, C. J, Pm. f, 

 M. ^x 2 = 34; some of the anterior grinding-teeth, however, are 

 generally lost before the posterior are in position. The modifications 

 of the bones of the hind feet accompanying their extraordinary 

 " syndactylous " structure has been already referred to (p. 54). 



Skeletons are exhibited of a male and female Red Kangaroo 

 (Macropus rufus) } of a Tree-Kangaroo (Dendrolagus), and a Rat- 

 Kangaroo (Potorous). 



Numerous fossil remains of animals allied to Kangaroos, some 

 as large as a Rhinoceros, have been found in the fluviatile deposits 

 of Australia, among which may be specially mentioned the huge 

 Diprotodon australis, whose head is figured in the Geological 

 Guide, p. 31. 



The Phalangers (Phalangerida) differ from the Kangaroos by 

 the possession of a large opposable hallux, and by the comparative 

 shortness of their hind feet. Their teeth are remarkably variable 

 in form and number, the ten genera of the family being founded 

 almost entirely on these variations. The dental formula ranges 

 from I. f, C. k Pm. f, M. f x 2 = 28, to I. f , C. }, Pm. f, M. , 

 x 2 = 40. In the aberrant Tarsipes rostratus the molar teeth are 

 so reduced and variable that no definite number can be assigned to 

 it. The feet are syndactylous, as in the Kangaroos, but the dis- 

 proportion between the bones of the united second and third toes 

 on the one hand, and the fourth on the other, is not so great as in 

 those animals. 



The Phalangers vary in size from animals as small as a mouse, 

 as for example Acrobates pygmaus, to others larger than a cat, such 

 as the -Koala (Phascolarctus cinereus) . Skeletons are exhibited of 

 the latter animal, of a Cuscus (Phalanger maculatus), and of a 

 Flying Phalanger (Petaurus sciureus). 



The Phascolomyidce, or Wombats, are the only Marsupials with 

 rootless teeth and an equal number of incisors in each jaw, their 

 dentition being I. \, C. , Pm. j, M. f x 2 = 24. The incisors 

 are large and cutting, with the enamel confined to their anterior 



