LECTURES ON PALAEONTOLOGY. 
349 
of the expedition published by Sir T. Mitchell in 1838. 
Among these cave fossils Professor Owen had discovered 
remains of the phalanger ( Phalangista ), the wombat ( Phas . 
colomys ), the potoroo [Hypriprymnus) , the kangaroo ( Macro - 
pus), the Dasyurus and Thylacinus . But, although the fossils 
were referable to the foregoing existing genera, they were 
all different from any species now known. Among the 
kangaroos were two species which were much larger than 
the Macropus major; the remains of the Dasyurus were 
larger than those of the D. ursinus, which is now the largest 
living species, and is peculiar to Tasmania. The Thylacinus, 
also, was by this discovery known to have formerly lived in 
Australia, as well as in Tasmania, to which it is now re¬ 
stricted. But, besides the foregoing fossils, there was a 
single tooth, an incisor or tusk of some quadruped, which 
must have equalled a large ox or a rhinoceros in size. In 
this tooth Professor Owen perceived such characters as led 
him to found upon it a new genus, which he termed 
Diprotodon . 
In 1844, Professor Owen received some fossils from Dr. 
Hobson, of Melbourne, which had been discovered in sink¬ 
ing a well at Mount Macedon, near Port Philip. These 
fossils included a portion of the lower jaw, having an inci¬ 
sive tusk in situ, identical in shape and structure with that 
on which the genus Diprotodon had been founded, and also 
molar teeth, resembling in form those of the kangaroo, but 
with generic modifications. This confirmation of the former 
existence in Australia of a gigantic marsupial herbivorous 
quadruped allied to the kangaroo was communicated to the 
British Association, at their meeting in 1844, and was noticed 
in the Annals and Magazine of Natural History for October, 
1844. In the same paper Professor Owen stated that he had 
received from Sir Thomas Mitchell some Australian fossils, 
indicative of a second genus of large marsupial quadrupeds, 
which he described under the name Nototherium. 
Although the molar teeth in both the Diprotodon and 
Nototherium presented the same two-ridged type as in the 
kangaroo, they differed in wanting the smaller connecting 
ridge; and Professor Owen was led to infer, from the struc¬ 
ture of the astragalus and calcaneum (two of the ankle-bones), 
that the hind limbs differed in a greater degree from those of 
the present kangaroos. The above-named tarsal bones had 
been transmitted, with other fossil bones, from Moreton 
Bay, by Sir Thomas Mitchell; they presented marsupial 
characters, and by their size might have belonged to either 
the Diprotodon or Nototherium. In the kangaroos these ankle 
