of American Geologists and Naturalists. | 105 
The third species mentioned is also the type of a new genus 
of Suiline Tachyderm. It was called Protocherus prismaticus : 
only the first and third molars, and a canine, all from the lower 
jaw, have been found. These teeth are from a locality fifteen 
miles distant from the place where the other bones were obtain 
_ The canine (left lower) is curved, and almost pointed ; the 
posterior. face is worn flat, the line separating the worn from the 
unworn portion is oblique as in Dicotyles; the external and in- 
ternal faces are slightly convex, and but little narrower than the 
ese face; they meet in well defined angles, the anterior edge 
ing scarcely rounded. Near the alveolar margin, on the ante- 
rior part, and extending on to the adjoining faces, is a deep space 
concave in a longitudinal direction, which appears to have been 
worn, by some agency unknown to the author. It bears some 
resemblance to the figure of a united fracture of a Hippopotamus 
tusk, (Owen, Odont., pl. 142., fig. 2.) The enamel is very brill- 
iant on the external and internal faces; on the wera face it 
| been worn off. The portion that remains of the inserted 
part of the tooth is nearly elliptical, the anterior part bring flat- 
tened, and very slightly impressed ; there is also a slight impres- 
sion on the inner surface. The first molar is quadrate; the 
crown is much worn, but presents remains of two large trans- 
Verse elevations, slightly connected in the middle, but without 
any ohana tubercle : the poe and — parts have 
’ g basal margins each connected in the middle with the 
eaten. ridge by a slight ikea. The intervening valley has 
alow angulated external margin, which does not extend on to 
the transverse ridges. 'The last molar is fractured, and the ante- 
rior lobe is almost destroyed, but enough remains to show that it 
Was similar to the second lobe. The tooth is elongate, narrowed, 
and subacute behind: it is divided by two very deep transverse 
valleys, into three large lobes: the anterior and middle of which 
are divided by a longitudinal impression into two cusps: there 
is no accessory tubercle ; the internal anterior, and external pos- 
terior cusps are prolonged towards each other by low elevations, 
Separated by a deep line: between these two lobes is a rough 
internal interspace, and a larger more elevated external one, 
is prolonged posteriorly to meet a large posterior lobe. obey: di- 
vided by an oblique line into two unequal cusps, the internal 
mee the larger and more elevated: this dividing line is a pro- 
longation of the same line which divides the other lobes, the 
tooth is. amet for the thickness and lustre of the enamel : 
e lobes are worn in such manner as to pre- 
sent pane tates meeting in well defined lines, like the edges of 
'h “affinities of the ‘animal -are rendered a apparent by the 
oing description; from the form of the canine, it must be 
40 i eo ripti 
Bkkere: BSrhizs, Vol. y, No. 13.—Jan. "1848. 14 
