158 
T^NTODONTA. 
investiture and undivided roots in the genus Calamodon, features essen¬ 
tially characteristic of the Edentata. 
Thus we have in the Tmniodonta the first hint as to the relations of the 
Edentata in early Tertiary time. 
ECTOGANUS, Cope. 
Report Vert. Foss. New Mexico, U. S. Geog. Survs. W. of 100th M., 1874, p. 4; Id., Ann. 
Report U. S. Geog. Survs. W. of 100th M., 1874, p. 116; System. Cat. Vert. 
Eocene New Mexico, U. S. Geog. Survs. W. of 100th M., 1875, p. G. 
This genus rests on a number of remains of the crania of two 
species, including principally teeth, in a good state of preservation, all 
found in appropriate relations by the writer. The teeth include incisors, 
molars, and premolars, it is believed, of both superior and inferior series. 
There are two types of gliriform incisor teeth, and of one of these, in 
the largest species, three sizes. In the inferior, the teeth are elongate, com¬ 
pressed, convex in both directions on the anterior face; and are convex or 
angulate in section at the posterior face; the enamel is confined to a band 
on the anterior face, extending more or less on one side or the other, the 
naked dentine extending prominently backward at the middle and basal 
portion of the shaft. 
The teeth of the other type correspond with those referred to the upper 
jaw in the genus Calamodon. Like them, they are flattened, and have 
a convex, enamel-coated, anterior face, and a similarly coated posterior face, 
which converges toward the anterior, instead of being parallel with it, as is 
the case in Calamodon. In E. gliriformis, the unworn apex is partially 
preserved, and presents the peculiarity of having two distinct terminations, 
one for each enamel face. Between the two, there is a deep notch, which 
is oblique, and also extends up one side of the tooth for a greater or less 
distance, according to the species. The superior apex is entirely encased 
with enamel. The enamel bands are oblique in the transverse direction as 
in Calamodon, looking to the side which I suspect to be the external. The 
other side is flat. This peculiar form induced me to suppose at one time 
that this body consisted of two distinct teeth connected by the alveolar wall, 
a view which I subsequently corrected. 
There are three molars of the superior, and several of the inferior series 
