PROFESSOR OWEN ON THE FOSSIL MAMMALS OF AUSTRALIA. 
263 
assailant the Machairodus neogceus, although, as in the Anteater, the habitual service 
of the claws may have related to insects or vegetable diet. 
One is guided in a conjecture as to the uses of claws by the evidence afforded by the 
associated fossils of the animals which, if unguiculate, would have had claw-bones of the 
size of those under consideration. 
No evidence of a Megatherioid or other Edentate animal has been had from any cave 
or fossiliferous deposit in Australia. The shape of the ungual phalanges in Kangaroos 
and Wombats is known. The ungual phalanges (Plate XIII. figs. 12-14) are too small 
for Nototherium and Diprotodon , if even one were to entertain the idea of those huge 
Marsupial Herbivora having had sheathed, compressed, decurved, pointed claws, like 
those which the plalanges in question plainly bore. These phalanges are as much too 
large for the Thylacinus and Sarcophilus. But there is no other associated Carnivore 
corresponding in size with that of the animal indicated by them, save the Thylacoleo. 
It is open to any one to repeat, with respect to these phalanges, the remark which 
has been made on the fossil metacarpal of the carnivorous type from Australia, the size 
of which is such, as the articular surfaces ( a in figs. 11, 12 & 13, Plate XIII.) show 
to have entered into the formation of the paw terminated by such claw-phalanges, viz. 
“That the metacarpal bone figured in Phil. Trans. 1859, Plate xm. belonged to the 
same animal as the skull is only conjectural”*. 
All that has been above advanced in searching out the nature of the ungual phalanges 
made known to me by photography is conjectural ; but if a Paleontologist or Compa- 
rative Anatomist is willing to lend friendly aid in such difficult gropings after the things 
of the past, he should point out in what particulars he deems the grounds of the con- 
jecture to be defective. 
A great proportion of the fair edifice of Paleontology still rests upon a scaffolding of 
wise and well-founded “ conjecture.” 
Description of the Plates. 
PLATE XI. 
Fig. 1. Portion of right upper jaw-bone ( maxilla ) and teeth, outer side view. 
Fig. 2. Portion of right upper jaw-bone (maxilla) and teeth, inner side view. 
Fig. 3. Portion of right upper jaw-bone ( maxilla ) and teeth, under view with working- 
surface of teeth : the relative size and position of the tubercular is shown at 
m i. 
Fig. 4. Portion of right upper jaw-bone ( maxilla ) and teeth, front view. 
Fig. 5. Portion of right upper jaw-bone ( maxilla ) and teeth, hind view. 
fig. 6. Crown of a less worn upper laniary (i i), outer side; from a breccia-cave. 
* XII. p. 309. 
MDCCCLXXI. 2 O 
