I 8 6 PEL TEPHIL US 



simpler in structure tiian iiiose which follow. The dorsal 

 vertebrae a(iain are not fused together; the hiud-linibs are ii ve- 

 toed. All the plates of the carapace are arranged in definite 

 transverse rows; it has l)een 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 Peltcphilus, which is 

 perhaps rather an Armadillo than a Glyptodon. However, it 

 comes somewhat Ijetween the two, like Pro2)alaeohoplophorHS, with 

 which it may therefore be treated. A most singular feature 

 of this genus has been mentioned on p. 1^7 in connexion with 

 the skull in tlie 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 Mannnalia, it is noteworthy that the humerus 

 has been especially compared to that of the Monotreme. Pelte- 

 jjhllus differs from other Armadillos in having teeth in the front 

 of the jaws. The total number of teeth is twenty-eight, i.e. seven 

 in each half of each jaw. 



Sub-Okdei; 2. NOMAETHEA. 



As already explained, the Old -World Edentates differ from 

 the New-World forms in having normal dorsal vertebrae, that is 

 to say, without additional zygapophyses. That negative featm'e, 

 however, though combined with the positive fact that both the 

 Old-World forms feed upon ants, is hardly sufticient 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 A'^ark, the name 

 TuBULiDENTATA may be applied. 



