AMBLYPODA. 
183 
dactyla. In tlie latter respect, they agree with the Tapirs, but not with other 
Ungulates, excepting a few Rliinoceridoi. The cervical vertebrje are short, 
and not united by ball-and-socket joint, and are intermediate in character 
between those of Prohoscidia and other Ungulates. In both suborders, the 
scapula is acuminate at its superior border and expanded behind, as in 
Prohoscidia^ while the abrupt origin of its spine is a character of Prohoscidia, 
Artiodactyla, and many other Mammals, but not of Perissodactyla. In the 
rudimental spine and crest of the tibia, we have again especially Probos¬ 
cidian resemblances, which are confirmed by the shape of the ilium. This 
bone expands immediately from the acetabulum into a broad plate, which 
has a continuous convex crest, and is altogether different from the pedun¬ 
culate ilium of the Rhinoceros and Hippopotamus. 
As regards tile points in which the suborders differ, it may be observed 
that the Pantodonta in their dentition and femur resemble the Perissodactyla 
more than do the Binocerata, while the absence of alisphenoid canal in 
Coryjihodon is a suilline character, and the only one which I find in the 
group. In the form of the femur, the Dinocerata resemble closely the 
Prohoscidia, but in the presence of the alisphenoid canal they agree with 
both Perissodactyla and Prohoscidia. It is not unlikely that, in future, genera 
will be found which connect both these orders more nearly with primitive 
types of Artiodactyla, but as yet we are not acquainted with them. 
The order Amhlypoda was first defined by the writer in the Systematic 
Catalogue of the Vertebrata of the Eocene of New Mexico, published 
in April, 1875. The two snhorders Pantodonta and Dinocerata were originally 
defined by the writer in “The Short-footed Ungulata of Wyoming”, 
published March, 1873, in the following language: 
‘•No incisors; nasal bones elongate; astragalus articulating with both 
navicular and cuboid; no third trochanter.. Dinocerata. 
“Dentition complete, i. e., incisors present; ? nasal bones; astragalus 
articulating with both navicular and cuboid; a rudimental third 
trochanter... Pantodonta.^ 
The name Dinocerata was then proposed as a correction of ^^Dinocerea,^' 
originally introduced b}^ Professor Marsh* for the animals which it includes, 
* Ainer. Jour. Sci. and Arts, 1872, October, 1872 (separata September 27). 
