CliEODONTA. 
133 
height, and are separated by a pronounced notch. There is a narrow cin¬ 
gulum extending across their front. The heel supports two or three low 
cusps, of which the exterior sends an oblique ridge to the base of the inner 
of the anterior pair. No basal external or internal cingulum. Enamel 
smooth. The mandibular ramus is quite robust. 
Measurements. 
M. 
Length of the five posterior molars...... 0. 0125 
Length of the three true molars. 0. 0085 
Length of the penultimate molar.. 0. 0025 
Width of the same . . .. 0. 0018 
Depth of the ramus at penultimate molar. 0. 0045 
The jaw is nearly twice the size of that of the common Mole {Scalops 
aguaticus). 
Diacodon celatus, Cope. 
Plate xlv, fig. 20. 
System. Cat. Vert. Eocene New Mexico, U. S. Geog. Survs. W. of 100th M., 1875, p. 12 
The smallest Mammal of the Wasatch Eocene yet known is represented 
by a left mandibular ramus, which I found exposed in the face of a precipice 
of sandstone, on a peak of the bad-lands. It supports the three last molars, 
which have nearly the character of those of the species last described. The 
last molar is smaller than the others in the present animal, but equal to them 
in the D. alticuspis. The posterior part of the crown is deeply excavated, 
and supports on its outer angle a sharp cusp. The anterior cusps are tAvice 
as high. There is no external basal cingulum. The ramus is shallow, the 
inferior border rising to the masseterip fossa, which is deeply excavated. 
Measurements. 
M. 
Length of the ramus from the antepenultimate molar to the angle. 0.0100 
Length of the last three molars ...... 0.0048 
Length of the penultimate molar.. 0.0015 
Elevation of the same anteriorly. . 0.0013 
Depth of the ramus at the antepenultimate molar..... 0.0018 
This species resembled some of our very small Sorices in dimensions. 
