An American Species of Paleotherium. 249 
fifteen inches, its depth from the highest point of the ramus 
(a) to the lowest (6), is nine and a half inches: it narrows 
regularly forward so as to measure only three and a half inches 
rom the lower surface of the bone at (d), to the alveolar process 
of the antepenultimate tooth at (c). The inner surface of the 
Fig. 1. 
One-fourth the natural size. ; 
bone is more uniform, being marked merely by depressions for 
the attachment of muscles. The alveolar portion is here very 
prominent and well rounded, the teeth being planted more than 
an inch from a vertical line which is tangential to the inner surface 
of the bone. It is covered in places with a concretionary matter 
The last molar tooth has the three lobes of the Palmotieny 4 
as shown in fig. 2. The inner surface is nearly smooth a 
long to the anterior lobe, the same to the middle, and 1} inches 
to the posterior. In an upper view, the two larger lobes have 
a deltoid form, with the sides somewhat convex, and a rounded 
outer angle. The thickness through from the outer to the op- 
posite side, is 13 inches. ‘The enamel of the inner side folds 
over the surface, covering nearly a semicircular space, an leav- 
ing between it and the edge of the posterior enamel, a sub-cres- 
cent-shaped space (deltoido-lunate ) of dentine, somewhat concave, 
which is nearly seven-eighths of an inch broad at its widest part. 
Econp Serizs, Vol. II], No, 8.—March, 1847. 32 
