186 PELTEPHILUS CHAP. 
simpler in structure than those which follow. The dorsal 
vertebrae again are not fused together; the hind-limbs are five- 
toed. All the plates of the carapace are arranged in definite 
transverse rows; it has been observed, too, that some of the 
anterior scutes overlap like those of the Armadillos, to which this 
animal possesses further likenesses in the exclusion of the 
maxillae from the border of the nostril (a Glyptodont character), 
and the comparative feebleness of the scutes. 
A primitive genus also appears to be Peltephilus, which is 
perhaps rather an Armadillo than a Glyptodon. However, it 
comes somewhat between the two, like Propalaeohoplophorus, with 
which it may therefore be treated. A most singular feature 
of this genus has been mentioned on p. 27 in connexion with 
the skull in the Mammalia generally. That is the fact that 
a portion of the squamosal surrounding the articular facet for 
the lower jaw is separated by a suture from the rest of that 
bone, and is therefore obviously suggestive of the quadrate in 
the lower Vertebrates. As in certain Armadillos and Glyptodons, 
etc., the pterygoids appear in this genus to have taken a share in 
the formation of the hard palate. The plates of the carapace were 
movable, as is shown by the fact that they sometimes slightly 
overlap. In view of the possible origin of the Edentates from 
lowly-organised Mammalia, it is noteworthy that the humerus 
has been especially compared to that of the Monotreme.  Pe/te- 
philus differs from other Armadillos in having teeth in the front 
of the jaws. The total number of teeth is twenty-eight, 7.e. seven 
in each half of each jaw. 
SuB-OrDER 2. NOMARTHRA. 
As already explained, the Old-World Edentates differ from 
the New-World forms in having normal dorsal vertebrae, that 1s 
to say, without additional zygapophyses. That negative feature, 
however, though combined with the positive fact that both the 
Old-World forms feed upon ants, is hardly sufficient to outweigh 
the many structural differences which distinguish the Oryctero- 
podidae from the Manidae; which will be placed therefore’, in 
different groups. To that containing the Aard Vark, the name 
TUBULIDENTATA may be applied. 
