DESCRIPTION OF A RING-TAILED OPOSSUM — WAITE. 
93 
Teeth, horizontal length of l 2 
„ height of Canine ... 
,, length of -P 4 
,, length of .M -1 ' 3 
„ diastema of 1 :i and C. 
C. and P 1 
„ „ P l andP s 
„ length of lower 1 1 ... 
1*5 
2*3 
32 
11-4 
3*7 
2-8 
1*0 
98 
It is interesting to notice that the structure of the tail corres- 
ponds with the habits of the animals ; thus, in P. herbertensis , 
which ascends the highest trees, the lower surface is naked for a 
greater portion of its length and is roughened so as to afford a 
secure grip of the topmost wind-swayed branches. In its more 
lowly habit, P. colletti avoids such positions, and has therefore 
less need of special adaptation. 
It may be mentioned that P. mongon , Dc Vis,* of which we 
hold co-types from the describes exhibits none of the characters 
here sought to be emphasised, and except in the markings does 
not dilfer from typical examples of P. herbertensis , as previously 
determined. 
The NEST or DREY of the RING-TAILED OPOSSUM, 
(PSEUDOCIIIRUS PEREGRINUS , BODDJ. 
By Edgar R. Waite, F.L.S., Zoologist. 
(Plate xix.) 
One of the most peculiar and interesting habits of the Ring-tailed 
Opossum ( Pseudockirus peregrinus , Bodd), is that of making a 
nest or drey. Although well-known, but little appears to have 
been written on the subject beyond the notice that it is not unlike 
that of the European Squirrel. 
I as often found the drey of this latter animal in a hole in a 
tree as among the branches, a situation never utilised by the 
Opossum. The nest of the Marsupial may be constructed either 
in a fork or upon a platform of interlaced twigs. A thick bush 
is more favoured than a tree, but almost any growth, if sufficiently 
dense, may be made use of : the Lilly Pilly ( Eugenia), offers a 
congenial retreat, as does also the Tea Tree ( Melaleuca ), its long 
strips of loose bark being frequently woven into the nest. The 
native “Oaks” (Casuarina), and the Wattles (Acacia), are further 
favourites. Preference is shown for the neighbourhood of water. 
* De Vis— Proc. Linn. Soc. N.S. Wales (2) i., 1887, p. 1130. 
