90 
FOSSIL JAWS OF MACROPODtDM, 
of them being the outer one on the intero-anterior face of the hind 
lobe in the lower and intero-posterior face of the fore lobe of the 
upper teeth. Hinder surface of molars with strong ascending 
folds, one or two on the lower, two or three on the upper (PL xv. 
figs. 8-9). Upper premolar short with a broad ledge, not extend- 
ing beyond the posterior three-fifths of its inner side; its cavity 
traversed by a longitudinal sinuous ridge. Lower premolar sub- 
triangular with a group of sinuous folds within the posterior cleft. 
Dimensions. 
Mandible. — The entire series of cheek-teeth varies from 82*5 to 
93-7 (6); p. 4 , m. 1 , m. 2 , m. 3 measure 68-0 (1); m. 1 , m. 2 , m. 3 53-0 
(2); m. 1 , m. 2 34-2 (1); m. 2 , m. 3 , m. 4 from 58-1 to 65-5 (2); m. 4 22-2 
(1); mp. 4 13-4 (1). The premolar is from 12-5 to 14-5 (5). The 
width of m. 3 ranges from 15*0 to 19 -8 (10); its length being from 
18*4 to 21*5 (10). The anterior depth of the mandible is from 
50-0 to 60-0 (7); the posterior depth from 37-0 to 52-5 (6); the 
thickness from 34*7 to 42-5 (7). The entire length fore and aft 
is 147-5 (1). 
Maxilla. — The molars m. 2 , m. 3 ,m. 4 measure together 51 '5 (1); 
m. 2 , m. 3 from 38-5 to 42-1 (2); p. 3 , mp. 4 , m 1 , m. 2 46-6 (1). An 
immature premolar has diameters 12*0 x 9-4; the milk premolar 
is 9-2 in length. 
With one exception all these dimensions come well within the 
allowable limits of range in a species. The width of the teeth 
differs to an extent which is nearly a third of its minimum; this 
is sensibly greater than in the three living species which show the 
greatest latitude in this respect— 31. giganteus, H. agilis, and H. 
ruficollis — but the difference is too small to stand as a lone 
objection to the fusion of S. rapha with S. goliah. 
Form of teeth. 
Mandibular. — P. 4 (PI. xv. fig. 7.) Generally triangular, with 
rounded sides and angles, rarely an irregular suboval. Outer 
surface of crown impressed at its anterior two-fifths or thereabouts, 
