ON THE MOLAR SERIES OE RHINOCEROS TICHORHINTJS. 533 
Measurements : 
Maximum 
Co 
085 
(2) 
. 0.75 
(3) 
. 0*65 
(4) 
• 
Magdeburgh. 
Average 
078 
. 0*65 
. 0*66 
. 2*6 
Minimum 
075 
. 06 
. 0.63 
. 2*5 
Wookey Hole. 
2. Pm 3. The median groove of the Pm 3 is far more vertical, and 
more strongly marked that in Pin 2, and is terminated interiorly at 
an average distance of 058 inches from the tumid base of crown. 
The two costae on the anterior area are faintly defined. The valleys 
are deep, and well marked. 
Inch. 
Maximum height of anterior area.1*7 
„ „ posterior area ....... T45 
Measurements: 
(l) (2) (3) (4) 
Maximum TOG 0'9 . 0 9 3*8 . Caswell Bay. 
Average . 0*96 0*83 . 0*86 3*46 . 
Minimum 0*88 0*76 . 0*85 3*4 . Wookey Hole. 
3. Pm 4. In Premolar 4 the anterior area is flattened, and 
traversed by a diagonal groove, more or less deep, separating the first 
from the second costa, the latter of which, more prominent than the 
fomer, is isosceles-triangular, with a tumid base. The median groove, 
deeper than in Pm 3, is terminated interiorly, at an average distance 
of 0*45 inches from the base of crown. 
Inches. 
Maximum height of anterior area.2*22 
„ ,, posterior area.1*85 
Measurements: 
(i) 
(2) 
(3) 
(4) 
Maximum 
. 1*4 
103 . 
1*08 
4*6 . 
Ilford. 
Average 
. 1*23 
103 . 
1*0 
4T 
Minimum 
. 1T5 
ITS . 
1*08 
4 . 
Wookey Hole. 
4. M l. In 
M 1, as in the two following molars, the posterior collis 
is, relatively to the other two, much larger than in the Premolar 
series, and the median groove traverses the base of the crown. 
Inches. 
Maximum height of anterior area ... . . . .2*2 
“ „ posterior area.1*9 
Measurements: 
(1) (2) (3) (4) 
Maximum . 155 1*1 . IT 5*1 . Ilford. 
Average . 1*39 1*17 . 1*12 4*64 
Minimum . 1*25 1*15 . 1*15 4*5 
