BY C. W; DE VIS. 
123 
last three molars from 41*5 to 45*0 (3); of the last two from 31-2 
to 34-1 (7); m. 4 is 15-5 and 16-9 (2); the premolar from 9-0 to 
10-5 (5); the first four cheek-teeth from 437 to 46-7 (2); the first 
three molars from 40-0 to 45.0 (3); m 2 , m. 3 from 3(H to 32-0 (6); 
m. 3 from 15-6 to 17*6 (6); m. 2 12-6 (bis.). 
Young: P. 3 , mp. 4 , m. 1 , m. 2 , m. 3 are 56*7 and 63*5 (2); p. 3 , 
mp. 4 , m. 1 , m. 2 45-2 and 45-4 (2); p. 3 , mp. 4 , m. 1 are 35*5 (1); 
p. 3 , mp. 4 20-4 (1); p. 3 from 9-0 to 10-0 (6); mp. 4 , m. 1 , m. 2 from 
35-4 to 38 7 (3); mp. 4 , m. 1 26-5 (1); m. 1 , m. 2 25-8 and 277 (2); 
m. 3 from 14-2 to 164 (3). 
The widths of the lower and upper teeth are as 13 to 14; in 
M, giganteus the ratio is 7:8; in M. robustus 19:20; in most 
other recent species the difference is much greater than in M. 
giganteus. 
Tn mandibular dimensions M. magister has no special relation 
to either of the recent kangaroos. Though the length of its 
cheek-teeth is but little more than a fourth greater, the mean 
width of the series at m. 3 is more than twice as great, while the 
thickness of the mandible and its depth are only about one-half 
greater than in M. giganteus, robustus and rufus. In range of 
depth it somewhat exceeds the greatest attained by a recent 
species, H. dorsalis, to wit. 
Form. 
Mandibular. — P. 4 (PL xviii. fig. 12) is short, with mesial diame- 
ters 7"0 : 3*5. Anterior lobe the shorter, longitudinally com- 
pressed, lancet-shaped; the posterior single, or with its anterior 
two-fifths forming a subdivision obscurely 'defined by a vertical 
groove on the outer side, and a notch in the crest. Crest curving 
without interruption on to the intero-posterior cusp, which is only 
separated from the lobe by a shallow vertical groove on the upper 
mesial part of the posterior surface, and forms with it anteriorly 
a concave intero-posterior face. 
P. 3 (PL xviii. fig. 11) is short, with mesial diameters 8-9 : 4*5, 
similar to p. 4 in structure, but larger in size. The anterior lobe 
is relatively larger; the intero-posterior cusp is higher than the 
