54 
OREODON. 
- The specimen corresponds in its proportions and details with specimen 2 
VI. upper part of Fig. 4.) 
From the collection of Dr. Owen. 
MEASUREMENTS. 
Length of series of upper molars 
Breadth of face at infra-orbitar foramina 
Distance between supra-orbitar foramina 
Distance between frontal angular processes 
Inches. 
° 
a“ 
. (Plate 
Lines. 
1 
1} 
4 
8} 
4. The skull accompanied by the right side of the lower jaw of a young animal. 
® The former has the posterior and superior portions of the cranium and the nose 
away; the latter the ramus and symphysis. 
The upper jaw contains on the left side the molar series nearly complete, con- 
sisting of the first permanent premolar, the temporary molars, and the succeeding 
two permanent true molars which are fully protruded. 
The portion of lower jaw contains two temporary molars, and the succeeding 
broken 
two permanent molars. 
The forehead of this specimen is remarkable for its flatness; being much more 
arched in the adult. (Plate V. Figs. 3,4; VI. Figs. 6, 7.) 
From the collection of Dr. Owen. 
Average Measurements of Specimens of OREODON GRACILIS. 
Estimated length from summit of inion to incisive alyeoli 
Breadth below the orbit at the maxillo-malar suture 
Breadth of cranium at most prominent portion of temporal foasee 
Breadth of cranium at narrowest portion 
Estimated length of sagittal crest 
Length of forehead in median line : 
Breadth of forehead at middle of post-orbital nie 
Breadth of face from above the lachrymal tubercle 
Breadth of face at infra-orbitar foramina 
Breadth of face between ends of frontal angular processes 
Height from middle palate suture to fronto-nasal 
Height from middle palate suture on a line with the first premolar 
Diameter of the orbit 
Breadth of palate between fourth OES 
Depth of lower jaw at last molar 
Depth of lower jaw at third premolar 
Length of series of upper molars 
Length of series of lower molars 
Length of series of upper true molars 
Length of series of lower true molars 
Antero-posterior diameter of upper middle true mela 
Antero-posterior diameter of upper fourth premolar 
Antero-posterior diameter of last lower molar 
Antero-posterior diameter of second lower true molar 
Antero-posterior diameter of third lower premolar 
Inches. 
4 
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