448 Zoological Society. 



December 14, 1852.— Dr. Gray, F.R.S., Vice-President, in the Chair. 



Notes on the Anatomy of the Tree-Ka.ngar.oo 



(Dendrolagus inustus, Gould). 



By Professor Owen, F.R.S., V.P.Z.S., etc. 



The specimen of the above rare species, the first that had been 

 exhibited alive in Europe, was a full-grown and somewhat aged 

 female, having lived in the Society's Menagerie since the 8th of Oc- 

 tober, 1848. It had suffered from a disease in the tail, for which 

 more than half of that organ had been amputated, and the stump 

 was well-healed. I am not aware what symptoms preceded the ani- 

 mal's death, which took place on the 13th of October, 1852; the 

 dissection did not bring to light any well-marked morbid appear- 

 ances. 



The external characters of the animal have been so well described 

 and illustrated by the learned Dutch naturalists, MM. Miiller and 

 Schlegel, that further remarks on them may be here dispensed with : 

 the chief modifications of the Kangaroo-form which adapt the herbi- 

 vorous marsupials of the present subgenus to their singular sphere of 

 existence, are a reduction of the length of the hind-limbs to a more 

 near equality with the fore-limbs, which are proportionally longer 

 and stronger than in the land Kangaroos : the claws of the principal 

 toes in both limbs are longer, stronger, and more curved than in 

 other Macropodidce ; they are, in fact, the chief instruments enabling 

 the Tree-Kangaroos to maintain a firm hold on the branches of the 

 trees in which they habitually reside. 



As the bones of the animal dissected are still in maceration, any 

 remarks that the osteology of the Dendrolagus may require, will be 

 communicated at a future meeting. 



Before commencing the dissection the weight of the animal was 

 taken, which was 16 lbs. avoirdupois. 



The length of the animal, from the muzzle to the end of the tail, 

 was 2 feet 1 inch ; the length of the head was 4 inches 9 lines ; the 

 length of the fore-limb, from the head of the humerus, was 1 2 inches ; 

 that of the hind-limb, from the head of the femur, 1 foot 6' inches. 



The dental formula was : — i y^y, c ^, p ~, m jzi~ 30- The 

 canines, confined as above indicated, to the upper jaw, were much 

 smaller than in the Potoroos, indicative of a closer affinity to the 

 Kangaroo family, which affinity was further manifested by the form 

 and structure of the stomach. The premolars presented the great 

 antero posterior extent characteristic of the subgenus Dendrolagus : 

 they are trenchant, with many minute vertical grooves ; they play 

 upon each other like the blades of scissors, and must perform an im- 

 portant part in cutting off the leaves or fruit, or dividing after they 

 are detached, the natural objects of food of the Tree- Kangaroos : the 

 true molars are double-ridged transversely, as in the Macropodida 

 generally. 



The tongue is long, narrow, depressed, with a smooth and even 

 dorsum, showing three fossulate papillae at its base, arranged in a 

 triangle with the base turned forwards : the Macropus major has a 



