Chapter M

Breadth over nasal tuberosities ·132
Length of nasal tip (anterior to tuberosities) ·033
Circumference of maxillary projection near the tip ·208
Vertical diameter of squamosal ·058
Transverse diameter of ditto at malar articulation ·045
Length of centrum of dorsal vertebræ ·070
Height of ditto ·083
Breadth of ditto below costal surfaces ·097
Breadth of pedicle ·058
Length of transverse process ·056
Extreme breadth of transverse process ·061

Found at Henry's Fork.

Uintatherium robustum. Leidy.

Cont. to Ext. Vert. Faun., p. 96.

A fragmentary skeleton from Henry's Fork.

RODENTIA.

PARAMYS, Leidy.

"Extinct Vertebrate Fauna of the Western Territories," vol. i. Hayden's Surveys, p. 109 _et seq_.

This genus of the gnawers is very closely allied to the squirrels and marmots. Dr. Leidy sums up the generic characteristics of the teeth thus:

"The four lower molars are proportionately narrower than in squirrels and marmots, the fore-and-aft exceeding the transverse. The crowns are short, square, tuberculate, and enamelled.

"The lower jaw is proportionately shorter and deeper than in most known rodents; the reduction in length being mainly due to a less development of that part of the bone in advance of the molars. To compensate for the difference in length, and to make room to accommodate the incisors, these teeth reach further back than usual.

"The acute edge of the hiatus between the molars and incisors is almost on a level with the alveoli, of the teeth, instead of forming a deep concave notch, so conspicuous a feature in the jaws of the gnawers generally."

_Species known._--

{ Paramys delicatus, Leidy.
Loc. cit. { Paramys delicatior, Leidy.
{ Paramys delicatissimus, Leidy.
Paramys robustus, Marsh.

Am. Journ. Sc. v. iv., p. 218.

Paramys superbus, _sp. nov._

Established on a single lower incisor.

The species indicated by this specimen is the largest of the genus as yet known. The tooth is subtrihedral in section, is stout, and shows but little curvature. The anterior and lateral faces are broad, and the under margin to which the sides converge, is narrow. The enamel is thick and is inflected so as to cover a small portion of the sides as well as the front.

_Measurements._