190 EDENTATA 



of Argentina, described as Promegatherium and Promylodon, are 

 respectively distinguished from Megatherium and Mylodon by 

 the presence of bands of enamel on the teeth, which points 

 to the descent of the Edentates from mammals with enamelled 

 teeth. 



The Tertiary North American forms described as Moropus and 

 Morotherium, 1 and originally regarded as Edentates, would appear to 

 be aberrant Ungulates. 



Family MYRMECOPHAGID^E. 



Externally clothed with hair. No teeth. Head elongated. 

 Mouth tubular, with a small terminal aperture, through which the 

 long, vermiform tongue, covered with the viscid secretion of the 

 enormous submaxillary glands, is rapidly protruded in feeding, and 

 withdrawn again with the adhering particles of aliment, which are 

 then sucked into the pharynx. Clavicles rudimentary. In the 

 manus, the third toe is greatly developed, and has a long falcate 

 claw; the others are reduced or suppressed. The pes has four or 

 five subequal digits with claws. Posterior dorsal and lumbar 

 vertebrae, with additional interlocking zygapophyses. Tail long, 

 sometimes prehensile. Uterus simple. Placenta dome -like or 

 discoidal. Brain fairly convoluted, and with a large corpus cal- 

 losum and anterior commissure. The animals of this family are 

 the " Anteaters " par excellence. They feed exclusively on animal 

 substances, mostly insects. One species is terrestrial, the others 

 arboreal ; none burrow in the ground. They are all inhabitants of 

 the Neotropical region. 



The reproductive organs, as noticed on p. 181, are of the 

 same general type as in the Bradypodidce. 



Myrmecvphaga. 2 Skull greatly elongated and narrow, its upper 

 surface smooth and cylindriform. Anteriorly the face is produced 

 into a long, tubular rostrum, rounded above and flattened below, 

 with terminal nares, and composed of the mesethmoid ossified 

 for more than half its length, the vomer, the maxillae, and the long 

 and narrow nasal bones, the premaxillae being extremely short and 

 confined to the margin of the anterior nares. The zygomatic arch 

 is incomplete, the styliform jugal only articulating with the maxilla 

 in front, and not reaching to the very short zygomatic process of 

 the squamosal. The lachrymal foramen is in front of the margin of 

 the orbit. There are no postorbital processes to the frontals, or any 

 other demarcation between the orbits and the temporal fossae. Palate 

 extremely elongated, and produced backwards as far as the level of 



1 See E. D. Cape, Amer. Naturalist, vol. xxiii. p. \52 (1889). . 

 2 Linn. Syst. Nat. 12th ed. vol. i. p. 51 (1766). 





