1888. ] 73 [Cope. 
The animal described is mature, and the crowns of the first and second 
true molars have lost their patterns by attrition. The fourth premolar is 
small, but is two-rooted, the anterior root nearly reaching the posterior 
edge of the canine alveolus. The third premolar is like it but larger, the 
second is still larger, and has the external cusp and internal cingulum 
spreading posteriorly as in the other species. The first premolar is wider 
than long and has but one external cusp; it has anterior and posterior, 
but no external nor internal cingula. The true molars have all the cin- 
gula but the internal. The third true molar has three transverse dentinal 
tracts besides the posterior cingulum, indicating three rows of cusps. The 
external cusp of the second row is distinct from the others and of conic 
form ; it is bounded externally by the cingulum. 
The canine has a single external median groove. Its section is trian- 
gular, but the anterior face is not su wide, and the posterior edge not so 
acute as in the B. subequans. The fossa for the inferior canine enters the 
premaxillary to a depth equal one-fourth that of the muzzle at that point. 
In the B. rostratus it excavates to a depth of one-half the muzzle. Of the 
superior incisive alveoli, the first is a little larger than the third, and the 
third a little larger than the second. 
Measurements of skull. ' 
M. 
Length from premaxillary bone to probable inion...... .250 
ee . a ‘© postorbital apex..... .175 
° e ‘¢ preorbital border.... .155 
os * a ‘« infraorbital foramen. .080 
s My Ss *« superior canine...... .0385 
a " S ‘* posterior nares...... .148 
den eth: Of Otic: DUUR woe en. ate hee Wieddeassae \OS4D. 
Width: of OW Dulles sss. te vows crs ves: jeg usta teas NOLS 
Foo Of OGCIPiIt. (HICHLESE yas «sie ee oy vice sue ventas 1020 
““ at zygoma at auditory meatus........ ie ect eiee ss LLU 
Le (2 ab frOnt Ob OF iti oc css es os oc cee LOU 
4¢. Of. bra Case COTestest) .ie..isc ce scnet eovstie 009) 
+f Sot: DOStOR DLENPOCCRSOS a sienida wits ce Cee Siiea UGG 
+¢ 46 facial CONSITICHON. 4 e.4 63 ss 2d ced ates ee 084 
‘<< o CAnING a ly.eOli: (external) 44.6 5 .a twee ee 000 
See Me - ON Palate ies Hikes ee Oe 
£< between: pr Mid. «sevice es Hise is 2 0ee 
af Wy sli es ee TS ae es a eae ee 
‘SOL POStOLIOR DULCE) swiss sowie cece ccs ee ewe 0105 
“© between otic bull.ac..vce.. ie ecieess cre SOLID 
< of foramen magnum, ¢is5scic.s cs aoe se ses. 018 
“Det ween-Orbits (least)... s.4bks oes ce css. s sie 081 
Vertical diameter of zygoma behind orbit............. .0225 
& e es “ UOLOLii se an Bousd. Soovoe 0225 
PROC. AMER. PHILOS. soc. xxv. 127. J. PRINTED APRIL 8, 1888. 
