2G4 
PHASCOLARCTUS cinereos. 
vertical direction, in the adult. The pterygoid processes of 
the occipital hones are much elongated,— 10 lines in length 
in an adult skull. The posterior palatine openings are by no 
means large, as compared with the Phalangers proper, and 
are confined to the palatine hones, which assume the form of 
a vertical plate, of £ of an inch in depth, behind the palatine 
openings in question. 
In the lower jaw, the points most worthy of notice are, — 
the great depth of the rami, the angle being less twisted in- 
wards than in most other Marsupials—(in this respect resem¬ 
bling the extinct Diprotodon and Nototherium ); the sym¬ 
physis menii being more extended, and the rami more 
firmly united at this part, than in the typical Phalangers. The 
four hindermost incisors of the upper jaw and the canines 
are proportionately smaller than in the animals just men¬ 
tioned, and the molar teeth are larger, and the four tubercles, 
which the crowns of the true molars present, are more 
angular, having each the form of a three-sided pyramid, or 
nearly so. 
The following admeasurements are taken from a skull of an 
adult Koala, in the Hunterian Museum:— 
Inches. Lines. 
Length of sknU ... .5 0 
Width beneath orbits ... ... . 2 8 
Length of nasal bones . ... 1 3$ 
Width of ditto behind ... ... 1 2 
41 44 at the apex .0 10 
Length of zygoma. 2 11J 
Greatest depth of ditto ... ... . () 10 
From anterior root of zygoma to apex of inter- 
m&xillaries . 1 c 
Length of palate, including the palatine bones ... 2 4 
Width of ditto between premolars . 0 0 
Three upper incisor teeth, taken together ... 0 4$ 
From posterior incisor to canine ... ... ... 0 2 
From canine to prcmolar ... ... ... 0 4 
Length of the five molars, taken together. 1 5 
Length of lower jaw, measuring to apex of angle 3 10 
Height, measuring from apex of corouoid process 2 6 
