50 THE DESEADO FORMATION OF PATAGONIA 
RESTORATION 
In order to get a comparison of what is known of this 
form with Theosodon | have outlined a restoration of the 
animal as a whole, realizing that some essential parts are 
lacking, but the general proportions can hardly vary greatly 
from those given. It appears, first, that this form has 
an unusually short back. Though the limbs and lower 
jaw are > the length of those of Theosodon garrettorum, 
the vertebrae are 3 as long. I have assumed that the 
number of vertebrae would prove to be the same as in 
Theosodon. While the limb bones are 2 as long as in the 
Theosodon, they are relatively half again as heavy and with 
the processes much more developed. The greatest differ- 
ence is found in the tarsus which is only 3 as long as that 
of Theosodon, though relatively as heavy, and the foot 
was carried in a nearly plantigrade position the heel raised 
but a little from the ground, though the anticular ends of 
the metatarsals and the phalanges indicate that there was 
a considerable freedom of movement of the various ele- 
ments. The form seems to be fairly close to the ancestral 
types such as Lambdaconus of the Casamayor, the limbs 
of which, however, are entirely unknown, but I should 
expect that when found these earlier forms would prove 
to be approximately plantigrade. 
Coniopternium Ameghino 
Coniopternium Amegh., 1895 Bol. Inst. Geog. Argen., t. 15, p. 632. 
Coniopternium Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 453. 
The genus is based on a calcaneum and astragulus of 
the macrauchenid type, but of unusually large size. The 
real generic characters are not evident in the description, 
but the presence of these bones, and of three cervical verte- 
brae, which we also found, indicating a macrauchenid of 
about the same size, are evidence that a form larger than 
the Santa Cruz representatives will turn up in the Deseado 
beds, for which this name may be reserved. The material 
is described under the specific name C. andinum. 
