DESCRIPTION' OF A EING-TAILED OPOSSUM — WAITE. 93 



mm. 



Teeth, horizontal length of -^- ... ... 1-5 



,, height of Canine ... ... ... 2 "3 



length of P^ 3-2 



length of Mi-3 11-4 



,, diastema of J^ and C. ... ... 3 -7 



C.&ndP' 2-8 



P^andP-^ 1-0 



,, length of lower -? ^ ... ... ... 98 



It is interesting to notice that the structure of the tail corres- 

 ponds with the habits of the animals ; thus, in /'. 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, De Vis,* of which we 

 hold co-types from the describer, exhibits none of the characters 

 here sought to be emphasised, and except in the markings does 

 not differ from typical examples of P. herbertensis, as previously 

 determined. 



The nest or DREY op the RING-TAILED OPOSSUM, 

 (PSEUDOCHIRUS PEREGRINUS, BODDj. 



By Edgar R. Watte, F.L.S., Zoologist. 

 (Plate xix.) 



One of the most peculiar and interesting habits of the Ring-tailed 

 Opossum ( PseiidocMrus 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. 



