82 
FOSSIL JAWS OF MACROPODID^E, 
Dimensions. 
Mandibular . — The length of the first three cheek-teeth is 66*1, 
of the premolar 17*0, of m. 3 29-5, of p. 3 , mp. 4 , m. 1 , m. 2 6O0. 
The width of m. 3 is 19*0. The anterior depth of the mandible is 
61-5; the thickness 33-5. 
Maxillary. — From figure and cast. The entire length of the 
cheek-teeth is from 117 5 to 122-5, the premolar diameters 18*0 
x 18-0, m. 1 m. 2 are 55*5, m. 3 31'8. The width of m. 3 is from 
20-5 to 23-1. The breadth of the palate is from 100-0 to 103-2. 
The lower molars are proportionately narrow, but not more so 
than in the existing Macropods, M. giganteus, H. agilis, and H. 
rvficollis. 
Form of teeth. 
Maxillary. — The premolar p. 4 (PL xiv. fig. 5) is an almost 
regular equilateral triangle with convex sides and angles. From 
a narrow basal rim or talon, which however seems to be restricted 
to the inner side, the fore end of the crown slopes gently upwards 
to the horizontally abraded surface of the two cusps. Of these 
the smaller is placed over the intero-posterior angle, the larger 
over the middle of the outer side of the base. The cusps are 
defined by a deep indent between their posterior surfaces, anteri- 
orly by a depression in the inclined plane in front. The posterior 
basal talon runs from the outer angle to the middle of the hinder 
surface of the inner cusp. Opposite the posterior indent the 
talon is long, but behind the outer cusp where it is feebly linked 
to the middle of the base of that cusp, short. 
Molars. — In these as they appear in the cast the anterior basal 
talons and their linking ridges are distinct, but in the anterior 
teeth appear chiefly on the inner side, the posterior talons appear- 
ing only on the outer; but on the free surface of m. 4 (PL xiv. fig. 
6) the hinder talon is seen to extend round to the inner end of 
the base and to send upwards a strong linking ridge towards the 
inner end of the crest of the lobe before it. The mesial links run 
from centre to centre of the lobes which cross the line of the 
teeth at an oblique angle. The indications afforded by the cast 
