AMERICAN DIPROTODONTS 



129 



is one strong pair, with occasionally one or two rudimentary incisors. 



ejct.aud. 



NiJ 



Fig. 63. — Skull of Wombat {Phascohnnys ivombat). (Lateral view.) ang, Angular pro- 

 cess ; cond, condyle of mandiljle ; ext.and, opening of bony auditory meatus ; 

 ex.oc, exoccipital ; ju, jugal ; Icr, lachrymal ; max, maxilla ; nas, nasal ; p.max, 

 premaxilla ; sq, squamosal ; tij, tympanic. (From Parker and Haswell's Zoology.) 



The upper canines, if present, are not large. The molars are 

 tuberculate or ridged. All Marsupials (ex- 

 cept the Wombats) to some extent, and the 

 Macropods especially, are characterised by 

 the prolongation of the tubes of the dentine 

 into the clear enamel. The significance of 

 this fact is, however, lessened by the fact 

 that the same penetration of the enamel 

 by dentinal tubes occurs in the Jerboa, the 

 Hyrax, and some Shrews. The feet have 

 two syndactylous toes,^ less marked in the 

 Wombats than in the Kangaroos and 

 Phalangers. 



This order is mainly Australian at the 

 present day, using the term of course in 

 the "regional" sense (see p. 84); the only 

 exception indeed to this statement is the 

 occurrence of the genus Caenolestes in South 

 America. But it is now known that Dipro- 

 todont Marsupials formerly existed in the 

 same part of the world. 



Fam. 1. Macropodidae. — This family 

 contains the Kangaroos, Wallabies, Eat- 

 Kangaroos, and Tree-Kangaroos. With the exception of Dendro- 

 ' Exce])t in the South American Diprotodonts. 

 VOL. X K 



Fig. 64. — Bones of right 

 foot of Kangaroo (Macro- 

 jms bennetti). e, Astra- 

 galus ; c, calcaneum ; 

 cb, cuboid ; e^, ento- cu- 

 neiform ; n, navicular ; 

 //- V, second to fifth toes. 

 (From Flower's Osteology.) 



