170 MAB8TTPIALIA. 



foramen ; and the ulna has no distinct olecranal process. The 

 proximal bones of the limbs were apparently placed nearly verti- 

 cally, and appear to have been adapted solely for walking. The 

 feet are only imperfectly known ; but it is probable they were 

 plantigrade and pentadactylate, that the covering of the terminal 

 phalangeals approximated more to the nature of hoofs than claws, 

 and that the phalangeals of the fifth digits were aborted. 



The family apparently connects the Notoiheriidte with the Pha- 

 langistidiv. The absence of a pit and perforation in the masseteric 

 fossa of the mandible is a character common to the three families ; 

 the limb-bones (especially in the fore limb) are nearest to those of 

 the PJialangistidce (the absence of an entepicondylar foramen to the 

 humerus being a peculiar feature) ; while the first upper incisors 

 approximate to those of the Phascolomyidce, more especially to those 

 referred to Phascolonus. The calcaneum and astragalus also ap- 

 proximate to the corresponding bones of the same two families, and 

 are totally unlike those of the Macropodidce. 



Genus DIPROTODON, Owen *. 



Since this is the only known genus, its characters are the same 

 as those of the family. 



Diprotodon australis, Owen 2 . 



This is the type and only species. The largest individuals appear 

 of larger bulk than Rhinoceros unicornis ; but others were consider- 

 ably smaller, although not presenting any structural differences 

 which can be regarded as of specific value. 



Hdb. Australia. 



32851. The nearly entire cranium ; said to have been obtained 

 (Fig.) from the Pleistocene at Gowrie, near Drayton, Darling 

 Downs, Queensland. This specimen (woodcut, fig. 27) is 

 figured by Owen in the Phil. Trans.' 1870, pi. xxxv. 

 figs. 14, and also in the ' Extinct Mammals of Australia,' 

 frontispiece and pi. xix. figs. 1-4. Purchased. 



32869. Fragment of the occipital region, showing the foramen 

 magnum and condyles ; from Australia. Purchased. 



50080. The palatal region of the cranium, showing all the teeth 



1 In Mitchell's ' Three Expeditions into Eastern Australia,' 2nd ed. vol. ii. 

 p. 362 (1838). a Loc. cit. 



