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indicative of its dental peculiarities, and, as the present species agreed 
with the Armadillos in its dermal armour, he preferred the name of 
EeuPtodon clavipes, in relation to the peculiar modification of the 
oot. 
Mr. Owen then showed that the portions of tessellated armour 
described and figured by Weiss are identical in structure with those 
brought to England by Sir Woodbine Parish, and that the bones 
which were found with the armour in both cases belonged to animals 
specifically identical. He next entered upon the inquiry, Had the 
Megatherium a bony armour? and he concluded from a comparison of 
its skeleton with that of the Armadillos, that it had not. In the pelvis 
of the Armadillo there are twelve sacral vertebree anchylosed to- 
gether, and the spines of the vertebrz are greatly developed antero- 
posteriorly, forming a continuous vertical ridge of bone, bearing im- 
mediately the superincumbent weight. In the Megathere the sacral 
vertebre are only four in number, and are not anchylosed, and the 
spinous processes are comparatively small, not locked together, as in 
the Armadillos, but separated by intervals as in the Sloths. In the 
Armadillos, the weight of the cuirass is transferred from the sacrum 
to the thigh-bones by two points on each side. One of them, the 
ischium, is anchylosed to the posterior part of the sacrum, the other 
point is formed by the conversion of the iliac bone into a stout three- 
sided beam passing straight from the thigh-joint to abut against 
the anterior part of the sacrum, where the weight of the shell is 
greatest,—a structure which is wanting in the Megathere. In no 
species of Armadillo is the ilium expanded, while in the Megathere 
it is greatly developed, resembling that of the Elephant in size, form, 
and position ; and among the Edentata the nearest approach in this 
portion of the skeleton is to be found among the Sloths and Ant-eaters. 
The most striking point however, in the structure of the Armadillos, 
with reference to the support of a bony covering, is the remarkable 
production of a part of the vertebra from above the anterior articular 
process on each side, in a straight direction upwards, outwards, and 
forwards, to nearly the height of the true spinous processes. Now, 
these oblique processes, which are developed only in the loricated 
Edentata, beautifully correspond in form and use with the tie-bearers 
in the architecture of a roof, and are entirely wanting in the Me- 
gathere, the structure of this part of the vertebral column of that 
animal corresponding with the character of the vertebrze of the hair- 
clad Sloths and Ant-eaters. Mr.Owen noticed other supposed adap- 
tations in the skeleton of the Megathere to sustain a bony covering, 
as the breadth of the ribs, but the ribs of the Sloths and Ant-eaters 
are broader than those of the Armadillos. 
The paper contained a tabular account of the discovery of twelve 
skeletons of the Megathere, and in no instance did any portion of 
bony armour occur with or near the bones. A notice was also given 
of the remains of a Glyptodon, found in the left bank of the Pedernal 
before its junction with the Sala, an affluent of the Rio Sante, near 
Monte Video, and preserved in the museum of that town. From 
the accounts which have been given of these remains they appear to 
