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Suborder DIPROTODONTIA. 



Section Poephaga. 



Family GRAVIGRADA. 



Genus Dipeotodon. 



Species Biprotodon australis. 

 § 1. Introduction. — In a letter dated May 8th, 1838, addressed to Sir Thomas Mitchell, 

 F.G.S., Surveyor-General of Australia, giving results of an examination of a series of 

 Fossil Remains from caves in ' Wellington Valley,' and published in his ' Three Expe- 

 ditions into the Interior of Eastern Australia,' vol. ii. 8vo, 1838, one of the specimens 

 was described as follows : — 



" Genus Diprotodox. I apply this name to the genus of Mammalia, represented by 

 the anterior extremity of the right ramus, lower jaw, with a single large procumbent 

 incisor (IX.), fig. 1, pi. 31. This is the specimen conjectured to have belonged to the 

 Dugong, but the incisor resembles the corresponding tooth of the Wombat in its ena- 

 melled structure and position (see fig. 2, pi. 31, and a section of the Wombat's teeth in 

 fig. 7, pi. 30). It differs, however, in the quadrilateral figure of its transverse section, 

 in which it corresponds with the inferior incisors of the Hippopotamus. To this Bipro- 

 todon, or to some distinct species of equal size, have belonged the fragments of bones of 

 extremities marked X, X a, X b " (p. 362). 



I reproduce the original figures (Woodcut, figs. 1 & 1 a) representing the specimen of 

 half the natural size, and the section of the Fig. i. 



incisor of the full size, on which the genus was 

 founded ; but which specimen I now know to 

 be that of a young individual. 



Extraordinary as seemed the magnitude of 

 the beast which this tooth indicated, at a 

 period when the largest known mammal of 

 Australia was a Kangaroo, it gave only half the 

 size of the full-grown Biprotodon australis. 



In ignorance of this fact I was led astray 

 by the first evidences (femur and molar teeth) 

 of the mature animal which were transmitted to me from freshwater deposits in another 

 and remote locality of Australia ; and, for a short time, I believed them to belong to a 

 Proboscidian, referring them, in 1843, on the authority of a drawing of part of a jaw 

 and teeth transmitted to me by Sir Thomas Mitchell, to the Dinotherian section of 

 that order*. 



* Annals and Magazine of Natural History, No. 71, for May 1843. 



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