BY C. W. DE VIS. 
101 
Though the lower teeth are in proportion to the upper unusually 
broad, being scarcely a tenth narrower, the presence of similar 
accessory processes on corresponding parts of the masticatory 
surfaces assures us that in this instance molars of the upper and 
lower jaws are correctly referred one to the other. 
Form. 
Maxillary. — P. 4 in the maiden state unknown. The worn 
tooth (PL xvi. fig. 12) is irregularly subtriangular, attenuated at 
the fore end, its ledge much dilated posteriorly, but narrow at its 
anterior junction with the lobe, and without traces of transverse 
ridges. Crest subcentral in front, over exterior fourth behind. 
Mesial three-fifths of outer surface impressed, deeply at its posterior 
end : impressed surface with about four low vertical ribs; inner- 
surface with traces of numerous narrow vertical ribs. On the 
intero-posterior angle remains of a cusp. Diameters 14*7 : 7 "6; 
13*4 : 7*6. The tooth is equal in length to m. 4 . 
P. 3 unknown. 
Molars. — (PI. xvi. fig. 14). With one or more short broad 
flame-like folds on the posterior face of each lobe within the 
hollow triangle contained by the descending edges of the lobe; 
not infrequently the folds become plates which running together 
enclose the lower part of the inner half of the triangular space. 
The hind lobe of m. 4 has no distinct processes. Traces of the 
folds are persistent in well worn teeth with varying distinctness. 
Ma7idibulary. — P. 4 (PI. xvi. fig. 13) elongate, narrow anteriorly, 
suddenly widening posteriorly; mesial diameters 11 '5 x 4-3; 11*0 
x 4*0; 11*1 x 5.4. Crest central, posteriorly curving down- 
wards to the intero-posterior angle. Outer side of crown straight 
or slightly convex, with a more or less distinct mesial impression 
bearing about three vertical ribs; inner side conchoidal posteriorly 
with three strong ribs; anterior cusp more or less expanded and 
well defined. 
P. 8 is irregular, subelongate, tapering slowly to a pointed 
fore end. Crest on the inner side anteriorly, on the outer 
