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Show 360 PROF. W. H. FLOWER ON THE EDENTATA. [Apr. 18, Cycloturus. 3. The DASYPODID^E, which may be divided into two sections, one containing the genus Tatusia, 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 Armadillos1; and another, including the genera Dasypus, Xenurus, Priodon, Toly-peutes, and Chlamydophorus, 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 M A N I D ^ E , containing about seven species, the slight modifications of which are scarcely worthy of being considered generic. 5. The O R Y C T E R O P O D I D ^ E , with one genus containing two closely allied local forms and species. The three first-named families are inhabitants of the New, the last two of the Old World. The families of which all the members are extinct are the M E G A - THERiiD^Eand G L Y P T O D O N T I D ^ E , both American and post-Tertiary, the one related to the Bradypodida, and the other to the Dasypo-didce. The Tertiary forms are less known; but those of the N ew World may be provisionally grouped under Marsh's name of M O R O - PODID^E, and those of the Old World as M A C R O T H E R H D ^ E . 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 P H Y L L O P H A G A , P H Y T O P H A G A , or T A R - DIGRADA, containing the Bradypodida alone ; and the E N T O M O - P H A G A or V E R M I L I N G U A , 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 Manida, are invariably closely associated with the New- World Anteaters or the Myrmecophagidce, 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 m y 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 Manida 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 submaxillary 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 probably lies in the fact that in countries where termites and similar insects flourish, various distinct forms of vertebrates 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. 1 See Garrod, " Notes on the Anatomy of Tolypeutes tricinctus, with remarks on other Armadillos," Proc. Zool. Soc. 1878, p. 222. |