wy 
1871.] i9 [Cope. 
terior one of the known species of Megalcnya, nor the reduced size, so 
that it remains to ascertain whether either of them is the first superior 
molar. (2.) The larger is evidently notso, because it has an obliquely- 
worn distal face, indicating the existence of another tooth beyond it in 
the opposite jaw. (8.) The opposite one is not the anterior molar, be- 
cause (a) its anterior dentinal face is worn horizontally, not obliquely 
backward, indicating an overlapping tooth ; (b) because the oblique wear 
of the dentine would, on the supposition that it is the first, be thrown 
on the posterior instead of the anterior faces of the other molars ; (c) and 
because its form is narrower than the other teeth, instead of wider as 
in other species. 
Confirmatory of this conclusion is the fact that no palate can be dis- 
covered among the fragments where it should be, were these teeth max- 
illaries. The question as to the relation of ends is settled by the fact 
that the plane of the crowns rises to the narrower, which would thus be 
anterior. Also the large tooth has the oblique surface for the last supe- 
rior molar, which the anterior has not. The fragments of the jaw indi- 
cate the same thing, rising (towards the coronoid process) at the large 
tooth and falling at the narrower. The latter, then, for the above rea- 
sons, I assume to be the anterior. 
M. 
Length of three juxtaposed Crowns. ....-.-0.seseeee cence eee tees 0.053 
fC AMLOLIOL CRO ws SUNT ON Cie ea. 548 ea. - a rleyin's sh ge ey ey vias oeree .018 
a oy OO OUUCE ONO so sted oe es a eee 018 
Width ye Oe a ee cect ats Sey sues cea Sec eke .02 
Length of last Oe UMUC T CMC bese ae ied iaislags ote he ote O14 
we os . TOOL. GUC si ital. Seco sis yep te ee 0016 
Width Mi Se ks a ee .02 
iength of, Shatt. frst COObM: ; sie cc echo icc eS oe oe tales ge oe 054 
There are five isolated molars of the same type as the above. Three 
of these are evidently anterior or second inferior molars, two of the left, 
side and one of the right. Their section is suboval, and all the details, 
size, &c., areas above described. Two others are like the second (or 
third) inferior molars. One of these is peculiar in being a little concave 
on the anterior face, the inner extremity very oblique, the other is more 
oval. = 
The question as to the specific relations of these inferior molars may be 
stated as follows. Their large size precludes the probability of their be- 
longing to either WM. tortulusor M. sphenodon. They appear to belong to 
one species, without doubt. The superior molars also belong to one 
species, and as no other species is represented in any thing like 
the same abundance, it is reasonable to suppose that these, with the most 
abundant of canine molars, belong to the same form of Megalonyx. The 
canine molars differ from those of JZ. lowodon, and the posterior upper 
molars from those of M. dissimilis. The disproportion between the sizes 
of the second and last inferior molars, with the narrow oval and triangu- 
