GERARD KREFFT ON DIPROTODON MOLAR TEETH. 317 



19. Remarks on the Working of the Molar Teeth of the Diprotodons. 

 By Gerard Krefft, Esq., F.L.S. &c, Curator and Secretary of 

 the Australian Museum at Sydney, New South Wales. (Read 

 June 24, 1874.) 



(Communicated by the President.) 

 [Abridged.] 



The 'Descriptive and Illustrated Catalogue of the Fossil Organic 

 Remains of Mammalia and Aves exhibited in the Museum of the 

 Royal College of Surgeons of England ' contains, on plate vi., ten 

 figures of the molar teeth of the lower jaw of the extinct gigantic 

 marsupial Pachyderm of Australia (Biprotodon australis), natural 

 size. 



In a subsequent paper, read before the Royal Society, Professor 

 Owen figures the same teeth again (Phil. Trans. 1872, plate xl. figs. 

 1, 5, 9, 12, and figs. 2, 6, and 16), leaving out no. 1, no. V , and no. 

 4' of the Royal College of Surgeons' plate. On plate xxxviii. of the 

 Philosophical Transactions for the year 1872, the same author figures 

 " the outer side view of the right upper molars, in situ, of a large, 

 probably male, Biprotodon ;" also, under no. 1, the grinding surface 

 of the same with part of the bony palate. 



Comparing the upper with the lower series, I have come to the 

 conclusion that the latter cannot be correct, because the whole of 

 the teeth, from first to last, show no sign of abrasion, whilst the 

 upper ones do this in a remarkable degree. The fact is, that when 

 the last tooth breaks through the gum the first of the series is al- 

 ready worn flat, and the premolar is often lost soon afterwards. I 

 desire to point this out, and beg to mention here that I have never 

 seen a series of teeth such as Professor Owen has figured, though 

 many abraded examples with the last molar only half through the 

 bone, and yet already worn, have come under my notice. 



I send a view of such a gradually worn upper series (fig. 1) which 



Pig. 1. — Working Surface of the Premolar and four Molars (the per- 

 fect set) of Diprotodon minor. (About one third nat. size.) 



appears to me to be almost identical with that figured by Professor 

 Huxley in the ' Quart. Journ. Geol. Soc' vol. xviii. pi. xxi. figs. 4 

 and 5. 



