116 
FOSSIL JAWS OF M ACBOPODID^, 
all the true molars; nine with sundry molars, and two young 
rami with mp. 4 , m. 1 , m. 2 . 
Halmaturus cooperi, Ow. 
Molars with curved crests, rounded angles and strong links. 
Lower premolars elongate, narrow, tumid on intero-posterior 
angle, but developing there no cusp; crest tridentate. Molars 
smooth without groove or basal talon posteriorly. Upper pre- 
molar ledged, with an intero-posterior cusp; molars smooth with 
adpressed folds posteriorly. Lower mandibular contour undula- 
tory. Palate entire. \ 
Dimensions. 
Mandibular. — The full series of cheek-teeth measures in adults 
from 38-6 to 42-5 (3); in adolescents from 44-4 to 50-7 (3). The 
true molars vary from 34*0 to 39*5 (5); m. 2 , m. 3 , m. 4 from 28*5 
to 33 6 (9), but in an adolescent tooth reach 35*7; m. :3 , m. 4 are 
from 20-5 to 25 0 (7); m 4 from 11-8 to 12 8 (4). The first four 
cheek-teeth range [from 29-3 to 37*0 (15); the first three from 
29-3 to 38 4 (4). The premolar varies from 7'0 to 9-6 (6). The 
width of m.* 3 ranges from 6 5 to 8 5, doubtfully to 9-6 (54). The 
anterior depth in adults is from 17*5 to 27*3 (17); in adolescents 
17 6 to 23-5 (17); the posterior in adults from 174 to 26-6 (18); 
in adolescents from 15 0 to 21 -5 (6). The external length is from 
65-7 to 78-0 in adults (3). The internal from 53 2 to 667 (6); 
the thickness from 11 -4 to 16*2 (23). In the young the first 
three cheek-teeth are 23-1 and 24-0 (2); mp. 4 , m. 1 16-0; m. 1 9-9; 
m. 1 , m. 2 , m. 3 26'6 and 29-5; m.^m. 2 from 17 0 to 21*6 (4); m. 2 , 
m. 3 from 20-0 to 22-8 (5); m. :3 from 10-1 to 12-5 (4); p. 3 6-8 and 
7-7 (2). 
Maxillary.- — The entire set of cheek-teeth is 50*2; m. 1 , m 2 
23-0; m. 2 , m. :3 23-3; and p. 4 10-5. Width of m. :J 9-5. 
Form. 
Mandibular. — P. 4 (PL xvn. fig. 25) irregularly ovate, diameters 
8 '5 x 3"1; crest subcentral, tridentate. Crown mesially com- 
pressed; the compression defining an anterior cusp. Mesial cusp 
