360 PROF. W. H. FLOWER ON THE EDENTATA. [Apt. IS, 



Cycloiurus. 3. The Dasypodid^, which may he divided into two 

 sections, one containing the genus Tatusio, which, in the presence of 

 milk-teeth, the structure of the fore feet, as well as in many characters 

 of the visceral anatomy, stands apart from all the other Armadillos' ; 

 and another, including the genera Dasypus, Xenurus, Priodoti, Toly- 

 peutes, and OfUamydophoi-us, which are clearly all modifications of 

 a common type, although the last-named shows such a striking 

 difference in the character of its dermal armature that it might make a 

 section apart, if its internal structure were not so closely similar to that 

 of Dasypus. 4. The Manid^, containing about seven species, the 

 slight modifications of which are scarcely worthy of being considered 

 generic. 5. The ORYCTEROPODiDiE, with one genus containing 

 two closely allied local forms and species. The three first-named 

 families are inliahitants of the New, the last two of the Old World. 

 The families of which all the members are extinct are the Mega- 

 THERiiD^and Glyptodontid.e, both American and post-Tertiary, 

 the one related to the Bradyporlidce, and the other to the Basypo- 

 dida. The Tertiary forms are less known ; but those of the New 

 World may be provisionally grouped under Marsh's name of MoRO- 

 PODJD.*:, and tliose of the Old World as Macrotheriid^. 



As to the mutual relationship of these families, it has been 

 customary with all recent zoologists to group them into two divisions, 

 often called suborders : — the Phyllophaga, Phytophaga, or Tar- 

 digrada, containing the Bradypodidce. alone ; and the Entomo- 

 PHAGA or Vermilingua, including all the others, unless, as in 

 some systems, Orycteropus is placed apart as forming a distinct 

 section. 



Whether these distinct suborders are adopted, or the families 

 merely arranged in their supposed relationship, the Old-World Ant- 

 eaters, or Manidcs, are invariably closely associated with the New- 

 World Anteaters or the Myi-mecophagidcs, and the latter are widely 

 separated from the Sloths. 



This being (I think I am not wrong in saying) the view universally 

 accepted at the present time, it is my purpose to investigate it a 

 little more closely than has hitherto been done, and to see whether 

 it is really based upon important structural relations, or only upon 

 what may be called superficial or adaptive modifications. 



The bonds which unite the ManidcB to the MyrmecophagidcE are 

 mainly to be found in the structure of the mouth, especially the 

 extensile character of the tongue, the great development of the sub- 

 maxillary glands, and absence of teeth. These characters are 

 exactly analogous to those found in the Echidna among Monotremes, 

 the Woodpeckers among Birds, and the Chameleon among Reptiles. 

 The explanation proljably lies in the fact that in countries where 

 termites and similar insects flourish, various distinct forms of verte- 

 brates have become modified in special relation to this abundance 

 of nutritious food, which could only be made available by a peculiar 

 structure of the alimentary organs. 



' See Garrod, " Notes on the Anatomy of Tolypeutes tricinctus, with remarks 

 on other Armadillos," Proc. Zool. Soe. 1878, p. 222. 



