Sinclair: marsupialia of the santa cruz beds. 
357 
the lambdoidal crest expanded as a broad semicircular frill. The infra- 
orbital canal is double, neither branch being as large as the single canal 
in.Z?. excavata. If constant, this may prove to be a good specific char- 
acter. The skull is a fourth larger than in B. excavata . 
It is not yet possible to separate generic from specific characters in the 
skeleton, as B. tuberata is the only species in which the skeleton is at all 
well known. Its important features have already been noted in the de- 
scription of the genus. 
Measurements. 
U 
it 
Skull, length, premaxillae to lambdoidal crest 
“ width across jugal arches 
“ “ between orbits 
Face, length to anterior orbital border 
Cranium, length to anterior orbital border 
“ least width of brain case 
Palate, length from alveolus of median incisor to pala 
“ width between canines . 
“ “ “ posterior premolars 
“ “ “Mi . 
Mandible, length .... 
transverse diameter of condyle 
length of symphysis 
“ depth below posterior premolar 
“ “ “ M ¥ 
Superior dentition, length, median incisor to Mi 
“ “ of premolar series 
“ “ “ “ molar “ 
Inferior dentition, length, base of median incisor to M 
“ “ “ of premolar series 
“ “ “ “ molar “ 
Median upper incisor, width of crown 
Lateral “ “ “ “ “ . 
Alveolus of upper canine, length 
“ “ “ “ width 
Anterior superior premolar, antero-posterior diameter 
“ “ “ transverse 
Median “ “ antero-posterior 
“ “ “ transverse 
Posterior “ “ antero-posterior 
“ “ “ transverse 
Mi, antero-posterior diameter . 
“ transverse “ ... 
M-, antero-posterior “ 
“ transverse “ 
<< 
it 
o-narial border 
.230 
.160 
.062 
.076 
.141 
.027 
. 104 
.0245 
•037 
•075 
.186 
.0423 
.060 
.031 
.038 
•113 
•0333 
•045 
. 1025 
•035 
•0515 
.002 
.0036 
.0165 
■0135 
.0075 
.0047 
.010 
.0063 
.0145 
.009 
.012 
.0082 
.0126 
.0095 
