BY C. W. DE VIS. 
85 
Dimensions. 
Mandibular. — The length of the entire series of cheek-teeth is 
94 -7 (1); of the series of true molars 8O0 (1); of the last three 
molars 58-3 (1); of the last two 39-4 and 41-6 (2); of the last 
22-0 and 22-1 (2); of m. 2 , m. 3 37*0 (1); of m. 3 22-1 (1); of m. 2 
20- 2 (1); of the premolar 15-0 (1); of mp. 4 18-5 (1). The width 
of m. 3 is from 12-3 to 14*2 (7). The anterior depth is 406 and 
48-3 (2); the posterior from 35*4 to 49*0 (10); the thickness from 
21- 8 to 29-9 (10). 
Maxillary. — The length of the first four cheek-teeth is 55*9 (1); 
of the first two molars 37*6 (2); of the last two 37 "9 (1); of m. 1 
21-2 and 21-5 (2); of m. 3 19-7 (1); of m. 2 20-5 and 2M (2). 
The width of m. 3 is from 15-8 to 16-6 (3). The length of the 
premolar is 15'0 (1). 
The mean widths of m. 3 , upper and lower, are to each other as 
13. 16*2, agreeing ver}^ nearly with those in H. agilis, H. ulabatus, 
H. stigmaticus, and 0. frenata. 
No gradations in size connect this species, which is rather 
numerously represented, with P. azael, to which it stands in much 
the same relation as does S. otuel to S. goliah; its inferiority in 
this respect is therefore characteristic. Not only so, but the 
differences between two of its dimensions and the corresponding- 
dimensions in P. azael transcend the range of individual variation 
in size which on the testimony of living Macropods can be allowed 
within a species. The mean widths of m. 3 in the two are 1 3 and 
18, or an excess in the latter approaching one-half of the former. 
The greatest living difference is found in P. penicillata, where it 
amounts to a third only; in H. dorsalis and H. wilcoxi it is still 
less. Again, the mean anterior depth of the mandible in P. 
parvus 44 '4 is in P. azael increased by more than one-half, and 
this far exceeds the nearest living approach to it which occurs in 
H. dorsalis where it is considerably less than one-half. Finally, 
the premolars of P. parvus are relatively much larger than those 
of P. azael. 
