146 GIANT EXTINCT FORMS CHAP. 
gonia are represented to-day by a small Marsupial which has 
been rediscovered within the last two or three years. This little 
animal, formerly called Hyracodon (a pre-occupied name), is now 
termed Caenolestes, and is a native of Colombia and Ecuador. 
There are two species, and of these C. obscwrus is called by 
the inhabitants “Raton runcho,’ which means opossum-rat. It 
lives apparently upon bird’s eggs and small birds, though it 
belongs to the Diprotodont division of the Marsupials. Caenolestes, 
however, although diprotodont, has not the syndactylous character 
of the digits of the feet already referred to in the Kangaroos and 
their allies. The pouch is small and rudimentary. The denti- 
tion is 14 C+ Pm 3M4=46, and the teeth are said by Mr. 
Thomas to be much like those of the Australian Dromicia." 
In the skull a peculiarity which does not bear upon its 
affinities to other Marsupials, but is still interesting, is mentioned 
by Mr. Thomas. The nasals are not sufficiently prolonged to 
meet the upper edge of the maxillae, and so a vacuity is left, as 
in the skulls of many Ruminants (e.g. the Sable Antelope). The 
palate 1s very imperfect ; the foramina, which render it so, reach 
as far forward as the last premolar. The lower jaw has quite 
the appearance of that of a Macropus or Phalanger, with long 
and forwardly projecting incisors. 
Extinct Diprotodonts.—The great Diprotodon is a creature 
with a skull a yard long, which must have been of the size of a 
large Rhinoceros. Though closely allied to Macropus, it seems 
that this great beast did not hop after the fashion of a Kangaroo, 
its limbs being of a more equal size than in the Kangaroo. 
Recently some further remains of Diprotodon have been discovered 
in a lake known as Lake Mulligan, where they had apparently 
been bogged. Professor Stirling has contributed an account of 
these remains, which fills up a considerable gap in our knowledge. 
He has been able to state the structure of the fore- and hind-limbs. 
Both limbs are pentadactyle, the fingers of the fore-limb being 
approximately equal in length and general development. In the 
hind-limb the hallux is small, and consists of the metatarsal only. 
This bone is fixed in the position of “extreme abduction,” and is 
suggestive of an arboreal limb. Digits two and three may have 
1 Thomas, ‘‘On Caenolestes, a still existing survivor of the Epanorthidae of 
Ameghino, and the representative of a new family of recent Marsupials,” P.7.S. 
1895, p. 870. 
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