THE OPOSSUMS. 193 
directly, and, as soon as it had got a fair start, it progressed 
with great rapidity.” 
What becomes of the Ur-quamata during the cold season, 
when, according to native reports, it is no more seen above 
ground, has not yet been ascertained. From the circumstance 
that during a slight frost two specimens kept in a box of sand 
died, it may, however, be inferred that during the winter these 
little creatures must burrow to such a depth in the sand as to 
be beyond the reach of the slight frosts met with in the 
districts they inhabit, and that in such burrows they undergo a 
more or less complete hibernation. No sort of information 
has hitherto been ascertained as to the breeding habits of these 
little creatures, a young one not even having been seen. 
It may be added, in conclusion, that there is no sort of sup- 
port to the suggestion that the Marsupial Mole forms a con- 
necting link between the Marsupials and the egg-laying 
Mammals. Among the former it is believed by Dr. Gadow to 
be more nearly related to the Opossums than to either of the 
other Australian families of Polyprotodonts. 
LHe OPOSSUMS. FAMILY DIDELPHYIDA‘. 
With the Marsupial Mole we take leave of the Australian 
representatives of the order, and come to the single American 
family, which includes the whole of the remaining forms now 
living. Possessing the characters already given as distinctive of 
the Polyprotodont sub-division of the order, the Opossums 
_ may be characterised as a family as follows :— 
Five pairs of upper, and three of lower incisor teeth. Hind 
feet with the four outer toes subequal and detached, and a 
_ well-developed, although clawless, inner toe, or hallux, which 
can be opposed to the other four. Tail generally very long, 
_naked, scaly, and prehensile, but occasionally short and more 
| or less hairy. Stomach simple ; intestine with a small or 
2 Q 
