232 
PATAGONIAN EXPEDITIONS : PALAEONTOLOGY. 
of the other species, indeed, than in any other known member of the sub- 
order. The sagittal crest is very high and descends quite steeply to the 
forehead. 
The dimensions in the following table are taken from No. 9532, A. M. 
N. H., an adult, still rather young, as is shown by the relatively small 
size of m-. 
Measurements. 
Upper dentition, length 
. .160 
M-, length 
.030 
I-, length (i. e. ant. -post, diam.) . 
. .007 
“ width 
.022 
“ width (i. e. transv. diam.) 
. .018 
Mj, length 
.021 
I-, length ..... 
. .0125 
M-j, length 
.031 
“ width ..... 
. .014 
“ width ...... 
.009 
I-, length 
. .005 
Skull, length in med. basal line . 
.246 
‘ ‘ width 
. .003 
“ fr. occ. cond. to prmx. . 
.270 
Upper canine, length . 
. .007 
Cranium, length fr. cond. to orb. . 
•157 
“ “ width . 
. .005 
width at constriction . 
•059 
Upper cheek-teeth series, length 
. .107 
Occiput, width at base 
•145 
Upper premolar series, length 
. .043 
“ over cond. . 
.065 
P-, length 
. .008 
Zygomatic arch, length fr. glen. cav. . 
.097 
“ width ..... 
. .006 
“ width (dors.-vent.) . 
.052 
P-, length ..... 
. .Oil 
Skull, zygomatic width 
.190 
“ width ..... 
. .011 
Face, length fr. orb. to prmx. 
.132 
P 5 -, length ..... 
. .0115 
“ width over lachrymals 
•095 
“ width 
. .0125 
“ “ “ prmx. 
•059 
P-, length 
. .013 
“ depth at m- .... 
.094 
“ width ..... 
. .016 
4 4 4 4 P 1 , • • • • 
.069 
Upper molar series, length . 
. .064 
Palate, length in median line 
•155 
M-, length .... 
. .018 
“ width at p- . 
.026 
“ width 
. .0225 
“ < < < < m 3. 
.066 
M-, length .... 
. .023 
Mandible, depth below m-g-. 
.056 
“ width ..... 
. .024 
The fore-limb and foot differ from those of A. ovinum even more than 
the comparative measurements would indicate. The distal end of the 
radius is much more massive and has a far larger and more rugose ex- 
pansion toward the ulnar side, and on the inner side of the dorsal face is 
a conspicuous tendinal sulcus not present in A. ovinum. The carpals are 
broader and heavier than in the latter and have more roughened dorsal 
faces. The metacarpals are longer and relatively much heavier and the 
tubercles for muscular attachment are decidedly more prominent. 
The dimensions are taken from No. 9184, A. M. N. H. 
